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Index: stable/12/contrib/tzdata/NEWS
===================================================================
--- stable/12/contrib/tzdata/NEWS (revision 352352)
+++ stable/12/contrib/tzdata/NEWS (revision 352353)
@@ -1,4862 +1,4937 @@
News for the tz database
+Release 2019c - 2019-09-11 08:59:48 -0700
+
+ Briefly:
+ Fiji observes DST from 2019-11-10 to 2020-01-12.
+ Norfolk Island starts observing Australian-style DST.
+
+ Changes to future timestamps
+
+ Fiji's next DST transitions will be 2019-11-10 and 2020-01-12
+ instead of 2019-11-03 and 2020-01-19. (Thanks to Raymond Kumar.)
+ Adjust future guesses accordingly.
+
+ Norfolk Island will observe Australian-style DST starting in
+ spring 2019. The first transition is on 2019-10-06. (Thanks to
+ Kyle Czech and Michael Deckers.)
+
+ Changes to past timestamps
+
+ Many corrections to time in Turkey from 1940 through 1985.
+ (Thanks to Oya Vulaş via Alois Treindl, and to Kıvanç Yazan.)
+
+ The Norfolk Island 1975-03-02 transition was at 02:00 standard
+ time, not 02:00 DST. (Thanks to Michael Deckers.)
+
+ South Korea observed DST from 1948 through 1951. Although this
+ info was supposed to appear in release 2014j, a typo inadvertently
+ suppressed the change. (Thanks to Alois Treindl.)
+
+ Detroit observed DST in 1967 and 1968 following the US DST rules,
+ except that its 1967 DST began on June 14 at 00:01. (Thanks to
+ Alois Treindl for pointing out that the old data entries were
+ probably wrong.)
+
+ Fix several errors in pre-1970 transitions in Perry County, IN.
+ (Thanks to Alois Triendl for pointing out the 1967/9 errors.)
+
+ Edmonton did not observe DST in 1967 or 1969. In 1946 Vancouver
+ ended DST on 09-29 not 10-13, and Vienna ended DST on 10-07 not
+ 10-06. In 1945 Königsberg (now Kaliningrad) switched from +01/+02
+ to +02/+03 on 04-10 not 01-01, and its +02/+03 is abbreviated
+ EET/EEST, not CET/CEST. (Thanks to Alois Triendl.) In 1946
+ Königsberg switched to +03 on 04-07 not 01-01.
+
+ In 1946 Louisville switched from CST to CDT on 04-28 at 00:01, not
+ 01-01 at 00:00. (Thanks to Alois Treindl and Michael Deckers.)
+ Also, it switched from CST to CDT on 1950-04-30, not 1947-04-27.
+
+ The 1892-05-01 transition in Brussels was at 00:17:30, not at noon.
+ (Thanks to Michael Deckers.)
+
+ Changes to past time zone abbreviations and DST flags
+
+ Hong Kong Winter Time, observed from 1941-10-01 to 1941-12-25,
+ is now flagged as DST and is abbreviated HKWT not HKT.
+
+ Changes to code
+
+ leapseconds.awk now relies only on its input data, rather than
+ also relying on its comments. (Inspired by code from Dennis
+ Ferguson and Chris Woodbury.)
+
+ The code now defends against CRLFs in leap-seconds.list.
+ (Thanks to Brian Inglis and Chris Woodbury.)
+
+ Changes to documentation and commentary
+
+ theory.html discusses leap seconds. (Thanks to Steve Summit.)
+
+ Nashville's newspapers dueled about the time of day in the 1950s.
+ (Thanks to John Seigenthaler.)
+
+ Liechtenstein observed Swiss DST in 1941/2.
+ (Thanks to Alois Treindl.)
+
+
Release 2019b - 2019-07-01 00:09:53 -0700
Briefly:
Brazil no longer observes DST.
'zic -b slim' outputs smaller TZif files; please try it out.
Palestine's 2019 spring-forward transition was on 03-29, not 03-30.
Changes to future timestamps
Brazil has canceled DST and will stay on standard time indefinitely.
(Thanks to Steffen Thorsen, Marcus Diniz, and Daniel Soares de
Oliveira.)
Predictions for Morocco now go through 2087 instead of 2037, to
work around a problem on newlib when using TZif files output by
zic 2019a or earlier. (Problem reported by David Gauchard.)
Changes to past and future timestamps
Palestine's 2019 spring transition was 03-29 at 00:00, not 03-30
at 01:00. (Thanks to Sharef Mustafa and Even Scharning.) Guess
future transitions to be March's last Friday at 00:00.
Changes to past timestamps
Hong Kong's 1941-06-15 spring-forward transition was at 03:00, not
03:30. Its 1945 transition from JST to HKT was on 11-18 at 02:00,
not 09-15 at 00:00. In 1946 its spring-forward transition was on
04-21 at 00:00, not the previous day at 03:30. From 1946 through
1952 its fall-back transitions occurred at 04:30, not at 03:30.
In 1947 its fall-back transition was on 11-30, not 12-30.
(Thanks to P Chan.)
Changes to past time zone abbreviations
Italy's 1866 transition to Rome Mean Time was on December 12, not
September 22. This affects only the time zone abbreviation for
Europe/Rome between those dates. (Thanks to Stephen Trainor and
Luigi Rosa.)
Changes affecting metadata only
Add info about the Crimea situation in zone1970.tab and zone.tab.
(Problem reported by Serhii Demediuk.)
Changes to code
zic's new -b option supports a way to control data bloat and to
test for year-2038 bugs in software that reads TZif files.
'zic -b fat' and 'zic -b slim' generate larger and smaller output;
for example, changing from fat to slim shrinks the Europe/London
file from 3648 to 1599 bytes, saving about 56%. Fat and slim
files represent the same set of timestamps and use the same TZif
format as documented in tzfile(5) and in Internet RFC 8536.
Fat format attempts to work around bugs or incompatibilities in
older software, notably software that mishandles 64-bit TZif data
or uses obsolete TZ strings like "EET-2EEST" that lack DST rules.
Slim format is more efficient and does not work around 64-bit bugs
or obsolete TZ strings. Currently zic defaults to fat format
unless you compile with -DZIC_BLOAT_DEFAULT=\"slim\"; this
out-of-the-box default is intended to change in future releases
as the buggy software often mishandles timestamps anyway.
zic no longer treats a set of rules ending in 2037 specially.
Previously, zic assumed that such a ruleset meant that future
timestamps could not be predicted, and therefore omitted a
POSIX-like TZ string in the TZif output. The old behavior is no
longer needed for current tzdata, and caused problems with newlib
when used with older tzdata (reported by David Gauchard).
zic no longer generates some artifact transitions. For example,
Europe/London no longer has a no-op transition in January 1996.
Changes to build procedure
tzdata.zi now assumes zic 2017c or later. This shrinks tzdata.zi
by a percent or so.
Changes to documentation and commentary
The Makefile now documents the POSIXRULES macro as being obsolete,
and similarly, zic's -p POSIXRULES option is now documented as
being obsolete. Although the POSIXRULES feature still exists and
works as before, in practice it is rarely used for its intended
purpose, and it does not work either in the default reference
implementation (for timestamps after 2037) or in common
implementations such as GNU/Linux (for contemporary timestamps).
Since POSIXRULES was designed primarily as a temporary transition
facility for System V platforms that died off decades ago, it is
being decommissioned rather than institutionalized.
New info on Bonin Islands and Marcus (thanks to Wakaba and Phake Nick).
Release 2019a - 2019-03-25 22:01:33 -0700
Briefly:
Palestine "springs forward" on 2019-03-30 instead of 2019-03-23.
Metlakatla "fell back" to rejoin Alaska Time on 2019-01-20 at 02:00.
Changes to past and future timestamps
Palestine will not start DST until 2019-03-30, instead of 2019-03-23 as
previously predicted. Adjust our prediction by guessing that spring
transitions will be between 24 and 30 March, which matches recent practice
since 2016. (Thanks to Even Scharning and Tim Parenti.)
Metlakatla ended its observance of Pacific standard time,
rejoining Alaska Time, on 2019-01-20 at 02:00. (Thanks to Ryan
Stanley and Tim Parenti.)
Changes to past timestamps
Israel observed DST in 1980 (08-02/09-13) and 1984 (05-05/08-25).
(Thanks to Alois Treindl and Isaac Starkman.)
Changes to time zone abbreviations
Etc/UCT is now a backward-compatibility link to Etc/UTC, instead
of being a separate zone that generates the abbreviation "UCT",
which nowadays is typically a typo. (Problem reported by Isiah
Meadows.)
Changes to code
zic now has an -r option to limit the time range of output data.
For example, 'zic -r @1000000000' limits the output data to
timestamps starting 1000000000 seconds after the Epoch.
This helps shrink output size and can be useful for applications
not needing the full timestamp history, such as TZDIST truncation;
see Internet RFC 8536 section 5.1. (Inspired by a feature request
from Christopher Wong, helped along by bug reports from Wong and
from Tim Parenti.)
Changes to documentation
Mention Internet RFC 8536 (February 2019), which documents TZif.
tz-link.html now cites tzdata-meta
<https://tzdata-meta.timtimeonline.com/>.
Release 2018i - 2018-12-30 11:05:43 -0800
Briefly:
São Tomé and Príncipe switches from +01 to +00 on 2019-01-01.
Changes to future timestamps
Due to a change in government, São Tomé and Príncipe switches back
from +01 to +00 on 2019-01-01 at 02:00. (Thanks to Vadim
Nasardinov and Michael Deckers.)
Release 2018h - 2018-12-23 17:59:32 -0800
Briefly:
Qyzylorda, Kazakhstan moved from +06 to +05 on 2018-12-21.
New zone Asia/Qostanay because Qostanay, Kazakhstan didn't move.
Metlakatla, Alaska observes PST this winter only.
Guess Morocco will continue to adjust clocks around Ramadan.
Add predictions for Iran from 2038 through 2090.
Changes to future timestamps
Guess that Morocco will continue to fall back just before and
spring forward just after Ramadan, the practice since 2012.
(Thanks to Maamar Abdelkader.) This means Morocco will observe
negative DST during Ramadan in main and vanguard formats, and in
rearguard format it stays in the +00 timezone and observes
ordinary DST in all months other than Ramadan. As before, extend
this guesswork to the year 2037. As a consequence, Morocco is
scheduled to observe three DST transitions in some Gregorian years
(e.g., 2033) due to the mismatch between the Gregorian and Islamic
calendars.
The table of exact transitions for Iranian DST has been extended.
It formerly cut off before the year 2038 in a nod to 32-bit time_t.
It now cuts off before 2091 as there is doubt about how the Persian
calendar will treat 2091. This change predicts DST transitions in
2038-9, 2042-3, and 2046-7 to occur one day later than previously
predicted. As before, post-cutoff transitions are approximated.
Changes to past and future timestamps
Qyzylorda (aka Kyzylorda) oblast in Kazakhstan moved from +06 to
+05 on 2018-12-21. This is a zone split as Qostanay (aka
Kostanay) did not switch, so create a zone Asia/Qostanay.
Metlakatla moved from Alaska to Pacific standard time on 2018-11-04.
It did not change clocks that day and remains on -08 this winter.
(Thanks to Ryan Stanley.) It will revert to the usual Alaska
rules next spring, so this change affects only timestamps
from 2018-11-04 through 2019-03-10.
Change to past timestamps
Kwajalein's 1993-08-20 transition from -12 to +12 was at 24:00,
not 00:00. I transcribed the time incorrectly from Shanks.
(Thanks to Phake Nick.)
Nauru's 1979 transition was on 02-10 at 02:00, not 05-01 at 00:00.
(Thanks to Phake Nick.)
Guam observed DST irregularly from 1959 through 1977.
(Thanks to Phake Nick.)
Hong Kong observed DST in 1941 starting 06-15 (not 04-01), then on
10-01 changed standard time to +08:30 (not +08). Its transition
back to +08 after WWII was on 1945-09-15, not the previous day.
Its 1904-10-30 change took effect at 01:00 +08 (not 00:00 LMT).
(Thanks to Phake Nick, Steve Allen, and Joseph Myers.) Also,
its 1952 fallback was on 11-02 (not 10-25).
This release contains many changes to timestamps before 1946 due
to Japanese possession or occupation of Pacific/Chuuk,
Pacific/Guam, Pacific/Kosrae, Pacific/Kwajalein, Pacific/Majuro,
Pacific/Nauru, Pacific/Palau, and Pacific/Pohnpei.
(Thanks to Phake Nick.)
Assume that the Spanish East Indies was like the Philippines and
observed American time until the end of 1844. This affects
Pacific/Chuuk, Pacific/Kosrae, Pacific/Palau, and Pacific/Pohnpei.
Changes to past tm_isdst flags
For the recent Morocco change, the tm_isdst flag should be 1 from
2018-10-27 00:00 to 2018-10-28 03:00. (Thanks to Michael Deckers.)
Give a URL to the official decree. (Thanks to Matt Johnson.)
Release 2018g - 2018-10-26 22:22:45 -0700
Briefly:
Morocco switches to permanent +01 on 2018-10-28.
Changes to future timestamps
Morocco switches from +00/+01 to permanent +01 effective 2018-10-28,
so its clocks will not fall back as previously scheduled.
(Thanks to Mohamed Essedik Najd and Brian Inglis.)
Changes to code
When generating TZif files with leap seconds, zic no longer uses a
format that trips up older 32-bit clients, fixing a bug introduced
in 2018f. (Reported by Daniel Fischer.) Also, the zic workaround
for QTBUG-53071 now also works for TZif files with leap seconds.
The translator to rearguard format now rewrites the line
"Rule Japan 1948 1951 - Sep Sat>=8 25:00 0 S" to
"Rule Japan 1948 1951 - Sep Sun>=9 1:00 0 S".
This caters to zic before 2007 and to Oracle TZUpdater 2.2.0
and earlier. (Reported by Christos Zoulas.)
Changes to past time zone abbreviations
Change HDT to HWT/HPT for WWII-era abbreviations in Hawaii.
This reverts to 2011h, as the abbreviation change in 2011i was
likely inadvertent.
Changes to documentation
tzfile.5 has new sections on interoperability issues.
Release 2018f - 2018-10-18 00:14:18 -0700
Briefly:
Volgograd moves from +03 to +04 on 2018-10-28.
Fiji ends DST 2019-01-13, not 2019-01-20.
Most of Chile changes DST dates, effective 2019-04-06.
Changes to future timestamps
Volgograd moves from +03 to +04 on 2018-10-28 at 02:00.
(Thanks to Alexander Fetisov and Stepan Golosunov.)
Fiji ends DST 2019-01-13 instead of the 2019-01-20 previously
predicted. (Thanks to Raymond Kumar.) Adjust future predictions
accordingly.
Most of Chile will end DST on the first Saturday in April at 24:00 mainland
time, and resume DST on the first Saturday in September at 24:00 mainland
time. The changes are effective from 2019-04-06, and do not affect the
Magallanes region modeled by America/Punta_Arenas. (Thanks to Juan Correa
and Tim Parenti.) Adjust future predictions accordingly.
Changes to past timestamps
The 2018-05-05 North Korea 30-minute time zone change took place
at 23:30 the previous day, not at 00:00 that day.
China's 1988 spring-forward transition was on April 17, not
April 10. Its DST transitions in 1986/91 were at 02:00, not 00:00.
(Thanks to P Chan.)
Fix several issues for Macau before 1992. Macau's pre-1904 LMT
was off by 10 s. Macau switched to +08 in 1904 not 1912, and
temporarily switched to +09/+10 during World War II. Macau
observed DST in 1942/79, not 1961/80, and there were several
errors for transition times and dates. (Thanks to P Chan.)
The 1948-1951 fallback transitions in Japan were at 25:00 on
September's second Saturday, not at 24:00. (Thanks to Phake Nick.)
zic turns this into 01:00 on the day after September's second
Saturday, which is the best that POSIX or C platforms can do.
Incorporate 1940-1949 Asia/Shanghai DST transitions from a 2014
paper by Li Yu, replacing more-questionable data from Shanks.
Changes to time zone abbreviations
Use "PST" and "PDT" for Philippine time. (Thanks to Paul Goyette.)
Changes to code
zic now always generates TZif files where time type 0 is used for
timestamps before the first transition. This simplifies the
reading of TZif files and should not affect behavior of existing
TZif readers because the same set of time types is used; only
their internal indexes may have changed. This affects only the
legacy zones EST5EDT, CST6CDT, MST7MDT, PST8PDT, CET, MET, and
EET, which previously used nonzero types for these timestamps.
Because of the type 0 change, zic no longer outputs a dummy
transition at time -2**59 (before the Big Bang), as clients should
no longer need this to handle historical timestamps correctly.
This reverts a change introduced in 2013d and shrinks most TZif
files by a few bytes.
zic now supports negative time-of-day in Rule and Leap lines, e.g.,
"Rule X min max - Apr lastSun -6:00 1:00 -" means the transition
occurs at 18:00 on the Saturday before the last Sunday in April.
This behavior was documented in 2018a but the code did not
entirely match the documentation.
localtime.c no longer requires at least one time type in TZif
files that lack transitions or have a POSIX-style TZ string. This
future-proofs the code against possible future extensions to the
format that would allow TZif files with POSIX-style TZ strings and
without transitions or time types.
A read-access subscript error in localtime.c has been fixed.
It could occur only in TZif files with timecnt == 0, something that
does not happen in practice now but could happen in future versions.
localtime.c no longer ignores TZif POSIX-style TZ strings that
specify only standard time. Instead, these TZ strings now
override the default time type for timestamps after the last
transition (or for all timestamps if there are no transitions),
just as DST strings specifying DST have always done.
leapseconds.awk now outputs "#updated" and "#expires" comments,
and supports leap seconds at the ends of months other than June
and December. (Inspired by suggestions from Chris Woodbury.)
Changes to documentation
New restrictions: A Rule name must start with a character that
is neither an ASCII digit nor "-" nor "+", and an unquoted name
should not use characters in the set "!$%&'()*,/:;<=>?@[\]^`{|}~".
The latter restriction makes room for future extensions (a
possibility noted by Tom Lane).
tzfile.5 now documents what time types apply before the first and
after the last transition, if any.
Documentation now uses the spelling "timezone" for a TZ setting
that determines timestamp history, and "time zone" for a
geographic region currently sharing the same standard time.
The name "TZif" is now used for the tz binary data format.
tz-link.htm now mentions the A0 TimeZone Migration utilities.
(Thanks to Aldrin Martoq for the link.)
Changes to build procedure
New 'make' target 'rearguard_tarballs' to build the rearguard
tarball only. This is a convenience on platforms that lack lzip
if you want to build the rearguard tarball. (Problem reported by
Deborah Goldsmith.)
tzdata.zi is now more stable from release to release. (Problem
noted by Tom Lane.) It is also a bit shorter.
tzdata.zi now can contain comment lines documenting configuration
information, such as which data format was selected, which input
files were used, and how leap seconds are treated. (Problems
noted by Lester Caine and Brian Inglis.) If the Makefile defaults
are used these comment lines are absent, for backward
compatibility. A redistributor intending to alter its copy of the
files should also append "-LABEL" to the 'version' file's first
line, where "LABEL" identifies the redistributor's change.
Release 2018e - 2018-05-01 23:42:51 -0700
Briefly:
North Korea switches back to +09 on 2018-05-05.
The main format uses negative DST again, for Ireland etc.
'make tarballs' now also builds a rearguard tarball.
New 's' and 'd' suffixes in SAVE columns of Rule and Zone lines.
Changes to past and future timestamps
North Korea switches back from +0830 to +09 on 2018-05-05.
(Thanks to Kang Seonghoon, Arthur David Olson, Seo Sanghyeon,
and Tim Parenti.)
Bring back the negative-DST changes of 2018a, except be more
compatible with data parsers that do not support negative DST.
Also, this now affects historical timestamps in Namibia and the
former Czechoslovakia, not just Ireland. The main format now uses
negative DST to model timestamps in Europe/Dublin (from 1971 on),
Europe/Prague (1946/7), and Africa/Windhoek (1994/2017). This
does not affect UT offsets, only time zone abbreviations and the
tm_isdst flag. Also, this does not affect rearguard or vanguard
formats; effectively the main format now uses vanguard instead of
rearguard format. Data parsers that do not support negative DST
can still use data from the rearguard tarball described below.
Changes to build procedure
The command 'make tarballs' now also builds the tarball
tzdataVERSION-rearguard.tar.gz, which is like tzdataVERSION.tar.gz
except that it uses rearguard format intended for trailing-edge
data parsers.
Changes to data format and to code
The SAVE column of Rule and Zone lines can now have an 's' or 'd'
suffix, which specifies whether the adjusted time is standard time
or daylight saving time. If no suffix is given, daylight saving
time is used if and only if the SAVE column is nonzero; this is
the longstanding behavior. Although this new feature is not used
in tzdata, it could be used to specify the legal time in Namibia
1994-2017, as opposed to the popular time (see below).
Changes to past timestamps
From 1994 through 2017 Namibia observed DST in winter, not summer.
That is, it used negative DST, as Ireland still does. This change
does not affect UTC offsets; it affects only the tm_isdst flag and
the abbreviation used during summer, which is now CAT, not WAST.
Although (as noted by Michael Deckers) summer and winter time were
both simply called "standard time" in Namibian law, in common
practice winter time was considered to be DST (as noted by Stephen
Colebourne). The full effect of this change is only in vanguard
and main format; in rearguard format, the tm_isdst flag is still
zero in winter and nonzero in summer.
In 1946/7 Czechoslovakia also observed negative DST in winter.
The full effect of this change is only in vanguard and main
formats; in rearguard format, it is modeled as plain GMT without
daylight saving. Also, the dates of some 1944/5 DST transitions
in Czechoslovakia have been changed.
Release 2018d - 2018-03-22 07:05:46 -0700
Briefly:
Palestine starts DST a week earlier in 2018.
Add support for vanguard and rearguard data consumers.
Add subsecond precision to source data format, though not to data.
Changes to future timestamps
In 2018, Palestine starts DST on March 24, not March 31.
Adjust future predictions accordingly. (Thanks to Sharef Mustafa.)
Changes to past and future timestamps
Casey Station in Antarctica changed from +11 to +08 on 2018-03-11
at 04:00. (Thanks to Steffen Thorsen.)
Changes to past timestamps
Historical transitions for Uruguay, represented by
America/Montevideo, have been updated per official legal documents,
replacing previous data mainly originating from the inventions of
Shanks & Pottenger. This has resulted in adjustments ranging from
30 to 90 minutes in either direction over at least two dozen
distinct periods ranging from one day to several years in length.
A mere handful of pre-1991 transitions are unaffected; data since
then has come from more reliable contemporaneous reporting. These
changes affect various timestamps in 1920-1923, 1936, 1939,
1942-1943, 1959, 1966-1970, 1972, 1974-1980, and 1988-1990.
Additionally, Uruguay's pre-standard-time UT offset has been
adjusted westward by 7 seconds, from UT-03:44:44 to UT-03:44:51, to
match the location of the Observatory of the National Meteorological
Institute in Montevideo.
(Thanks to Jeremie Bonjour, Tim Parenti, and Michael Deckers.)
Enderbury and Kiritimati skipped New Year's Eve 1994, not
New Year's Day 1995. (Thanks to Kerry Shetline.)
Fix the 1912-01-01 transition for Portugal and its colonies.
This transition was at 00:00 according to the new UT offset, not
according to the old one. Also assume that Cape Verde switched on
the same date as the rest, not in 1907. This affects
Africa/Bissau, Africa/Sao_Tome, Asia/Macau, Atlantic/Azores,
Atlantic/Cape_Verde, Atlantic/Madeira, and Europe/Lisbon.
(Thanks to Michael Deckers.)
Fix an off-by-1 error for pre-1913 timestamps in Jamaica and in
Turks & Caicos.
Changes to past time zone abbreviations
MMT took effect in Uruguay from 1908-06-10, not 1898-06-28. There
is no clock change associated with the transition.
Changes to build procedure
The new DATAFORM macro in the Makefile lets the installer choose
among three source data formats. The idea is to lessen downstream
disruption when data formats are improved.
* DATAFORM=vanguard installs from the latest, bleeding-edge
format. DATAFORM=main (the default) installs from the format
used in the 'africa' etc. files. DATAFORM=rearguard installs
from a trailing-edge format. Eventually, elements of today's
vanguard format should move to the main format, and similarly
the main format's features should eventually move to the
rearguard format.
* In the current version, the main and rearguard formats are
identical and match that of 2018c, so this change does not
affect default behavior. The vanguard format currently contains
one feature not in the main format: negative SAVE values. This
improves support for Ireland, which uses Irish Standard Time
(IST, UTC+01) in summer and GMT (UTC) in winter. tzcode has
supported negative SAVE values for decades, and this feature
should move to the main format soon. However, it will not move
to the rearguard format for quite some time because some
downstream parsers do not support it.
* The build procedure constructs three files vanguard.zi, main.zi,
and rearguard.zi, one for each format. Although the files
represent essentially the same data, they may have minor
discrepancies that users are not likely to notice. The files
are intended for downstream data consumers and are not
installed. Zoneinfo parsers that do not support negative SAVE values
should start using rearguard.zi, so that they will be unaffected
when the negative-DST feature moves from vanguard to main.
Bleeding-edge Zoneinfo parsers that support the new features
already can use vanguard.zi; in this respect, current tzcode is
bleeding-edge.
The Makefile should now be safe for parallelized builds, and 'make
-j to2050new.tzs' is now much faster on a multiprocessor host
with GNU Make.
When built with -DSUPPRESS_TZDIR, the tzcode library no longer
prepends TZDIR/ to file names that do not begin with '/'. This is
not recommended for general use, due to its security implications.
(From a suggestion by Manuela Friedrich.)
Changes to code
zic now accepts subsecond precision in expressions like
00:19:32.13, which is approximately the legal time of the
Netherlands from 1835 to 1937. However, because it is
questionable whether the few recorded uses of non-integer offsets
had subsecond precision in practice, there are no plans for tzdata
to use this feature. (Thanks to Steve Allen for pointing out
the limitations of historical data in this area.)
The code is a bit more portable to MS-Windows. Installers can
compile with -DRESERVE_STD_EXT_IDS on MS-Windows platforms that
reserve identifiers like 'localtime'. (Thanks to Manuela
Friedrich.)
Changes to documentation and commentary
theory.html now outlines tzdb's extensions to POSIX's model for
civil time, and has a section "POSIX features no longer needed"
that lists POSIX API components that are now vestigial.
(From suggestions by Steve Summit.) It also better distinguishes
time zones from tz regions. (From a suggestion by Guy Harris.)
Commentary is now more consistent about using the phrase "daylight
saving time", to match the C name tm_isdst. Daylight saving time
need not occur in summer, and need not have a positive offset from
standard time.
Commentary about historical transitions in Uruguay has been expanded
with links to many relevant legal documents.
(Thanks to Tim Parenti.)
Commentary now uses some non-ASCII characters with Unicode value
less than U+0100, as they can be useful and should work even with
older editors such as XEmacs.
Release 2018c - 2018-01-22 23:00:44 -0800
Briefly:
Revert Irish changes that relied on negative SAVE values.
Changes to tm_isdst
Revert the 2018a change to Europe/Dublin. As before, this change
does not affect UT offsets or abbreviations; it affects only
whether timestamps are considered to be standard time or
daylight-saving time, as expressed in the tm_isdst flag of C's
struct tm type. This reversion is intended to be a temporary
workaround for problems discovered with downstream uses of
releases 2018a and 2018b, which implemented Irish time by using
negative SAVE values in the Eire rules of the 'europe' file.
Although negative SAVE values have been part of tzcode for many
years and are supported by many platforms, they were not
documented before 2018a and ICU and OpenJDK do not currently
support them. A mechanism to export data to platforms lacking
support for negative DST is planned to be developed before the
change is reapplied. (Problems reported by Deborah Goldsmith and
Stephen Colebourne.)
Changes to past timestamps
Japanese DST transitions (1948-1951) were Sundays at 00:00, not
Saturdays or Sundays at 02:00. (Thanks to Takayuki Nikai.)
Changes to build procedure
The build procedure now works around mawk 1.3.3's lack of support
for character class expressions. (Problem reported by Ohyama.)
Release 2018b - 2018-01-17 23:24:48 -0800
Briefly:
Fix a packaging problem in tz2018a, which was missing 'pacificnew'.
Changes to build procedure
The distribution now contains the file 'pacificnew' again.
This file was inadvertantly omitted in the 2018a distribution.
(Problem reported by Matias Fonzo.)
Release 2018a - 2018-01-12 22:29:21 -0800
Briefly:
São Tomé and Príncipe switched from +00 to +01.
Brazil's DST will now start on November's first Sunday.
Ireland's standard time is now in the summer, not the winter.
Use Debian-style installation locations, instead of 4.3BSD-style.
New zic option -t.
Changes to past and future timestamps
São Tomé and Príncipe switched from +00 to +01 on 2018-01-01 at
01:00. (Thanks to Steffen Thorsen and Michael Deckers.)
Changes to future timestamps
Starting in 2018 southern Brazil will begin DST on November's
first Sunday instead of October's third Sunday. (Thanks to
Steffen Thorsen.)
Changes to past timestamps
A discrepancy of 4 s in timestamps before 1931 in South Sudan has
been corrected. The 'backzone' and 'zone.tab' files did not agree
with the 'africa' and 'zone1970.tab' files. (Problem reported by
Michael Deckers.)
The abbreviation invented for Bolivia Summer Time (1931-2) is now
BST instead of BOST, to be more consistent with the convention
used for Latvian Summer Time (1918-9) and for British Summer Time.
Changes to tm_isdst
Change Europe/Dublin so that it observes Irish Standard Time (UT
+01) in summer and GMT (as negative daylight-saving) in winter,
instead of observing standard time (GMT) in winter and Irish
Summer Time (UT +01) in summer. This change does not affect UT
offsets or abbreviations; it affects only whether timestamps are
considered to be standard time or daylight-saving time, as
expressed in the tm_isdst flag of C's struct tm type.
(Discrepancy noted by Derick Rethans.)
Changes to build procedure
The default installation locations have been changed to mostly
match Debian circa 2017, instead of being designed as an add-on to
4.3BSD circa 1986. This affects the Makefile macros TOPDIR,
TZDIR, MANDIR, and LIBDIR. New Makefile macros TZDEFAULT, USRDIR,
USRSHAREDIR, BINDIR, ZDUMPDIR, and ZICDIR let installers tailor
locations more precisely. (This responds to suggestions from
Brian Inglis and from Steve Summit.)
The default installation procedure no longer creates the
backward-compatibility link US/Pacific-New, which causes
confusion during user setup (e.g., see Debian bug 815200).
Use 'make BACKWARD="backward pacificnew"' to create the link
anyway, for now. Eventually we plan to remove the link entirely.
tzdata.zi now contains a version-number comment.
(Suggested by Tom Lane.)
The Makefile now quotes values like BACKWARD more carefully when
passing them to the shell. (Problem reported by Zefram.)
Builders no longer need to specify -DHAVE_SNPRINTF on platforms
that have snprintf and use pre-C99 compilers. (Problem reported
by Jon Skeet.)
Changes to code
zic has a new option -t FILE that specifies the location of the
file that determines local time when TZ is unset. The default for
this location can be configured via the new TZDEFAULT makefile
macro, which defaults to /etc/localtime.
Diagnostics and commentary now distinguish UT from UTC more
carefully; see theory.html for more information about UT vs UTC.
zic has been ported to GCC 8's -Wstringop-truncation option.
(Problem reported by Martin Sebor.)
Changes to documentation and commentary
The zic man page now documents the longstanding behavior that
times and years can be out of the usual range, with negative times
counting backwards from midnight and with year 0 preceding year 1.
(Problem reported by Michael Deckers.)
The theory.html file now mentions the POSIX limit of six chars
per abbreviation, and lists alphabetic abbreviations used.
The files tz-art.htm and tz-link.htm have been renamed to
tz-art.html and tz-link.html, respectively, for consistency with
other file names and to simplify web server configuration.
Release 2017c - 2017-10-20 14:49:34 -0700
Briefly:
Northern Cyprus switches from +03 to +02/+03 on 2017-10-29.
Fiji ends DST 2018-01-14, not 2018-01-21.
Namibia switches from +01/+02 to +02 on 2018-04-01.
Sudan switches from +03 to +02 on 2017-11-01.
Tonga likely switches from +13/+14 to +13 on 2017-11-05.
Turks & Caicos switches from -04 to -05/-04 on 2018-11-04.
A new file tzdata.zi now holds a small text copy of all data.
The zic input format has been regularized slightly.
Changes to future timestamps
Northern Cyprus has decided to resume EU rules starting
2017-10-29, thus reinstituting winter time.
Fiji ends DST 2018-01-14 instead of the 2018-01-21 previously
predicted. (Thanks to Dominic Fok.) Adjust future predictions
accordingly.
Namibia will switch from +01 with DST to +02 all year on
2017-09-03 at 02:00. This affects UT offsets starting 2018-04-01
at 02:00. (Thanks to Steffen Thorsen.)
Sudan will switch from +03 to +02 on 2017-11-01. (Thanks to Ahmed
Atyya and Yahia Abdalla.) South Sudan is not switching, so
Africa/Juba is no longer a link to Africa/Khartoum.
Tonga has likely ended its experiment with DST, and will not
adjust its clocks on 2017-11-05. Although Tonga has not announced
whether it will continue to observe DST, the IATA is assuming that
it will not. (Thanks to David Wade.)
Turks & Caicos will switch from -04 all year to -05 with US DST on
2018-03-11 at 03:00. This affects UT offsets starting 2018-11-04
at 02:00. (Thanks to Steffen Thorsen.)
Changes to past timestamps
Namibia switched from +02 to +01 on 1994-03-21, not 1994-04-03.
(Thanks to Arthur David Olson.)
Detroit did not observe DST in 1967.
Use railway time for Asia/Kolkata before 1941, by switching to
Madras local time (UT +052110) in 1870, then to IST (UT +0530) in
1906. Also, treat 1941-2's +0630 as DST, like 1942-5.
Europe/Dublin's 1946 and 1947 fallback transitions occurred at
02:00 standard time, not 02:00 DST. (Thanks to Michael Deckers.)
Pacific/Apia and Pacific/Pago_Pago switched from Antipodean to
American time in 1892, not 1879. (Thanks to Michael Deckers.)
Adjust the 1867 transition in Alaska to better reflect the
historical record, by changing it to occur on 1867-10-18 at 15:30
Sitka time rather than at the start of 1867-10-17 local time.
Although strictly speaking this is accurate only for Sitka,
the rest of Alaska's blanks need to be filled in somehow.
Fix off-by-one errors in UT offsets for Adak and Nome before 1867.
(Thanks to Michael Deckers.)
Add 7 s to the UT offset in Asia/Yangon before 1920.
Changes to zone names
Remove Canada/East-Saskatchewan from the 'backward' file, as it
exceeded the 14-character limit and was an unused misnomer anyway.
Changes to build procedure
To support applications that prefer to read time zone data in text
form, two zic input files tzdata.zi and leapseconds are now
installed by default. The commands 'zic tzdata.zi' and 'zic -L
leapseconds tzdata.zi' can reproduce the tzdata binary files
without and with leap seconds, respectively. To prevent these two
new files from being installed, use 'make TZDATA_TEXT=', and to
suppress leap seconds from the tzdata text installation, use 'make
TZDATA_TEXT=tzdata.zi'.
'make BACKWARD=' now suppresses backward-compatibility names
like 'US/Pacific' that are defined in the 'backward' and
'pacificnew' files.
'make check' now works on systems that lack a UTF-8 locale,
or that lack the nsgmls program. Set UTF8_LOCALE to configure
the name of a UTF-8 locale, if you have one.
Y2K runtime checks are no longer enabled by default. Add
-DDEPRECATE_TWO_DIGIT_YEARS to CFLAGS to enable them, instead of
adding -DNO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU
to disable them. (New name suggested by Brian Inglis.)
The build procedure for zdump now works on AIX 7.1.
(Problem reported by Kees Dekker.)
Changes to code
zic and the reference runtime now reject multiple leap seconds
within 28 days of each other, or leap seconds before the Epoch.
As a result, support for double leap seconds, which was
obsolescent and undocumented, has been removed. Double leap
seconds were an error in the C89 standard; they have never existed
in civil timekeeping. (Thanks to Robert Elz and Bradley White for
noticing glitches in the code that uncovered this problem.)
zic now warns about use of the obsolescent and undocumented -y
option, and about use of the obsolescent TYPE field of Rule lines.
zic now allows unambiguous abbreviations like "Sa" and "Su" for
weekdays; formerly it rejected them due to a bug. Conversely, zic
no longer considers non-prefixes to be abbreviations; for example,
it no longer accepts "lF" as an abbreviation for "lastFriday".
Also, zic warns about the undocumented usage with a "last-"
prefix, e.g., "last-Fri".
Similarly, zic now accepts the unambiguous abbreviation "L" for
"Link" in ordinary context and for "Leap" in leap-second context.
Conversely, zic no longer accepts non-prefixes such as "La" as
abbreviations for words like "Leap".
zic no longer accepts leap second lines in ordinary input, or
ordinary lines in leap second input. Formerly, zic sometimes
warned about this undocumented usage and handled it incorrectly.
The new macro HAVE_TZNAME governs whether the tzname external
variable is exported, instead of USG_COMPAT. USG_COMPAT now
governs only the external variables "timezone" and "daylight".
This change is needed because the three variables are not in the
same category: although POSIX requires tzname, it specifies the
other two variables as optional. Also, USG_COMPAT is now 1 or 0:
if not defined, the code attempts to guess it from other macros.
localtime.c and difftime.c no longer require stdio.h, and .c files
other than zic.c no longer require sys/wait.h.
zdump.c no longer assumes snprintf. (Reported by Jonathan Leffler.)
Calculation of time_t extrema works around a bug in GCC 4.8.4
(Reported by Stan Shebs and Joseph Myers.)
zic.c no longer mistranslates formats of line numbers in non-English
locales. (Problem reported by Benno Schulenberg.)
Several minor changes have been made to the code to make it a
bit easier to port to MS-Windows and Solaris. (Thanks to Kees
Dekker for reporting the problems.)
Changes to documentation and commentary
The two new files 'theory.html' and 'calendars' contain the
contents of the removed file 'Theory'. The goal is to document
tzdb theory more accessibly.
The zic man page now documents abbreviation rules.
tz-link.htm now covers how to apply tzdata changes to clients.
(Thanks to Jorge Fábregas for the AIX link.) It also mentions MySQL.
The leap-seconds.list URL has been updated to something that is
more reliable for tzdb. (Thanks to Tim Parenti and Brian Inglis.)
Release 2017b - 2017-03-17 07:30:38 -0700
Briefly: Haiti has resumed DST.
Changes to past and future timestamps
Haiti resumed observance of DST in 2017. (Thanks to Steffen Thorsen.)
Changes to past timestamps
Liberia changed from -004430 to +00 on 1972-01-07, not 1972-05-01.
Use "MMT" to abbreviate Liberia's time zone before 1972, as "-004430"
is one byte over the POSIX limit. (Problem reported by Derick Rethans.)
Changes to code
The reference localtime implementation now falls back on the
current US daylight-saving transition rules rather than the
1987-2006 rules. This fallback occurs only when (1) the TZ
environment variable has a value like "AST4ADT" that asks
for daylight saving time but does not specify the rules, (2) there
is no file by that name, and (3) the TZDEFRULES file cannot be
loaded. (Thanks to Tom Lane.)
Release 2017a - 2017-02-28 00:05:36 -0800
Briefly: Southern Chile moves from -04/-03 to -03, and Mongolia
discontinues DST.
Changes to future timestamps
Mongolia no longer observes DST. (Thanks to Ganbold Tsagaankhuu.)
Chile's Region of Magallanes moves from -04/-03 to -03 year-round.
Its clocks diverge from America/Santiago starting 2017-05-13 at
23:00, hiving off a new zone America/Punta_Arenas. Although the
Chilean government says this change expires in May 2019, for now
assume it's permanent. (Thanks to Juan Correa and Deborah
Goldsmith.) This also affects Antarctica/Palmer.
Changes to past timestamps
Fix many entries for historical timestamps for Europe/Madrid
before 1979, to agree with tables compiled by Pere Planesas of the
National Astronomical Observatory of Spain. As a side effect,
this changes some timestamps for Africa/Ceuta before 1929, which
are probably guesswork anyway. (Thanks to Steve Allen and
Pierpaolo Bernardi for the heads-ups, and to Michael Deckers for
correcting the 1901 transition.)
Ecuador observed DST from 1992-11-28 to 1993-02-05.
(Thanks to Alois Treindl.)
Asia/Atyrau and Asia/Oral were at +03 (not +04) before 1930-06-21.
(Thanks to Stepan Golosunov.)
Changes to past and future time zone abbreviations
Switch to numeric time zone abbreviations for South America, as
part of the ongoing project of removing invented abbreviations.
This avoids the need to invent an abbreviation for the new Chilean
new zone. Similarly, switch from invented to numeric time zone
abbreviations for Afghanistan, American Samoa, the Azores,
Bangladesh, Bhutan, the British Indian Ocean Territory, Brunei,
Cape Verde, Chatham Is, Christmas I, Cocos (Keeling) Is, Cook Is,
Dubai, East Timor, Eucla, Fiji, French Polynesia, Greenland,
Indochina, Iran, Iraq, Kiribati, Lord Howe, Macquarie, Malaysia,
the Maldives, Marshall Is, Mauritius, Micronesia, Mongolia,
Myanmar, Nauru, Nepal, New Caledonia, Niue, Norfolk I, Palau,
Papua New Guinea, the Philippines, Pitcairn, Qatar, Réunion, St
Pierre & Miquelon, Samoa, Saudi Arabia, Seychelles, Singapore,
Solomon Is, Tokelau, Tuvalu, Wake, Vanuatu, Wallis & Futuna, and
Xinjiang; for 20-minute daylight saving time in Ghana before 1943;
for half-hour daylight saving time in Belize before 1944 and in
the Dominican Republic before 1975; and for Canary Islands before
1946, for Guinea-Bissau before 1975, for Iceland before 1969, for
Indian Summer Time before 1942, for Indonesia before around 1964,
for Kenya before 1960, for Liberia before 1973, for Madeira before
1967, for Namibia before 1943, for the Netherlands in 1937-9, for
Pakistan before 1971, for Western Sahara before 1977, and for
Zaporozhye in 1880-1924.
For Alaska time from 1900 through 1967, instead of "CAT" use the
abbreviation "AST", the abbreviation commonly used at the time
(Atlantic Standard Time had not been standardized yet). Use "AWT"
and "APT" instead of the invented abbreviations "CAWT" and "CAPT".
Use "CST" and "CDT" instead of invented abbreviations for Macau
before 1999 and Taiwan before 1938, and use "JST" instead of the
invented abbreviation "JCST" for Japan and Korea before 1938.
Change to database entry category
Move the Pacific/Johnston link from 'australasia' to 'backward',
since Johnston is now uninhabited.
Changes to code
zic no longer mishandles some transitions in January 2038 when it
attempts to work around Qt bug 53071. This fixes a bug affecting
Pacific/Tongatapu that was introduced in zic 2016e. localtime.c
now contains a workaround, useful when loading a file generated by
a buggy zic. (Problem and localtime.c fix reported by Bradley
White.)
zdump -i now outputs non-hour numeric time zone abbreviations
without a colon, e.g., "+0530" rather than "+05:30". This agrees
with zic %z and with common practice, and simplifies auditing of
zdump output.
zdump is now buildable again with -DUSE_LTZ=0.
(Problem reported by Joseph Myers.)
zdump.c now always includes private.h, to avoid code duplication
with private.h. (Problem reported by Kees Dekker.)
localtime.c no longer mishandles early or late timestamps
when TZ is set to a POSIX-style string that specifies DST.
(Problem reported by Kees Dekker.)
date and strftime now cause %z to generate "-0000" instead of
"+0000" when the UT offset is zero and the time zone abbreviation
begins with "-".
Changes to documentation and commentary
The 'Theory' file now better documents choice of historical time
zone abbreviations. (Problems reported by Michael Deckers.)
tz-link.htm now covers leap smearing, which is popular in clouds.
Release 2016j - 2016-11-22 23:17:13 -0800
Briefly: Saratov, Russia moves from +03 to +04 on 2016-12-04.
Changes to future timestamps
Saratov, Russia switches from +03 to +04 on 2016-12-04 at 02:00.
This hives off a new zone Europe/Saratov from Europe/Volgograd.
(Thanks to Yuri Konotopov and Stepan Golosunov.)
Changes to past timestamps
The new zone Asia/Atyrau for Atyraū Region, Kazakhstan, is like
Asia/Aqtau except it switched from +05/+06 to +04/+05 in spring
1999, not fall 1994. (Thanks to Stepan Golosunov.)
Changes to past time zone abbreviations
Asia/Gaza and Asia/Hebron now use "EEST", not "EET", to denote
summer time before 1948. The old use of "EET" was a typo.
Changes to code
zic no longer mishandles file systems that lack hard links, fixing
bugs introduced in 2016g. (Problems reported by Tom Lane.)
Also, when the destination already contains symbolic links, zic
should now work better on systems where the 'link' system call
does not follow symbolic links.
Changes to documentation and commentary
tz-link.htm now documents the relationship between release version
numbers and development-repository commit tags. (Suggested by
Paul Koning.)
The 'Theory' file now documents UT.
iso3166.tab now accents "Curaçao", and commentary now mentions
the names "Cabo Verde" and "Czechia". (Thanks to Jiří Boháč.)
Release 2016i - 2016-11-01 23:19:52 -0700
Briefly: Cyprus split into two time zones on 2016-10-30, and Tonga
reintroduces DST on 2016-11-06.
Changes to future timestamps
Pacific/Tongatapu begins DST on 2016-11-06 at 02:00, ending on
2017-01-15 at 03:00. Assume future observances in Tonga will be
from the first Sunday in November through the third Sunday in
January, like Fiji. (Thanks to Pulu ʻAnau.) Switch to numeric
time zone abbreviations for this zone.
Changes to past and future timestamps
Northern Cyprus is now +03 year round, causing a split in Cyprus
time zones starting 2016-10-30 at 04:00. This creates a zone
Asia/Famagusta. (Thanks to Even Scharning and Matt Johnson.)
Antarctica/Casey switched from +08 to +11 on 2016-10-22.
(Thanks to Steffen Thorsen.)
Changes to past timestamps
Several corrections were made for pre-1975 timestamps in Italy.
These affect Europe/Malta, Europe/Rome, Europe/San_Marino, and
Europe/Vatican.
First, the 1893-11-01 00:00 transition in Italy used the new UT
offset (+01), not the old (+00:49:56). (Thanks to Michael
Deckers.)
Second, rules for daylight saving in Italy were changed to agree
with Italy's National Institute of Metrological Research (INRiM)
except for 1944, as follows (thanks to Pierpaolo Bernardi, Brian
Inglis, and Michael Deckers):
The 1916-06-03 transition was at 24:00, not 00:00.
The 1916-10-01, 1919-10-05, and 1920-09-19 transitions were at
00:00, not 01:00.
The 1917-09-30 and 1918-10-06 transitions were at 24:00, not
01:00.
The 1944-09-17 transition was at 03:00, not 01:00. This
particular change is taken from Italian law as INRiM's table,
(which says 02:00) appears to have a typo here. Also, keep the
1944-04-03 transition for Europe/Rome, as Rome was controlled by
Germany then.
The 1967-1970 and 1972-1974 fallback transitions were at 01:00,
not 00:00.
Changes to code
The code should now be buildable on AmigaOS merely by setting the
appropriate Makefile variables. (From a patch by Carsten Larsen.)
Release 2016h - 2016-10-19 23:17:57 -0700
Changes to future timestamps
Asia/Gaza and Asia/Hebron end DST on 2016-10-29 at 01:00, not
2016-10-21 at 00:00. (Thanks to Sharef Mustafa.) Predict that
future fall transitions will be on the last Saturday of October
at 01:00, which is consistent with predicted spring transitions
on the last Saturday of March. (Thanks to Tim Parenti.)
Changes to past timestamps
In Turkey, transitions in 1986-1990 were at 01:00 standard time
not at 02:00, and the spring 1994 transition was on March 20, not
March 27. (Thanks to Kıvanç Yazan.)
Changes to past and future time zone abbreviations
Asia/Colombo now uses numeric time zone abbreviations like "+0530"
instead of alphabetic ones like "IST" and "LKT". Various
English-language sources use "IST", "LKT" and "SLST", with no
working consensus. (Usage of "SLST" mentioned by Sadika
Sumanapala.)
Changes to code
zic no longer mishandles relativizing file names when creating
symbolic links like /etc/localtime, when these symbolic links
are outside the usual directory hierarchy. This fixes a bug
introduced in 2016g. (Problem reported by Andreas Stieger.)
Changes to build procedure
New rules 'traditional_tarballs' and 'traditional_signatures' for
building just the traditional-format distribution. (Requested by
Deborah Goldsmith.)
The file 'version' is now put into the tzdata tarball too.
(Requested by Howard Hinnant.)
Changes to documentation and commentary
The 'Theory' file now has a section on interface stability.
(Requested by Paul Koning.) It also mentions features like
tm_zone and localtime_rz that have long been supported by the
reference code.
tz-link.htm has improved coverage of time zone boundaries suitable
for geolocation. (Thanks to heads-ups from Evan Siroky and Matt
Johnson.)
The US commentary now mentions Allen and the "day of two noons".
The Fiji commentary mentions the government's 2016-10-03 press
release. (Thanks to Raymond Kumar.)
Release 2016g - 2016-09-13 08:56:38 -0700
Changes to future timestamps
Turkey switched from EET/EEST (+02/+03) to permanent +03,
effective 2016-09-07. (Thanks to Burak AYDIN.) Use "+03" rather
than an invented abbreviation for the new time.
New leap second 2016-12-31 23:59:60 UTC as per IERS Bulletin C 52.
(Thanks to Tim Parenti.)
Changes to past timestamps
For America/Los_Angeles, spring-forward transition times have been
corrected from 02:00 to 02:01 in 1948, and from 02:00 to 01:00 in
1950-1966.
For zones using Soviet time on 1919-07-01, transitions to UT-based
time were at 00:00 UT, not at 02:00 local time. The affected
zones are Europe/Kirov, Europe/Moscow, Europe/Samara, and
Europe/Ulyanovsk. (Thanks to Alexander Belopolsky.)
Changes to past and future time zone abbreviations
The Factory zone now uses the time zone abbreviation -00 instead
of a long English-language string, as -00 is now the normal way to
represent an undefined time zone.
Several zones in Antarctica and the former Soviet Union, along
with zones intended for ships at sea that cannot use POSIX TZ
strings, now use numeric time zone abbreviations instead of
invented or obsolete alphanumeric abbreviations. The affected
zones are Antarctica/Casey, Antarctica/Davis,
Antarctica/DumontDUrville, Antarctica/Mawson, Antarctica/Rothera,
Antarctica/Syowa, Antarctica/Troll, Antarctica/Vostok,
Asia/Anadyr, Asia/Ashgabat, Asia/Baku, Asia/Bishkek, Asia/Chita,
Asia/Dushanbe, Asia/Irkutsk, Asia/Kamchatka, Asia/Khandyga,
Asia/Krasnoyarsk, Asia/Magadan, Asia/Omsk, Asia/Sakhalin,
Asia/Samarkand, Asia/Srednekolymsk, Asia/Tashkent, Asia/Tbilisi,
Asia/Ust-Nera, Asia/Vladivostok, Asia/Yakutsk, Asia/Yekaterinburg,
Asia/Yerevan, Etc/GMT-14, Etc/GMT-13, Etc/GMT-12, Etc/GMT-11,
Etc/GMT-10, Etc/GMT-9, Etc/GMT-8, Etc/GMT-7, Etc/GMT-6, Etc/GMT-5,
Etc/GMT-4, Etc/GMT-3, Etc/GMT-2, Etc/GMT-1, Etc/GMT+1, Etc/GMT+2,
Etc/GMT+3, Etc/GMT+4, Etc/GMT+5, Etc/GMT+6, Etc/GMT+7, Etc/GMT+8,
Etc/GMT+9, Etc/GMT+10, Etc/GMT+11, Etc/GMT+12, Europe/Kaliningrad,
Europe/Minsk, Europe/Samara, Europe/Volgograd, and
Indian/Kerguelen. For Europe/Moscow the invented abbreviation MSM
was replaced by +05, whereas MSK and MSD were kept as they are not
our invention and are widely used.
Changes to zone names
Rename Asia/Rangoon to Asia/Yangon, with a backward compatibility link.
(Thanks to David Massoud.)
Changes to code
zic no longer generates binary files containing POSIX TZ-like
strings that disagree with the local time type after the last
explicit transition in the data. This fixes a bug with
Africa/Casablanca and Africa/El_Aaiun in some year-2037 timestamps
on the reference platform. (Thanks to Alexander Belopolsky for
reporting the bug and suggesting a way forward.)
If the installed localtime and/or posixrules files are symbolic
links, zic now keeps them symbolic links when updating them, for
compatibility with platforms like OpenSUSE where other programs
configure these files as symlinks.
zic now avoids hard linking to symbolic links, avoids some
unnecessary mkdir and stat system calls, and uses shorter file
names internally.
zdump has a new -i option to generate transitions in a
more-compact but still human-readable format. This option is
experimental, and the output format may change in future versions.
(Thanks to Jon Skeet for suggesting that an option was needed,
and thanks to Tim Parenti and Chris Rovick for further comments.)
Changes to build procedure
An experimental distribution format is available, in addition
to the traditional format which will continue to be distributed.
The new format is a tarball tzdb-VERSION.tar.lz with signature
file tzdb-VERSION.tar.lz.asc. It unpacks to a top-level directory
tzdb-VERSION containing the code and data of the traditional
two-tarball format, along with extra data that may be useful.
(Thanks to Antonio Diaz Diaz, Oscar van Vlijmen, and many others
for comments about the experimental format.)
The release version number is now more accurate in the usual case
where releases are built from a Git repository. For example, if
23 commits and some working-file changes have been made since
release 2016g, the version number is now something like
'2016g-23-g50556e3-dirty' instead of the misleading '2016g'.
Tagged releases use the same version number format as before,
e.g., '2016g'. To support the more-accurate version number, its
specification has moved from a line in the Makefile to a new
source file 'version'.
The experimental distribution contains a file to2050.tzs that
contains what should be the output of 'zdump -i -c 2050' on
primary zones. If this file is available, 'make check' now checks
that zdump generates this output.
'make check_web' now works on Fedora-like distributions.
Changes to documentation and commentary
tzfile.5 now documents the new restriction on POSIX TZ-like
strings that is now implemented by zic.
Comments now cite URLs for some 1917-1921 Russian DST decrees.
(Thanks to Alexander Belopolsky.)
tz-link.htm mentions JuliaTime (thanks to Curtis Vogt) and Time4J
(thanks to Meno Hochschild) and ThreeTen-Extra, and its
description of Java 8 has been brought up to date (thanks to
Stephen Colebourne). Its description of local time on Mars has
been updated to match current practice, and URLs have been updated
and some obsolete ones removed.
Release 2016f - 2016-07-05 16:26:51 +0200
Changes affecting future timestamps
The Egyptian government changed its mind on short notice, and
Africa/Cairo will not introduce DST starting 2016-07-07 after all.
(Thanks to Mina Samuel.)
Asia/Novosibirsk switches from +06 to +07 on 2016-07-24 at 02:00.
(Thanks to Stepan Golosunov.)
Changes to past and future timestamps
Asia/Novokuznetsk and Asia/Novosibirsk now use numeric time zone
abbreviations instead of invented ones.
Changes affecting past timestamps
Europe/Minsk's 1992-03-29 spring-forward transition was at 02:00 not 00:00.
(Thanks to Stepan Golosunov.)
Release 2016e - 2016-06-14 08:46:16 -0700
Changes affecting future timestamps
Africa/Cairo observes DST in 2016 from July 7 to the end of October.
Guess October 27 and 24:00 transitions. (Thanks to Steffen Thorsen.)
For future years, guess April's last Thursday to October's last
Thursday except for Ramadan.
Changes affecting past timestamps
Locations while uninhabited now use '-00', not 'zzz', as a
placeholder time zone abbreviation. This is inspired by Internet
RFC 3339 and is more consistent with numeric time zone
abbreviations already used elsewhere. The change affects several
arctic and antarctic locations, e.g., America/Cambridge_Bay before
1920 and Antarctica/Troll before 2005.
Asia/Baku's 1992-09-27 transition from +04 (DST) to +04 (non-DST) was
at 03:00, not 23:00 the previous day. (Thanks to Michael Deckers.)
Changes to code
zic now outputs a dummy transition at time 2**31 - 1 in zones
whose POSIX-style TZ strings contain a '<'. This mostly works
around Qt bug 53071 <https://bugreports.qt.io/browse/QTBUG-53071>.
(Thanks to Zhanibek Adilbekov for reporting the Qt bug.)
Changes affecting documentation and commentary
tz-link.htm says why governments should give plenty of notice for
time zone or DST changes, and refers to Matt Johnson's blog post.
tz-link.htm mentions Tzdata for Elixir. (Thanks to Matt Johnson.)
Release 2016d - 2016-04-17 22:50:29 -0700
Changes affecting future timestamps
America/Caracas switches from -0430 to -04 on 2016-05-01 at 02:30.
(Thanks to Alexander Krivenyshev for the heads-up.)
Asia/Magadan switches from +10 to +11 on 2016-04-24 at 02:00.
(Thanks to Alexander Krivenyshev and Matt Johnson.)
New zone Asia/Tomsk, split off from Asia/Novosibirsk. It covers
Tomsk Oblast, Russia, which switches from +06 to +07 on 2016-05-29
at 02:00. (Thanks to Stepan Golosunov.)
Changes affecting past timestamps
New zone Europe/Kirov, split off from Europe/Volgograd. It covers
Kirov Oblast, Russia, which switched from +04/+05 to +03/+04 on
1989-03-26 at 02:00, roughly a year after Europe/Volgograd made
the same change. (Thanks to Stepan Golosunov.)
Russia and nearby locations had daylight-saving transitions on
1992-03-29 at 02:00 and 1992-09-27 at 03:00, instead of on
1992-03-28 at 23:00 and 1992-09-26 at 23:00. (Thanks to Stepan
Golosunov.)
Many corrections to historical time in Kazakhstan from 1991
through 2005. (Thanks to Stepan Golosunov.) Replace Kazakhstan's
invented time zone abbreviations with numeric abbreviations.
Changes to commentary
Mention Internet RFCs 7808 (TZDIST) and 7809 (CalDAV time zone references).
Release 2016c - 2016-03-23 00:51:27 -0700
Changes affecting future timestamps
Azerbaijan no longer observes DST. (Thanks to Steffen Thorsen.)
Chile reverts from permanent to seasonal DST. (Thanks to Juan
Correa for the heads-up, and to Tim Parenti for corrections.)
Guess that future transitions are August's and May's second
Saturdays at 24:00 mainland time. Also, call the period from
2014-09-07 through 2016-05-14 daylight saving time instead of
standard time, as that seems more appropriate now.
Changes affecting past timestamps
Europe/Kaliningrad and Europe/Vilnius changed from +03/+04 to
+02/+03 on 1989-03-26, not 1991-03-31. Europe/Volgograd changed
from +04/+05 to +03/+04 on 1988-03-27, not 1989-03-26.
(Thanks to Stepan Golosunov.)
Changes to commentary
Several updates and URLs for historical and proposed Russian changes.
(Thanks to Stepan Golosunov, Matt Johnson, and Alexander Krivenyshev.)
Release 2016b - 2016-03-12 17:30:14 -0800
Compatibility note
Starting with release 2016b, some data entries cause zic implementations
derived from tz releases 2005j through 2015e to issue warnings like
"time zone abbreviation differs from POSIX standard (+03)".
These warnings should not otherwise affect zic's output and can safely be
ignored on today's platforms, as the warnings refer to a restriction in
POSIX.1-1988 that was removed in POSIX.1-2001. One way to suppress the
warnings is to upgrade to zic derived from tz releases 2015f and later.
Changes affecting future timestamps
New zones Europe/Astrakhan and Europe/Ulyanovsk for Astrakhan and
Ulyanovsk Oblasts, Russia, both of which will switch from +03 to +04 on
2016-03-27 at 02:00 local time. They need distinct zones since their
post-1970 histories disagree. New zone Asia/Barnaul for Altai Krai and
Altai Republic, Russia, which will switch from +06 to +07 on the same date
and local time. The Astrakhan change is already official; the others have
passed the first reading in the State Duma and are extremely likely.
Also, Asia/Sakhalin moves from +10 to +11 on 2016-03-27 at 02:00.
(Thanks to Alexander Krivenyshev for the heads-up, and to Matt Johnson
and Stepan Golosunov for followup.)
As a trial of a new system that needs less information to be made up,
the new zones use numeric time zone abbreviations like "+04"
instead of invented abbreviations like "ASTT".
Haiti will not observe DST in 2016. (Thanks to Jean Antoine via
Steffen Thorsen.)
Palestine's spring-forward transition on 2016-03-26 is at 01:00, not 00:00.
(Thanks to Hannah Kreitem.) Guess future transitions will be March's last
Saturday at 01:00, not March's last Friday at 24:00.
Changes affecting past timestamps
Europe/Chisinau observed DST during 1990, and switched from +04 to
+03 at 1990-05-06 02:00, instead of switching from +03 to +02.
(Thanks to Stepan Golosunov.)
1991 abbreviations in Europe/Samara should be SAMT/SAMST, not
KUYT/KUYST. (Thanks to Stepan Golosunov.)
Changes to code
tzselect's diagnostics and checking, and checktab.awk's checking,
have been improved. (Thanks to J William Piggott.)
tzcode now builds under MinGW. (Thanks to Ian Abbott and Esben Haabendal.)
tzselect now tests Julian-date TZ settings more accurately.
(Thanks to J William Piggott.)
Changes to commentary
Comments in zone tables have been improved. (Thanks to J William Piggott.)
tzselect again limits its menu comments so that menus fit on a
24×80 alphanumeric display.
A new web page tz-how-to.html. (Thanks to Bill Seymour.)
In the Theory file, the description of possible time zone abbreviations in
tzdata has been cleaned up, as the old description was unclear and
inconsistent. (Thanks to Alain Mouette for reporting the problem.)
Release 2016a - 2016-01-26 23:28:02 -0800
Changes affecting future timestamps
America/Cayman will not observe daylight saving this year after all.
Revert our guess that it would. (Thanks to Matt Johnson.)
Asia/Chita switches from +0800 to +0900 on 2016-03-27 at 02:00.
(Thanks to Alexander Krivenyshev.)
Asia/Tehran now has DST predictions for the year 2038 and later,
to be March 21 00:00 to September 21 00:00. This is likely better
than predicting no DST, albeit off by a day every now and then.
Changes affecting past and future timestamps
America/Metlakatla switched from PST all year to AKST/AKDT on
2015-11-01 at 02:00. (Thanks to Steffen Thorsen.)
America/Santa_Isabel has been removed, and replaced with a
backward compatibility link to America/Tijuana. Its contents were
apparently based on a misreading of Mexican legislation.
Changes affecting past timestamps
Asia/Karachi's two transition times in 2002 were off by a minute.
(Thanks to Matt Johnson.)
Changes affecting build procedure
An installer can now combine leap seconds with use of the backzone file,
e.g., with 'make PACKRATDATA=backzone REDO=posix_right zones'.
The old 'make posix_packrat' rule is now marked as obsolescent.
(Thanks to Ian Abbott for an initial implementation.)
Changes affecting documentation and commentary
A new file LICENSE makes it easier to see that the code and data
are mostly public-domain. (Thanks to James Knight.) The three
non-public-domain files now use the current (3-clause) BSD license
instead of older versions of that license.
tz-link.htm mentions the BDE library (thanks to Andrew Paprocki),
CCTZ (thanks to Tim Parenti), TimeJones.com, and has a new section
on editing tz source files (with a mention of Sublime zoneinfo,
thanks to Gilmore Davidson).
The Theory and asia files now mention the 2015 book "The Global
Transformation of Time, 1870-1950", and cite a couple of reviews.
The America/Chicago entry now documents the informal use of US
central time in Fort Pierre, South Dakota. (Thanks to Rick
McDermid, Matt Johnson, and Steve Jones.)
Release 2015g - 2015-10-01 00:39:51 -0700
Changes affecting future timestamps
Turkey's 2015 fall-back transition is scheduled for Nov. 8, not Oct. 25.
(Thanks to Fatih.)
Norfolk moves from +1130 to +1100 on 2015-10-04 at 02:00 local time.
(Thanks to Alexander Krivenyshev.)
Fiji's 2016 fall-back transition is scheduled for January 17, not 24.
(Thanks to Ken Rylander.)
Fort Nelson, British Columbia will not fall back on 2015-11-01. It has
effectively been on MST (-0700) since it advanced its clocks on 2015-03-08.
New zone America/Fort_Nelson. (Thanks to Matt Johnson.)
Changes affecting past timestamps
Norfolk observed DST from 1974-10-27 02:00 to 1975-03-02 02:00.
Changes affecting code
localtime no longer mishandles America/Anchorage after 2037.
(Thanks to Bradley White for reporting the bug.)
On hosts with signed 32-bit time_t, localtime no longer mishandles
Pacific/Fiji after 2038-01-16 14:00 UTC.
The localtime module allows the variables 'timezone', 'daylight',
and 'altzone' to be in common storage shared with other modules,
and declares them in case the system <time.h> does not.
(Problems reported by Kees Dekker.)
On platforms with tm_zone, strftime.c now assumes it is not NULL.
This simplifies the code and is consistent with zdump.c.
(Problem reported by Christos Zoulas.)
Changes affecting documentation
The tzfile man page now documents that transition times denote the
starts (not the ends) of the corresponding time periods.
(Ambiguity reported by Bill Seymour.)
Release 2015f - 2015-08-10 18:06:56 -0700
Changes affecting future timestamps
North Korea switches to +0830 on 2015-08-15. (Thanks to Steffen Thorsen.)
The abbreviation remains "KST". (Thanks to Robert Elz.)
Uruguay no longer observes DST. (Thanks to Steffen Thorsen
and Pablo Camargo.)
Changes affecting past and future timestamps
Moldova starts and ends DST at 00:00 UTC, not at 01:00 UTC.
(Thanks to Roman Tudos.)
Changes affecting data format and code
zic's '-y YEARISTYPE' option is no longer documented. The TYPE
field of a Rule line should now be '-'; the old values 'even',
'odd', 'uspres', 'nonpres', 'nonuspres' were already undocumented.
Although the implementation has not changed, these features do not
work in the default installation, they are not used in the data,
and they are now considered obsolescent.
zic now checks that two rules don't take effect at the same time.
(Thanks to Jon Skeet and Arthur David Olson.) Constraints on
simultaneity are now documented.
The two characters '%z' in a zone format now stand for the UT
offset, e.g., '-07' for seven hours behind UT and '+0530' for
five hours and thirty minutes ahead. This better supports time
zone abbreviations conforming to POSIX.1-2001 and later.
Changes affecting installed data files
Comments for America/Halifax and America/Glace_Bay have been improved.
(Thanks to Brian Inglis.)
Data entries have been simplified for Atlantic/Canary, Europe/Simferopol,
Europe/Sofia, and Europe/Tallinn. This yields slightly smaller
installed data files for Europe/Simferopol and Europe/Tallinn.
It does not affect timestamps. (Thanks to Howard Hinnant.)
Changes affecting code
zdump and zic no longer warn about valid time zone abbreviations
like '-05'.
Some Visual Studio 2013 warnings have been suppressed.
(Thanks to Kees Dekker.)
'date' no longer sets the time of day and its -a, -d, -n and -t
options have been removed. Long obsolescent, the implementation
of these features had porting problems. Builders no longer need
to configure HAVE_ADJTIME, HAVE_SETTIMEOFDAY, or HAVE_UTMPX_H.
(Thanks to Kees Dekker for pointing out the problem.)
Changes affecting documentation
The Theory file mentions naming issues earlier, as these seem to be
poorly publicized (thanks to Gilmore Davidson for reporting the problem).
tz-link.htm mentions Time Zone Database Parser (thanks to Howard Hinnant).
Mention that Herbert Samuel introduced the term "Summer Time".
Release 2015e - 2015-06-13 10:56:02 -0700
Changes affecting future timestamps
Morocco will suspend DST from 2015-06-14 03:00 through 2015-07-19 02:00,
not 06-13 and 07-18 as we had guessed. (Thanks to Milamber.)
Assume Cayman Islands will observe DST starting next year, using US rules.
Although it isn't guaranteed, it is the most likely.
Changes affecting data format
The file 'iso3166.tab' now uses UTF-8, so that its entries can better
spell the names of Åland Islands, Côte d'Ivoire, and Réunion.
Changes affecting code
When displaying data, tzselect converts it to the current locale's
encoding if the iconv command works. (Problem reported by random832.)
tzselect no longer mishandles Dominica, fixing a bug introduced
in Release 2014f. (Problem reported by Owen Leibman.)
zic -l no longer fails when compiled with -DTZDEFAULT=\"/etc/localtime\".
This fixes a bug introduced in Release 2014f.
(Problem reported by Leonardo Chiquitto.)
Release 2015d - 2015-04-24 08:09:46 -0700
Changes affecting future timestamps
Egypt will not observe DST in 2015 and will consider canceling it
permanently. For now, assume no DST indefinitely.
(Thanks to Ahmed Nazmy and Tim Parenti.)
Changes affecting past timestamps
America/Whitehorse switched from UT -09 to -08 on 1967-05-28, not
1966-07-01. Also, Yukon's time zone history is documented better.
(Thanks to Brian Inglis and Dennis Ferguson.)
Change affecting past and future time zone abbreviations
The abbreviations for Hawaii-Aleutian standard and daylight times
have been changed from HAST/HADT to HST/HDT, as per US Government
Printing Office style. This affects only America/Adak since 1983,
as America/Honolulu was already using the new style.
Changes affecting code
zic has some minor performance improvements.
Release 2015c - 2015-04-11 08:55:55 -0700
Changes affecting future timestamps
Egypt's spring-forward transition is at 24:00 on April's last Thursday,
not 00:00 on April's last Friday. 2015's transition will therefore be on
Thursday, April 30 at 24:00, not Friday, April 24 at 00:00. Similar fixes
apply to 2026, 2037, 2043, etc. (Thanks to Steffen Thorsen.)
Changes affecting past timestamps
The following changes affect some pre-1991 Chile-related timestamps
in America/Santiago, Antarctica/Palmer, and Pacific/Easter.
The 1910 transition was January 10, not January 1.
The 1918 transition was September 10, not September 1.
The UT -04 time observed from 1932 to 1942 is now considered to
be standard time, not year-round DST.
Santiago observed DST (UT -03) from 1946-07-15 through
1946-08-31, then reverted to standard time, then switched to -05
on 1947-04-01.
Assume transitions before 1968 were at 00:00, since we have no data
saying otherwise.
The spring 1988 transition was 1988-10-09, not 1988-10-02.
The fall 1990 transition was 1990-03-11, not 1990-03-18.
Assume no UT offset change for Pacific/Easter on 1890-01-01,
and omit all transitions on Pacific/Easter from 1942 through 1946
since we have no data suggesting that they existed.
One more zone has been turned into a link, as it differed
from an existing zone only for older timestamps. As usual,
this change affects UT offsets in pre-1970 timestamps only.
The zone's old contents have been moved to the 'backzone' file.
The affected zone is America/Montreal.
Changes affecting commentary
Mention the TZUpdater tool.
Mention "The Time Now". (Thanks to Brandon Ramsey.)
Release 2015b - 2015-03-19 23:28:11 -0700
Changes affecting future timestamps
Mongolia will start observing DST again this year, from the last
Saturday in March at 02:00 to the last Saturday in September at 00:00.
(Thanks to Ganbold Tsagaankhuu.)
Palestine will start DST on March 28, not March 27. Also,
correct the fall 2014 transition from September 26 to October 24.
Adjust future predictions accordingly. (Thanks to Steffen Thorsen.)
Changes affecting past timestamps
The 1982 zone shift in Pacific/Easter has been corrected, fixing a 2015a
regression. (Thanks to Stuart Bishop for reporting the problem.)
Some more zones have been turned into links, when they differed
from existing zones only for older timestamps. As usual,
these changes affect UT offsets in pre-1970 timestamps only.
Their old contents have been moved to the 'backzone' file.
The affected zones are: America/Antigua, America/Cayman,
Pacific/Midway, and Pacific/Saipan.
Changes affecting time zone abbreviations
Correct the 1992-2010 DST abbreviation in Volgograd from "MSK" to "MSD".
(Thanks to Hank W.)
Changes affecting code
Fix integer overflow bug in reference 'mktime' implementation.
(Problem reported by Jörg Richter.)
Allow -Dtime_tz=time_t compilations, and allow -Dtime_tz=... libraries
to be used in the same executable as standard-library time_t functions.
(Problems reported by Bradley White.)
Changes affecting commentary
Cite the recent Mexican decree changing Quintana Roo's time zone.
(Thanks to Carlos Raúl Perasso.)
Likewise for the recent Chilean decree. (Thanks to Eduardo Romero Urra.)
Update info about Mars time.
Release 2015a - 2015-01-29 22:35:20 -0800
Changes affecting future timestamps
The Mexican state of Quintana Roo, represented by America/Cancun,
will shift from Central Time with DST to Eastern Time without DST
on 2015-02-01 at 02:00. (Thanks to Steffen Thorsen and Gwillim Law.)
Chile will not change clocks in April or thereafter; its new standard time
will be its old daylight saving time. This affects America/Santiago,
Pacific/Easter, and Antarctica/Palmer. (Thanks to Juan Correa.)
New leap second 2015-06-30 23:59:60 UTC as per IERS Bulletin C 49.
(Thanks to Tim Parenti.)
Changes affecting past timestamps
Iceland observed DST in 1919 and 1921, and its 1939 fallback
transition was Oct. 29, not Nov. 29. Remove incorrect data from
Shanks about time in Iceland between 1837 and 1908.
Some more zones have been turned into links, when they differed
from existing zones only for older timestamps. As usual,
these changes affect UT offsets in pre-1970 timestamps only.
Their old contents have been moved to the 'backzone' file.
The affected zones are: Asia/Aden, Asia/Bahrain, Asia/Kuwait,
and Asia/Muscat.
Changes affecting code
tzalloc now scrubs time zone abbreviations compatibly with the way
that tzset always has, by replacing invalid bytes with '_' and by
shortening too-long abbreviations.
tzselect ports to POSIX awk implementations, no longer mishandles
POSIX TZ settings when GNU awk is used, and reports POSIX TZ
settings to the user. (Thanks to Stefan Kuhn.)
Changes affecting build procedure
'make check' now checks for links to links in the data.
One such link (for Africa/Asmera) has been fixed.
(Thanks to Stephen Colebourne for pointing out the problem.)
Changes affecting commentary
The leapseconds file commentary now mentions the expiration date.
(Problem reported by Martin Burnicki.)
Update Mexican Library of Congress URL.
Release 2014j - 2014-11-10 17:37:11 -0800
Changes affecting current and future timestamps
Turks & Caicos' switch from US eastern time to UT -04 year-round
did not occur on 2014-11-02 at 02:00. It's currently scheduled
for 2015-11-01 at 02:00. (Thanks to Chris Walton.)
Changes affecting past timestamps
Many pre-1989 timestamps have been corrected for Asia/Seoul and
Asia/Pyongyang, based on sources for the Korean-language Wikipedia
entry for time in Korea. (Thanks to Sanghyuk Jung.) Also, no
longer guess that Pyongyang mimicked Seoul time after World War II,
as this is politically implausible.
Some more zones have been turned into links, when they differed
from existing zones only for older timestamps. As usual,
these changes affect UT offsets in pre-1970 timestamps only.
Their old contents have been moved to the 'backzone' file.
The affected zones are: Africa/Addis_Ababa, Africa/Asmara,
Africa/Dar_es_Salaam, Africa/Djibouti, Africa/Kampala,
Africa/Mogadishu, Indian/Antananarivo, Indian/Comoro, and
Indian/Mayotte.
Changes affecting commentary
The commentary is less enthusiastic about Shanks as a source,
and is more careful to distinguish UT from UTC.
Release 2014i - 2014-10-21 22:04:57 -0700
Changes affecting future timestamps
Pacific/Fiji will observe DST from 2014-11-02 02:00 to 2015-01-18 03:00.
(Thanks to Ken Rylander for the heads-up.) Guess that future
years will use a similar pattern.
A new Zone Pacific/Bougainville, for the part of Papua New Guinea
that plans to switch from UT +10 to +11 on 2014-12-28 at 02:00.
(Thanks to Kiley Walbom for the heads-up.)
Changes affecting time zone abbreviations
Since Belarus is not changing its clocks even though Moscow is,
the time zone abbreviation in Europe/Minsk is changing from FET
to its more-traditional value MSK on 2014-10-26 at 01:00.
(Thanks to Alexander Bokovoy for the heads-up about Belarus.)
The new abbreviation IDT stands for the pre-1976 use of UT +08 in
Indochina, to distinguish it better from ICT (+07).
Changes affecting past timestamps
Many timestamps have been corrected for Asia/Ho_Chi_Minh before 1976
(thanks to Trần Ngọc Quân for an indirect pointer to Trần Tiến Bình's
authoritative book). Asia/Ho_Chi_Minh has been added to
zone1970.tab, to give tzselect users in Vietnam two choices,
since north and south Vietnam disagreed after our 1970 cutoff.
Asia/Phnom_Penh and Asia/Vientiane have been turned into links, as
they differed from existing zones only for older timestamps. As
usual, these changes affect pre-1970 timestamps only. Their old
contents have been moved to the 'backzone' file.
Changes affecting code
The time-related library functions now set errno on failure, and
some crashes in the new tzalloc-related library functions have
been fixed. (Thanks to Christos Zoulas for reporting most of
these problems and for suggesting fixes.)
If USG_COMPAT is defined and the requested timestamp is standard time,
the tz library's localtime and mktime functions now set the extern
variable timezone to a value appropriate for that timestamp; and
similarly for ALTZONE, daylight saving time, and the altzone variable.
This change is a companion to the tzname change in 2014h, and is
designed to make timezone and altzone more compatible with tzname.
The tz library's functions now set errno to EOVERFLOW if they fail
because the result cannot be represented. ctime and ctime_r now
return NULL and set errno when a timestamp is out of range, rather
than having undefined behavior.
Some bugs associated with the new 2014g functions have been fixed.
This includes a bug that largely incapacitated the new functions
time2posix_z and posix2time_z. (Thanks to Christos Zoulas.)
It also includes some uses of uninitialized variables after tzalloc.
The new code uses the standard type 'ssize_t', which the Makefile
now gives porting advice about.
Changes affecting commentary
Updated URLs for NRC Canada (thanks to Matt Johnson and Brian Inglis).
Release 2014h - 2014-09-25 18:59:03 -0700
Changes affecting past timestamps
America/Jamaica's 1974 spring-forward transition was Jan. 6, not Apr. 28.
Shanks says Asia/Novokuznetsk switched from LMT (not "NMT") on 1924-05-01,
not 1920-01-06. The old entry was based on a misinterpretation of Shanks.
Some more zones have been turned into links, when they differed
from existing zones only for older timestamps. As usual,
these changes affect UT offsets in pre-1970 timestamps only.
Their old contents have been moved to the 'backzone' file.
The affected zones are: Africa/Blantyre, Africa/Bujumbura,
Africa/Gaborone, Africa/Harare, Africa/Kigali, Africa/Lubumbashi,
Africa/Lusaka, Africa/Maseru, and Africa/Mbabane.
Changes affecting code
zdump -V and -v now output gmtoff= values on all platforms,
not merely on platforms defining TM_GMTOFF.
The tz library's localtime and mktime functions now set tzname to a value
appropriate for the requested timestamp, and zdump now uses this
on platforms not defining TM_ZONE, fixing a 2014g regression.
(Thanks to Tim Parenti for reporting the problem.)
The tz library no longer sets tzname if localtime or mktime fails.
zdump -c no longer mishandles transitions near year boundaries.
(Thanks to Tim Parenti for reporting the problem.)
An access to uninitialized data has been fixed.
(Thanks to Jörg Richter for reporting the problem.)
When THREAD_SAFE is defined, the code ports to the C11 memory model.
A memory leak has been fixed if ALL_STATE and THREAD_SAFE are defined
and two threads race to initialize data used by gmtime-like functions.
(Thanks to Andy Heninger for reporting the problems.)
Changes affecting build procedure
'make check' now checks better for properly-sorted data.
Changes affecting documentation and commentary
zdump's gmtoff=N output is now documented, and its isdst=D output
is now documented to possibly output D values other than 0 or 1.
zdump -c's treatment of years is now documented to use the
Gregorian calendar and Universal Time without leap seconds,
and its behavior at cutoff boundaries is now documented better.
(Thanks to Arthur David Olson and Tim Parenti for reporting the problems.)
Programs are now documented to use the proleptic Gregorian calendar.
(Thanks to Alan Barrett for the suggestion.)
Fractional-second GMT offsets have been documented for civil time
in 19th-century Chennai, Jakarta, and New York.
Release 2014g - 2014-08-28 12:31:23 -0700
Changes affecting future timestamps
Turks & Caicos is switching from US eastern time to UT -04
year-round, modeled as a switch on 2014-11-02 at 02:00.
[As noted in 2014j, this switch was later delayed.]
Changes affecting past timestamps
Time in Russia or the USSR before 1926 or so has been corrected by
a few seconds in the following zones: Asia/Irkutsk,
Asia/Krasnoyarsk, Asia/Omsk, Asia/Samarkand, Asia/Tbilisi,
Asia/Vladivostok, Asia/Yakutsk, Europe/Riga, Europe/Samara. For
Asia/Yekaterinburg the correction is a few minutes. (Thanks to
Vladimir Karpinsky.)
The Portuguese decree of 1911-05-26 took effect on 1912-01-01.
This affects 1911 timestamps in Africa/Bissau, Africa/Luanda,
Atlantic/Azores, and Atlantic/Madeira. Also, Lisbon's pre-1912
GMT offset was -0:36:45 (rounded from -0:36:44.68), not -0:36:32.
(Thanks to Stephen Colebourne for pointing to the decree.)
Asia/Dhaka ended DST on 2009-12-31 at 24:00, not 23:59.
A new file 'backzone' contains data which may appeal to
connoisseurs of old timestamps, although it is out of scope for
the tz database, is often poorly sourced, and contains some data
that is known to be incorrect. The new file is not recommended
for ordinary use and its entries are not installed by default.
(Thanks to Lester Caine for the high-quality Jersey, Guernsey, and
Isle of Man entries.)
Some more zones have been turned into links, when they differed
from existing zones only for older timestamps. As usual,
these changes affect UT offsets in pre-1970 timestamps only.
Their old contents have been moved to the 'backzone' file.
The affected zones are: Africa/Bangui, Africa/Brazzaville,
Africa/Douala, Africa/Kinshasa, Africa/Libreville, Africa/Luanda,
Africa/Malabo, Africa/Niamey, and Africa/Porto-Novo.
Changes affecting code
Unless NETBSD_INSPIRED is defined to 0, the tz library now
supplies functions for creating and using objects that represent
timezones. The new functions are tzalloc, tzfree, localtime_rz,
mktime_z, and (if STD_INSPIRED is also defined) posix2time_z and
time2posix_z. They are intended for performance: for example,
localtime_rz (unlike localtime_r) is trivially thread-safe without
locking. (Thanks to Christos Zoulas for proposing NetBSD-inspired
functions, and to Alan Barrett and Jonathan Lennox for helping to
debug the change.)
zdump now builds with the tz library unless USE_LTZ is defined to 0,
This lets zdump use tz features even if the system library lacks them.
To build zdump with the system library, use 'make CFLAGS=-DUSE_LTZ=0
TZDOBJS=zdump.o CHECK_TIME_T_ALTERNATIVES='.
zdump now uses localtime_rz if available, as it's significantly faster,
and it can help zdump better diagnose invalid timezone names.
Define HAVE_LOCALTIME_RZ to 0 to suppress this. HAVE_LOCALTIME_RZ
defaults to 1 if NETBSD_INSPIRED && USE_LTZ. When localtime_rz is
not available, zdump now uses localtime_r and tzset if available,
as this is a bit cleaner and faster than plain localtime. Compile
with -DHAVE_LOCALTIME_R=0 and/or -DHAVE_TZSET=0 if your system
lacks these two functions.
If THREAD_SAFE is defined to 1, the tz library is now thread-safe.
Although not needed for tz's own applications, which are single-threaded,
this supports POSIX better if the tz library is used in multithreaded apps.
Some crashes have been fixed when zdump or the tz library is given
invalid or outlandish input.
The tz library no longer mishandles leap seconds on platforms with
unsigned time_t in timezones that lack ordinary transitions after 1970.
The tz code now attempts to infer TM_GMTOFF and TM_ZONE if not
already defined, to make it easier to configure on common platforms.
Define NO_TM_GMTOFF and NO_TM_ZONE to suppress this.
Unless the new macro UNINIT_TRAP is defined to 1, the tz code now
assumes that reading uninitialized memory yields garbage values
but does not cause other problems such as traps.
If TM_GMTOFF is defined and UNINIT_TRAP is 0, mktime is now
more likely to guess right for ambiguous timestamps near
transitions where tm_isdst does not change.
If HAVE_STRFTIME_L is defined to 1, the tz library now defines
strftime_l for compatibility with recent versions of POSIX.
Only the C locale is supported, though. HAVE_STRFTIME_L defaults
to 1 on recent POSIX versions, and to 0 otherwise.
tzselect -c now uses a hybrid distance measure that works better
in Africa. (Thanks to Alan Barrett for noting the problem.)
The C source code now ports to NetBSD when GCC_DEBUG_FLAGS is used,
or when time_tz is defined.
When HAVE_UTMPX_H is set the 'date' command now builds on systems
whose <utmpx.h> file does not define WTMPX_FILE, and when setting
the date it updates the wtmpx file if _PATH_WTMPX is defined.
This affects GNU/Linux and similar systems.
For easier maintenance later, some C code has been simplified,
some lint has been removed, and the code has been tweaked so that
plain 'make' is more likely to work.
The C type 'bool' is now used for boolean values, instead of 'int'.
The long-obsolete LOCALE_HOME code has been removed.
The long-obsolete 'gtime' function has been removed.
Changes affecting build procedure
'zdump' no longer links in ialloc.o, as it's not needed.
'make check_time_t_alternatives' no longer assumes GNU diff.
Changes affecting distribution tarballs
The files checktab.awk and zoneinfo2tdf.pl are now distributed in
the tzdata tarball instead of the tzcode tarball, since they help
maintain the data. The NEWS and Theory files are now also
distributed in the tzdata tarball, as they're relevant for data.
(Thanks to Alan Barrett for pointing this out.) Also, the
leapseconds.awk file is no longer distributed in the tzcode
tarball, since it belongs in the tzdata tarball (where 2014f
inadvertently also distributed it).
Changes affecting documentation and commentary
A new file CONTRIBUTING is distributed. (Thanks to Tim Parenti for
suggesting a CONTRIBUTING file, and to Tony Finch and Walter Harms
for debugging it.)
The man pages have been updated to use function prototypes,
to document thread-safe variants like localtime_r, and to document
the NetBSD-inspired functions tzalloc, tzfree, localtime_rz, and
mktime_z.
The fields in Link lines have been renamed to be more descriptive
and more like the parameters of 'ln'. LINK-FROM has become TARGET,
and LINK-TO has become LINK-NAME.
tz-link.htm mentions the IETF's tzdist working group; Windows
Runtime etc. (thanks to Matt Johnson); and HP-UX's tztab.
Some broken URLs have been fixed in the commentary. (Thanks to
Lester Caine.)
Commentary about Philippines DST has been updated, and commentary
on pre-1970 time in India has been added.
Release 2014f - 2014-08-05 17:42:36 -0700
Changes affecting future timestamps
Russia will subtract an hour from most of its time zones on 2014-10-26
at 02:00 local time. (Thanks to Alexander Krivenyshev.)
There are a few exceptions: Magadan Oblast (Asia/Magadan) and Zabaykalsky
Krai are subtracting two hours; conversely, Chukotka Autonomous Okrug
(Asia/Anadyr), Kamchatka Krai (Asia/Kamchatka), Kemerovo Oblast
(Asia/Novokuznetsk), and the Samara Oblast and the Udmurt Republic
(Europe/Samara) are not changing their clocks. The changed zones are
Europe/Kaliningrad, Europe/Moscow, Europe/Simferopol, Europe/Volgograd,
Asia/Yekaterinburg, Asia/Omsk, Asia/Novosibirsk, Asia/Krasnoyarsk,
Asia/Irkutsk, Asia/Yakutsk, Asia/Vladivostok, Asia/Khandyga,
Asia/Sakhalin, and Asia/Ust-Nera; Asia/Magadan will have two hours
subtracted; and Asia/Novokuznetsk's time zone abbreviation is affected,
but not its UTC offset. Two zones are added: Asia/Chita (split
from Asia/Yakutsk, and also with two hours subtracted) and
Asia/Srednekolymsk (split from Asia/Magadan, but with only one hour
subtracted). (Thanks to Tim Parenti for much of the above.)
Changes affecting time zone abbreviations
Australian eastern time zone abbreviations are now AEST/AEDT not EST,
and similarly for the other Australian zones. That is, for eastern
standard and daylight saving time the abbreviations are AEST and AEDT
instead of the former EST for both; similarly, ACST/ACDT, ACWST/ACWDT,
and AWST/AWDT are now used instead of the former CST, CWST, and WST.
This change does not affect UT offsets, only time zone abbreviations.
(Thanks to Rich Tibbett and many others.)
Asia/Novokuznetsk shifts from NOVT to KRAT (remaining on UT +07)
effective 2014-10-26 at 02:00 local time.
The time zone abbreviation for Xinjiang Time (observed in Ürümqi)
has been changed from URUT to XJT. (Thanks to Luther Ma.)
Prefer MSK/MSD for Moscow time in Russia, even in other cities.
Similarly, prefer EET/EEST for eastern European time in Russia.
Change time zone abbreviations in (western) Samoa to use "ST" and
"DT" suffixes, as this is more likely to match common practice.
Prefix "W" to (western) Samoa time when its standard-time offset
disagrees with that of American Samoa.
America/Metlakatla now uses PST, not MeST, to abbreviate its time zone.
Time zone abbreviations have been updated for Japan's two time
zones used 1896-1937. JWST now stands for Western Standard
Time, and JCST for Central Standard Time (formerly this was CJT).
These abbreviations are now used for time in Korea, Taiwan,
and Sakhalin while controlled by Japan.
Changes affecting past timestamps
China's five zones have been simplified to two, since the post-1970
differences in the other three seem to have been imaginary. The
zones Asia/Harbin, Asia/Chongqing, and Asia/Kashgar have been
removed; backwards-compatibility links still work, albeit with
different behaviors for timestamps before May 1980. Asia/Urumqi's
1980 transition to UT +08 has been removed, so that it is now at
+06 and not +08. (Thanks to Luther Ma and to Alois Treindl;
Treindl sent helpful translations of two papers by Guo Qingsheng.)
Some zones have been turned into links, when they differed from existing
zones only for older UT offsets where data entries were likely invented.
These changes affect UT offsets in pre-1970 timestamps only. This is
similar to the change in release 2013e, except this time for western
Africa. The affected zones are: Africa/Bamako, Africa/Banjul,
Africa/Conakry, Africa/Dakar, Africa/Freetown, Africa/Lome,
Africa/Nouakchott, Africa/Ouagadougou, Africa/Sao_Tome, and
Atlantic/St_Helena. This also affects the backwards-compatibility
link Africa/Timbuktu. (Thanks to Alan Barrett, Stephen Colebourne,
Tim Parenti, and David Patte for reporting problems in earlier
versions of this change.)
Asia/Shanghai's pre-standard-time UT offset has been changed from
8:05:57 to 8:05:43, the location of Xujiahui Observatory. Its
transition to standard time has been changed from 1928 to 1901.
Asia/Taipei switched to JWST on 1896-01-01, then to JST on 1937-10-01,
then to CST on 1945-09-21 at 01:00, and did not observe DST in 1945.
In 1946 it observed DST from 05-15 through 09-30; in 1947
from 04-15 through 10-31; and in 1979 from 07-01 through 09-30.
(Thanks to Yu-Cheng Chuang.)
Asia/Riyadh's transition to standard time is now 1947-03-14, not 1950.
Europe/Helsinki's 1942 fall-back transition was 10-04 at 01:00, not
10-03 at 00:00. (Thanks to Konstantin Hyppönen.)
Pacific/Pago_Pago has been changed from UT -11:30 to -11 for the
period from 1911 to 1950.
Pacific/Chatham has been changed to New Zealand standard time plus
45 minutes for the period before 1957, reflecting a 1956 remark in
the New Zealand parliament.
Europe/Budapest has several pre-1946 corrections: in 1918 the transition
out of DST was on 09-16, not 09-29; in 1919 it was on 11-24, not 09-15; in
1945 it was on 11-01, not 11-03; in 1941 the transition to DST was 04-08
not 04-06 at 02:00; and there was no DST in 1920.
Africa/Accra is now assumed to have observed DST from 1920 through 1935.
Time in Russia before 1927 or so has been corrected by a few seconds in
the following zones: Europe/Moscow, Asia/Irkutsk, Asia/Tbilisi,
Asia/Tashkent, Asia/Vladivostok, Asia/Yekaterinburg, Europe/Helsinki, and
Europe/Riga. Also, Moscow's location has been changed to its Kilometer 0
point. (Thanks to Vladimir Karpinsky for the Moscow changes.)
Changes affecting data format
A new file 'zone1970.tab' supersedes 'zone.tab' in the installed data.
The new file's extended format allows multiple country codes per zone.
The older file is still installed but is deprecated; its format is
not changing and it will still be distributed for a while, but new
applications should use the new file.
The new file format simplifies maintenance of obscure locations.
To test this, it adds coverage for the Crozet Islands and the
Scattered Islands. (Thanks to Tobias Conradi and Antoine Leca.)
The file 'iso3166.tab' is planned to switch from ASCII to UTF-8.
It is still ASCII now, but commentary about the switch has been added.
The new file 'zone1970.tab' already uses UTF-8.
Changes affecting code
'localtime', 'mktime', etc. now use much less stack space if ALL_STATE
is defined. (Thanks to Elliott Hughes for reporting the problem.)
'zic' no longer mishandles input when ignoring case in locales that
are not compatible with English, e.g., unibyte Turkish locales when
compiled with HAVE_GETTEXT.
Error diagnostics of 'zic' and 'yearistype' have been reworded so that
they no longer use ASCII '-' as if it were a dash.
'zic' now rejects output file names that contain '.' or '..' components.
(Thanks to Tim Parenti for reporting the problem.)
'zic -v' now warns about output file names that do not follow
POSIX rules, or that contain a digit or '.'. (Thanks to Arthur
David Olson for starting the ball rolling on this.)
Some lint has been removed when using GCC_DEBUG_FLAGS with GCC 4.9.0.
Changes affecting build procedure
'zic' no longer links in localtime.o and asctime.o, as they're not needed.
(Thanks to John Cochran.)
Changes affecting documentation and commentary
The 'Theory' file documents legacy names, the longstanding
exceptions to the POSIX-inspired file name rules.
The 'zic' documentation clarifies the role of time types when
interpreting dates. (Thanks to Arthur David Olson.)
Documentation and commentary now prefer UTF-8 to US-ASCII,
allowing the use of proper accents in foreign words and names.
Code and data have not changed because of this. (Thanks to
Garrett Wollman, Ian Abbott, and Guy Harris for helping to debug
this.)
Non-HTML documentation and commentary now use plain-text URLs instead of
HTML insertions, and are more consistent about bracketing URLs when they
are not already surrounded by white space. (Thanks to suggestions by
Steffen Nurpmeso.)
There is new commentary about Xujiahui Observatory, the five time-zone
project in China from 1918 to 1949, timekeeping in Japanese-occupied
Shanghai, and Tibet Time in the 1950s. The sharp-eyed can spot the
warlord Jin Shuren in the data.
Commentary about the coverage of each Russian zone has been standardized.
(Thanks to Tim Parenti.)
There is new commentary about contemporary timekeeping in Ethiopia.
Obsolete comments about a 2007 proposal for DST in Kuwait has been removed.
There is new commentary about time in Poland in 1919.
Proper credit has been given to DST inventor George Vernon Hudson.
Commentary about time in Metlakatla, AK and Resolute, NU has been
improved, with a new source for the former.
In zone.tab, Pacific/Easter no longer mentions Salas y Gómez, as it
is uninhabited.
Commentary about permanent Antarctic bases has been updated.
Several typos have been corrected. (Thanks to Tim Parenti for
contributing some of these fixes.)
tz-link.htm now mentions the JavaScript libraries Moment Timezone,
TimezoneJS.Date, Walltime-js, and Timezone. (Thanks to a heads-up
from Matt Johnson.) Also, it mentions the Go 'latlong' package.
(Thanks to a heads-up from Dirkjan Ochtman.)
The files usno1988, usno1989, usno1989a, usno1995, usno1997, and usno1998
have been removed. These obsolescent US Naval Observatory entries were no
longer helpful for maintenance. (Thanks to Tim Parenti for the suggestion.)
Release 2014e - 2014-06-12 21:53:52 -0700
Changes affecting near-future timestamps
Egypt's 2014 Ramadan-based transitions are June 26 and July 31 at 24:00.
(Thanks to Imed Chihi.) Guess that from 2015 on Egypt will temporarily
switch to standard time at 24:00 the last Thursday before Ramadan, and
back to DST at 00:00 the first Friday after Ramadan.
Similarly, Morocco's are June 28 at 03:00 and August 2 at 02:00. (Thanks
to Milamber Space Network.) Guess that from 2015 on Morocco will
temporarily switch to standard time at 03:00 the last Saturday before
Ramadan, and back to DST at 02:00 the first Saturday after Ramadan.
Changes affecting past timestamps
The abbreviation "MSM" (Moscow Midsummer Time) is now used instead of
"MSD" for Moscow's double daylight time in summer 1921. Also, a typo
"VLASST" has been repaired to be "VLAST" for Vladivostok summer time
in 1991. (Thanks to Hank W. for reporting the problems.)
Changes affecting commentary
tz-link.htm now cites RFC 7265 for jCal, mentions PTP and the
draft CalDAV extension, updates URLs for TSP, TZInfo, IATA, and
removes stale pointers to World Time Explorer and WORLDTIME.
Release 2014d - 2014-05-27 21:34:40 -0700
Changes affecting code
zic no longer generates files containing timestamps before the Big Bang.
This works around GNOME glib bug 878
<https://gitlab.gnome.org/GNOME/glib/issues/878>
(Thanks to Leonardo Chiquitto for reporting the bug, and to
Arthur David Olson and James Cloos for suggesting improvements to the fix.)
Changes affecting documentation
tz-link.htm now mentions GNOME.
Release 2014c - 2014-05-13 07:44:13 -0700
Changes affecting near-future timestamps
Egypt observes DST starting 2014-05-15 at 24:00.
(Thanks to Ahmad El-Dardiry and Gunther Vermier.)
Details have not been announced, except that DST will not be observed
during Ramadan. Guess that DST will stop during the same Ramadan dates as
Morocco, and that Egypt's future spring and fall transitions will be the
same as 2010 when it last observed DST, namely April's last Friday at
00:00 to September's last Thursday at 23:00 standard time. Also, guess
that Ramadan transitions will be at 00:00 standard time.
Changes affecting code
zic now generates transitions for minimum time values, eliminating guesswork
when handling low-valued timestamps. (Thanks to Arthur David Olson.)
Port to Cygwin sans glibc. (Thanks to Arthur David Olson.)
Changes affecting commentary and documentation
Remove now-confusing comment about Jordan. (Thanks to Oleksii Nochovnyi.)
Release 2014b - 2014-03-24 21:28:50 -0700
Changes affecting near-future timestamps
Crimea switches to Moscow time on 2014-03-30 at 02:00 local time.
(Thanks to Alexander Krivenyshev.) Move its zone.tab entry from UA to RU.
New entry for Troll station, Antarctica. (Thanks to Paul-Inge Flakstad and
Bengt-Inge Larsson.) This is currently an approximation; a better version
will require the zic and localtime fixes mentioned below, and the plan is
to wait for a while until at least the zic fixes propagate.
Changes affecting code
'zic' and 'localtime' no longer reject locations needing four transitions
per year for the foreseeable future. (Thanks to Andrew Main (Zefram).)
Also, 'zic' avoids some unlikely failures due to integer overflow.
Changes affecting build procedure
'make check' now detects Rule lines defined but never used.
The NZAQ rules, an instance of this problem, have been removed.
Changes affecting commentary and documentation
Fix Tuesday/Thursday typo in description of time in Israel.
(Thanks to Bert Katz via Pavel Kharitonov and Mike Frysinger.)
Microsoft Windows 8.1 doesn't support tz database names. (Thanks
to Donald MacQueen.) Instead, the Microsoft Windows Store app
library supports them.
Add comments about Johnston Island time in the 1960s.
(Thanks to Lyle McElhaney.)
Morocco's 2014 DST start will be as predicted.
(Thanks to Sebastien Willemijns.)
Release 2014a - 2014-03-07 23:30:29 -0800
Changes affecting near-future timestamps
Turkey begins DST on 2014-03-31, not 03-30. (Thanks to Faruk Pasin for
the heads-up, and to Tim Parenti for simplifying the update.)
Changes affecting past timestamps
Fiji ended DST on 2014-01-19 at 02:00, not the previously-scheduled 03:00.
(Thanks to Steffen Thorsen.)
Ukraine switched from Moscow to Eastern European time on 1990-07-01
(not 1992-01-01), and observed DST during the entire next winter.
(Thanks to Vladimir in Moscow via Alois Treindl.)
In 1988 Israel observed DST from 04-10 to 09-04, not 04-09 to 09-03.
(Thanks to Avigdor Finkelstein.)
Changes affecting code
A uninitialized-storage bug in 'localtime' has been fixed.
(Thanks to Logan Chien.)
Changes affecting the build procedure
The settings for 'make check_web' now default to Ubuntu 13.10.
Changes affecting commentary and documentation
The boundary of the US Pacific time zone is given more accurately.
(Thanks to Alan Mintz.)
Chile's 2014 DST will be as predicted. (Thanks to José Miguel Garrido.)
Paraguay's 2014 DST will be as predicted. (Thanks to Carlos Raúl Perasso.)
Better descriptions of countries with same time zone history as
Trinidad and Tobago since 1970. (Thanks to Alan Barrett for suggestion.)
Several changes affect tz-link.htm, the main web page.
Mention Time.is (thanks to Even Scharning) and WX-now (thanks to
David Braverman).
Mention xCal (Internet RFC 6321) and jCal.
Microsoft has some support for tz database names.
CLDR data formats include both XML and JSON.
Mention Maggiolo's map of solar vs standard time.
(Thanks to Arthur David Olson.)
Mention TZ4Net. (Thanks to Matt Johnson.)
Mention the timezone-olson Haskell package.
Mention zeitverschiebung.net. (Thanks to Martin Jäger.)
Remove moribund links to daylight-savings-time.info and to
Simple Timer + Clocks.
Update two links. (Thanks to Oscar van Vlijmen.)
Fix some formatting glitches, e.g., remove random newlines from
abbr elements' title attributes.
Release 2013i - 2013-12-17 07:25:23 -0800
Changes affecting near-future timestamps:
Jordan switches back to standard time at 00:00 on December 20, 2013.
The 2006-2011 transition schedule is planned to resume in 2014.
(Thanks to Steffen Thorsen.)
Changes affecting past timestamps:
In 2004, Cuba began DST on March 28, not April 4.
(Thanks to Steffen Thorsen.)
Changes affecting code
The compile-time flag NOSOLAR has been removed, as nowadays the
benefit of slightly shrinking runtime table size is outweighed by the
cost of disallowing potential future updates that exceed old limits.
Changes affecting documentation and commentary
The files solar87, solar88, and solar89 are no longer distributed.
They were a negative experiment - that is, a demonstration that
tz data can represent solar time only with some difficulty and error.
Their presence in the distribution caused confusion, as Riyadh
civil time was generally not solar time in those years.
tz-link.htm now mentions Noda Time. (Thanks to Matt Johnson.)
Release 2013h - 2013-10-25 15:32:32 -0700
Changes affecting current and future timestamps:
Libya has switched its UT offset back to +02 without DST, instead
of +01 with DST. (Thanks to Even Scharning.)
Western Sahara (Africa/El_Aaiun) uses Morocco's DST rules.
(Thanks to Gwillim Law.)
Changes affecting future timestamps:
Acre and (we guess) western Amazonas will switch from UT -04 to -05
on 2013-11-10. This affects America/Rio_Branco and America/Eirunepe.
(Thanks to Steffen Thorsen.)
Add entries for DST transitions in Morocco in the year 2038.
This avoids some year-2038 glitches introduced in 2013g.
(Thanks to Yoshito Umaoka for reporting the problem.)
Changes affecting API
The 'tzselect' command no longer requires the 'select' command,
and should now work with /bin/sh on more platforms. It also works
around a bug in BusyBox awk before version 1.21.0. (Thanks to
Patrick 'P. J.' McDermott and Alan Barrett.)
Changes affecting code
Fix localtime overflow bugs with 32-bit unsigned time_t.
zdump no longer assumes sscanf returns maximal values on overflow.
Changes affecting the build procedure
The builder can specify which programs to use, if any, instead of
'ar' and 'ranlib', and libtz.a is now built locally before being
installed. (Thanks to Michael Forney.)
A dependency typo in the 'zdump' rule has been fixed.
(Thanks to Andrew Paprocki.)
The Makefile has been simplified by assuming that 'mkdir -p' and 'cp -f'
work as specified by POSIX.2-1992 or later; this is portable nowadays.
'make clean' no longer removes 'leapseconds', since it's
host-independent and is part of the distribution.
The unused makefile macros TZCSRCS, TZDSRCS, DATESRCS have been removed.
Changes affecting documentation and commentary
tz-link.htm now mentions TC TIMEZONE's draft time zone service protocol
(thanks to Mike Douglass) and TimezoneJS.Date (thanks to Jim Fehrle).
Update URLs in tz-link page. Add URLs for Microsoft Windows, since
8.1 introduces tz support. Remove URLs for Tru64 and UnixWare (no
longer maintained) and for old advisories. SOFA now does C.
Release 2013g - 2013-09-30 21:08:26 -0700
Changes affecting current and near-future timestamps
Morocco now observes DST from the last Sunday in March to the last
Sunday in October, not April to September respectively. (Thanks
to Steffen Thorsen.)
Changes affecting 'zic'
'zic' now runs on platforms that lack both hard links and symlinks.
(Thanks to Theo Veenker for reporting the problem, for MinGW.)
Also, fix some bugs on platforms that lack hard links but have symlinks.
'zic -v' again warns that Asia/Tehran has no POSIX environment variable
to predict the far future, fixing a bug introduced in 2013e.
Changes affecting the build procedure
The 'leapseconds' file is again put into the tzdata tarball.
Also, 'leapseconds.awk', so tzdata is self-contained. (Thanks to
Matt Burgess and Ian Abbott.) The timestamps of these and other
dependent files in tarballs are adjusted more consistently.
Changes affecting documentation and commentary
The README file is now part of the data tarball as well as the code.
It now states that files are public domain unless otherwise specified.
(Thanks to Andrew Main (Zefram) for asking for clarifications.)
Its details about the 1989 release moved to a place of honor near
the end of NEWS.
Release 2013f - 2013-09-24 23:37:36 -0700
Changes affecting near-future timestamps
Tocantins will very likely not observe DST starting this spring.
(Thanks to Steffen Thorsen.)
Jordan will likely stay at UT +03 indefinitely, and will not fall
back this fall.
Palestine will fall back at 00:00, not 01:00. (Thanks to Steffen Thorsen.)
Changes affecting API
The types of the global variables 'timezone' and 'altzone' (if present)
have been changed back to 'long'. This is required for 'timezone'
by POSIX, and for 'altzone' by common practice, e.g., Solaris 11.
These variables were originally 'long' in the tz code, but were
mistakenly changed to 'time_t' in 1987; nobody reported the
incompatibility until now. The difference matters on x32, where
'long' is 32 bits and 'time_t' is 64. (Thanks to Elliott Hughes.)
Changes affecting the build procedure
Avoid long strings in leapseconds.awk to work around a mawk bug.
(Thanks to Cyril Baurand.)
Changes affecting documentation and commentary
New file 'NEWS' that contains release notes like this one.
Paraguay's law does not specify DST transition time; 00:00 is customary.
(Thanks to Waldemar Villamayor-Venialbo.)
Minor capitalization fixes.
Changes affecting version-control only
The experimental GitHub repository now contains annotated and
signed tags for recent releases, e.g., '2013e' for Release 2013e.
Releases are tagged starting with 2012e; earlier releases were
done differently, and tags would either not have a simple name or
not exactly match what was released.
'make set-timestamps' is now simpler and a bit more portable.
Release 2013e - 2013-09-19 23:50:04 -0700
Changes affecting near-future timestamps
This year Fiji will start DST on October 27, not October 20.
(Thanks to David Wheeler for the heads-up.) For now, guess that
Fiji will continue to spring forward the Sunday before the fourth
Monday in October.
Changes affecting current and future time zone abbreviations
Use WIB/WITA/WIT rather than WIT/CIT/EIT for alphabetic Indonesian
time zone abbreviations since 1932. (Thanks to George Ziegler,
Priyadi Iman Nurcahyo, Zakaria, Jason Grimes, Martin Pitt, and
Benny Lin.) This affects Asia/Dili, Asia/Jakarta, Asia/Jayapura,
Asia/Makassar, and Asia/Pontianak.
Use ART (UT -03, standard time), rather than WARST (also -03, but
daylight saving time) for San Luis, Argentina since 2009.
Changes affecting Godthåb timestamps after 2037 if version mismatch
Allow POSIX-like TZ strings where the transition time's hour can
range from -167 through 167, instead of the POSIX-required 0
through 24. E.g., TZ='FJT-12FJST,M10.3.1/146,M1.3.4/75' for the
new Fiji rules. This is a more-compact way to represent
far-future timestamps for America/Godthab, America/Santiago,
Antarctica/Palmer, Asia/Gaza, Asia/Hebron, Asia/Jerusalem,
Pacific/Easter, and Pacific/Fiji. Other zones are unaffected by
this change. (Derived from a suggestion by Arthur David Olson.)
Allow POSIX-like TZ strings where daylight saving time is in
effect all year. E.g., TZ='WART4WARST,J1/0,J365/25' for Western
Argentina Summer Time all year. This supports a more-compact way
to represent the 2013d data for America/Argentina/San_Luis.
Because of the change for San Luis noted above this change does not
affect the current data. (Thanks to Andrew Main (Zefram) for
suggestions that improved this change.)
Where these two TZ changes take effect, there is a minor extension
to the tz file format in that it allows new values for the
embedded TZ-format string, and the tz file format version number
has therefore been increased from 2 to 3 as a precaution.
Version-2-based client code should continue to work as before for
all timestamps before 2038. Existing version-2-based client code
(tzcode, GNU/Linux, Solaris) has been tested on version-3-format
files, and typically works in practice even for timestamps after
2037; the only known exception is America/Godthab.
Changes affecting timestamps before 1970
Pacific/Johnston is now a link to Pacific/Honolulu. This corrects
some errors before 1947.
Some zones have been turned into links, when they differ from existing
zones only in older data entries that were likely invented or that
differ only in LMT or transitions from LMT. These changes affect
only timestamps before 1943. The affected zones are:
Africa/Juba, America/Anguilla, America/Aruba, America/Dominica,
America/Grenada, America/Guadeloupe, America/Marigot,
America/Montserrat, America/St_Barthelemy, America/St_Kitts,
America/St_Lucia, America/St_Thomas, America/St_Vincent,
America/Tortola, and Europe/Vaduz. (Thanks to Alois Treindl for
confirming that the old Europe/Vaduz zone was wrong and the new
link is better for WWII-era times.)
Change Kingston Mean Time from -5:07:12 to -5:07:11. This affects
America/Cayman, America/Jamaica and America/Grand_Turk timestamps
from 1890 to 1912.
Change the UT offset of Bern Mean Time from 0:29:44 to 0:29:46.
This affects Europe/Zurich timestamps from 1853 to 1894. (Thanks
to Alois Treindl.)
Change the date of the circa-1850 Zurich transition from 1849-09-12
to 1853-07-16, overriding Shanks with data from Messerli about
postal and telegraph time in Switzerland.
Changes affecting time zone abbreviations before 1970
For Asia/Jakarta, use BMT (not JMT) for mean time from 1923 to 1932,
as Jakarta was called Batavia back then.
Changes affecting API
The 'zic' command now outputs a dummy transition when far-future
data can't be summarized using a TZ string, and uses a 402-year
window rather than a 400-year window. For the current data, this
affects only the Asia/Tehran file. It does not affect any of the
timestamps that this file represents, so zdump outputs the same
information as before. (Thanks to Andrew Main (Zefram).)
The 'date' command has a new '-r' option, which lets you specify
the integer time to display, a la FreeBSD.
The 'tzselect' command has two new options '-c' and '-n', which lets you
select a zone based on latitude and longitude.
The 'zic' command's '-v' option now warns about constructs that
require the new version-3 binary file format. (Thanks to Arthur
David Olson for the suggestion.)
Support for floating-point time_t has been removed.
It was always dicey, and POSIX no longer requires it.
(Thanks to Eric Blake for suggesting to the POSIX committee to
remove it, and thanks to Alan Barrett, Clive D.W. Feather, Andy
Heninger, Arthur David Olson, and Alois Treindl, for reporting
bugs and elucidating some of the corners of the old floating-point
implementation.)
The signatures of 'offtime', 'timeoff', and 'gtime' have been
changed back to the old practice of using 'long' to represent UT
offsets. This had been inadvertently and mistakenly changed to
'int_fast32_t'. (Thanks to Christos Zoulas.)
The code avoids undefined behavior on integer overflow in some
more places, including gmtime, localtime, mktime and zdump.
Changes affecting the zdump utility
zdump now outputs "UT" when referring to Universal Time, not "UTC".
"UTC" does not make sense for timestamps that predate the introduction
of UTC, whereas "UT", a more-generic term, does. (Thanks to Steve Allen
for clarifying UT vs UTC.)
Data changes affecting behavior of tzselect and similar programs
Country code BQ is now called the more-common name "Caribbean Netherlands"
rather than the more-official "Bonaire, St Eustatius & Saba".
Remove from zone.tab the names America/Montreal, America/Shiprock,
and Antarctica/South_Pole, as they are equivalent to existing
same-country-code zones for post-1970 timestamps. The data entries for
these names are unchanged, so the names continue to work as before.
Changes affecting code internals
zic -c now runs way faster on 64-bit hosts when given large numbers.
zic now uses vfprintf to avoid allocating and freeing some memory.
tzselect now computes the list of continents from the data,
rather than have it hard-coded.
Minor changes pacify GCC 4.7.3 and GCC 4.8.1.
Changes affecting the build procedure
The 'leapseconds' file is now generated automatically from a
new file 'leap-seconds.list', which is a copy of
<ftp://ftp.nist.gov/pub/time/leap-seconds.list>
A new source file 'leapseconds.awk' implements this.
The goal is simplification of the future maintenance of 'leapseconds'.
When building the 'posix' or 'right' subdirectories, if the
subdirectory would be a copy of the default subdirectory, it is
now made a symbolic link if that is supported. This saves about
2 MB of file system space.
The links America/Shiprock and Antarctica/South_Pole have been
moved to the 'backward' file. This affects only nondefault builds
that omit 'backward'.
Changes affecting version-control only
.gitignore now ignores 'date'.
Changes affecting documentation and commentary
Changes to the 'tzfile' man page
It now mentions that the binary file format may be extended in
future versions by appending data.
It now refers to the 'zdump' and 'zic' man pages.
Changes to the 'zic' man page
It lists conditions that elicit a warning with '-v'.
It says that the behavior is unspecified when duplicate names
are given, or if the source of one link is the target of another.
Its examples are updated to match the latest data.
The definition of white space has been clarified slightly.
(Thanks to Michael Deckers.)
Changes to the 'Theory' file
There is a new section about the accuracy of the tz database,
describing the many ways that errors can creep in, and
explaining why so many of the pre-1970 timestamps are wrong or
misleading (thanks to Steve Allen, Lester Caine, and Garrett
Wollman for discussions that contributed to this).
The 'Theory' file describes LMT better (this follows a
suggestion by Guy Harris).
It refers to the 2013 edition of POSIX rather than the 2004 edition.
It's mentioned that excluding 'backward' should not affect the
other data, and it suggests at least one zone.tab name per
inhabited country (thanks to Stephen Colebourne).
Some longstanding restrictions on names are documented, e.g.,
'America/New_York' precludes 'America/New_York/Bronx'.
It gives more reasons for the 1970 cutoff.
It now mentions which time_t variants are supported, such as
signed integer time_t. (Thanks to Paul Goyette for reporting
typos in an experimental version of this change.)
(Thanks to Philip Newton for correcting typos in these changes.)
Documentation and commentary is more careful to distinguish UT in
general from UTC in particular. (Thanks to Steve Allen.)
Add a better source for the Zurich 1894 transition.
(Thanks to Pierre-Yves Berger.)
Update shapefile citations in tz-link.htm. (Thanks to Guy Harris.)
Release 2013d - 2013-07-05 07:38:01 -0700
Changes affecting future timestamps:
Morocco's midsummer transitions this year are July 7 and August 10,
not July 9 and August 8. (Thanks to Andrew Paprocki.)
Israel now falls back on the last Sunday of October.
(Thanks to Ephraim Silverberg.)
Changes affecting past timestamps:
Specify Jerusalem's location more precisely; this changes the pre-1880
times by 2 s.
Changing affecting metadata only:
Fix typos in the entries for country codes BQ and SX.
Changes affecting code:
Rework the code to fix a bug with handling Australia/Macquarie on
32-bit hosts (thanks to Arthur David Olson).
Port to platforms like NetBSD, where time_t can be wider than long.
Add support for testing time_t types other than the system's.
Run 'make check_time_t_alternatives' to try this out.
Currently, the tests fail for unsigned time_t;
this should get fixed at some point.
Changes affecting documentation and commentary:
Deemphasize the significance of national borders.
Update the zdump man page.
Remove obsolete NOID comment (thanks to Denis Excoffier).
Update several URLs and comments in the web pages.
Spelling fixes (thanks to Kevin Lyda and Jonathan Leffler).
Update URL for CLDR Zone->Tzid table (thanks to Yoshito Umaoka).
Release 2013c - 2013-04-19 16:17:40 -0700
Changes affecting current and future timestamps:
Palestine observed DST starting March 29, 2013. (Thanks to
Steffen Thorsen.) From 2013 on, Gaza and Hebron both observe DST,
with the predicted rules being the last Thursday in March at 24:00
to the first Friday on or after September 21 at 01:00.
Assume that the recent change to Paraguay's DST rules is permanent,
by moving the end of DST to the 4th Sunday in March every year.
(Thanks to Carlos Raúl Perasso.)
Changes affecting past timestamps:
Fix some historical data for Palestine to agree with that of
timeanddate.com, as follows:
The spring 2008 change in Gaza and Hebron was on 00:00 Mar 28, not
00:00 Apr 1.
The fall 2009 change in Gaza and Hebron on Sep 4 was at 01:00, not
02:00.
The spring 2010 change in Hebron was 00:00 Mar 26, not 00:01 Mar 27.
The spring 2011 change in Gaza was 00:01 Apr 1, not 12:01 Apr 2.
The spring 2011 change in Hebron on Apr 1 was at 00:01, not 12:01.
The fall 2011 change in Hebron on Sep 30 was at 00:00, not 03:00.
Fix times of habitation for Macquarie to agree with the Tasmania
Parks & Wildlife Service history, which indicates that permanent
habitation was 1899-1919 and 1948 on.
Changing affecting metadata only:
Macquarie Island is politically part of Australia, not Antarctica.
(Thanks to Tobias Conradi.)
Sort Macquarie more-consistently with other parts of Australia.
(Thanks to Tim Parenti.)
Release 2013b - 2013-03-10 22:33:40 -0700
Changes affecting current and future timestamps:
Haiti uses US daylight-saving rules this year, and presumably future years.
This changes timestamps starting today. (Thanks to Steffen Thorsen.)
Paraguay will end DST on March 24 this year.
(Thanks to Steffen Thorsen.) For now, assume it's just this year.
Morocco does not observe DST during Ramadan;
try to predict Ramadan in Morocco as best we can.
(Thanks to Erik Homoet for the heads-up.)
Changes affecting commentary:
Update URLs in tz-link page. Add URLs for webOS, BB10, iOS.
Update URL for Solaris. Mention Internet RFC 6557.
Update Internet RFCs 2445->5545, 2822->5322.
Switch from FTP to HTTP for Internet RFCs.
Release 2013a - 2013-02-27 09:20:35 -0800
Change affecting binary data format:
The zone offset at the end of version-2-format zone files is now
allowed to be 24:00, as per POSIX.1-2008. (Thanks to Arthur David Olson.)
Changes affecting current and future timestamps:
Chile's 2013 rules, and we guess rules for 2014 and later, will be
the same as 2012, namely Apr Sun>=23 03:00 UTC to Sep Sun>=2 04:00 UTC.
(Thanks to Steffen Thorsen and Robert Elz.)
New Zones Asia/Khandyga, Asia/Ust-Nera, Europe/Busingen.
(Thanks to Tobias Conradi and Arthur David Olson.)
Many changes affect historical timestamps before 1940.
These were deduced from: Milne J. Civil time. Geogr J. 1899
Feb;13(2):173-94 <https://www.jstor.org/stable/1774359>.
Changes affecting the code:
Fix zic bug that mishandled Egypt's 2010 changes (this also affected
the data). (Thanks to Arthur David Olson.)
Fix localtime bug when time_t is unsigned and data files were generated
by a signed time_t system. (Thanks to Doug Bailey for reporting and
to Arthur David Olson for fixing.)
Allow the email address for bug reports to be set by the packager.
The default is tz@iana.org, as before. (Thanks to Joseph S. Myers.)
Update HTML checking to be compatible with Ubuntu 12.10.
Check that files are a safe subset of ASCII. At some point we may
relax this requirement to a safe subset of UTF-8. Without the
check, some non-UTF-8 encodings were leaking into the distribution.
Commentary changes:
Restore a comment about copyright notices that was inadvertently deleted.
(Thanks to Arthur David Olson.)
Improve the commentary about which districts observe what times
in Russia. (Thanks to Oscar van Vlijmen and Arthur David Olson.)
Add web page links to tz.js.
Add "Run by the Monkeys" to tz-art. (Thanks to Arthur David Olson.)
Release 2012j - 2012-11-12 18:34:49 -0800
Libya moved to CET this weekend, but with DST planned next year.
(Thanks to Even Scharning, Steffen Thorsen, and Tim Parenti.)
Signatures now have the extension .asc, not .sign, as that's more
standard. (Thanks to Phil Pennock.)
The output of 'zdump --version', and of 'zic --version', now
uses a format that is more typical for --version.
(Thanks to Joseph S. Myers.)
The output of 'tzselect --help', 'zdump --help', and 'zic --help'
now uses tz@iana.org rather than the old elsie address.
zic -v now complains about abbreviations that are less than 3
or more than 6 characters, as per Posix. Formerly, it checked
for abbreviations that were more than 3.
'make public' no longer puts its temporary directory under /tmp,
and uses the just-built zic rather than the system zic.
Various fixes to documentation and commentary.
Release 2012i - 2012-11-03 12:57:09 -0700
Cuba switches from DST tomorrow at 01:00. (Thanks to Steffen Thorsen.)
Linker flags can now be specified via LDFLAGS.
AWK now defaults to 'awk', not 'nawk'.
The shell in tzselect now defaults to /bin/bash, but this can
be overridden by specifying KSHELL.
The main web page now mentions the unofficial GitHub repository.
(Thanks to Mike Frysinger.)
Tarball signatures can now be built by running 'make signatures'.
There are also new makefile rules 'tarballs', 'check_public', and
separate makefile rules for each tarball and signature file.
A few makefile rules are now more portable to strict POSIX.
The main web page now lists the canonical IANA URL.
Release 2012h - 2012-10-26 22:49:10 -0700
Bahia no longer has DST. (Thanks to Kelley Cook.)
Tocantins has DST. (Thanks to Rodrigo Severo.)
Israel has new DST rules next year. (Thanks to Ephraim Silverberg.)
Jordan stays on DST this winter. (Thanks to Steffen Thorsen.)
Web page updates.
More C modernization, except that at Arthur David Olson's suggestion
the instances of 'register' were kept.
Release 2012g - 2012-10-17 20:59:45 -0700
Samoa fall 2012 and later. (Thanks to Nicholas Pereira and Robert Elz.)
Palestine fall 2012. (Thanks to Steffen Thorsen.)
Assume C89.
To attack the version-number problem, this release ships the file
'Makefile' (which contains the release number) in both the tzcode and
the tzdata tarballs. The two Makefiles are identical, and should be
identical in any matching pair of tarballs, so it shouldn't matter
which order you extract the tarballs. Perhaps we can come up with a
better version-number scheme at some point; this scheme does have the
virtue of not adding more files.
Release 2012f - 2012-09-12 23:17:03 -0700
* australasia (Pacific/Fiji): Fiji DST is October 21 through January
20 this year. (Thanks to Steffen Thorsen.)
Release 2012e - 2012-08-02 20:44:55 -0700
* australasia (Pacific/Fakaofo): Tokelau is UT +13, not +14.
(Thanks to Steffen Thorsen.)
* Use a single version number for both code and data.
* .gitignore: New file.
* Remove trailing white space.
Release code2012c-data2012d - 2012-07-19 16:35:33 -0700
Changes for Morocco's timestamps, which take effect in a couple of
hours, along with infrastructure changes to accommodate how the tz
code and data are released on IANA.
Release data2012c - 2012-03-27 12:17:25 -0400
africa
Summer time changes for Morocco (to start late April 2012)
asia
Changes for 2012 for Gaza & the West Bank (Hebron) and Syria
northamerica
Haiti following US/Canada rules for 2012 (and we're assuming,
for now anyway, for the future).
Release 2012b - 2012-03-02 12:29:15 +0700
There is just one change to tzcode2012b (compared with 2012a):
the Makefile that was accidentally included with 2012a has been
replaced with the version that should have been there, which is
identical with the previous version (from tzcode2011i).
There are just two changes in tzdata2012b compared with 2012a.
Most significantly, summer time in Cuba has been delayed 3 weeks
(now starts April 1 rather than March 11). Since Mar 11 (the old start
date, as listed in 2012a) is just a little over a week away, this
change is urgent.
Less importantly, an excess tab in one of the changes in zone.tab
in 2012a has been removed.
Release 2012a - 2012-03-01 18:28:10 +0700
The changes in tzcode2012a (compared to the previous version, 2011i)
are entirely to the README and tz-art.htm and tz-link.htm files, if
none of those concern you, you can ignore the code update. The changes
reflect the changed addresses for the mailing list and the code and
data distribution points & methods (and a link to DateTime::TimeZone::Tzfile
has been added to tz-link.htm).
In tzdata2012a (compared to the previous release, which was 2011n)
the major changes are:
Chile 2011/2012 and 2012/2013 summer time date adjustments.
Falkland Islands onto permanent summer time (we're assuming for the
foreseeable future, though 2012 is all we're fairly certain of.)
Armenia has abolished Summer Time.
Tokelau jumped the International Date Line back last December
(just the same as their near neighbour, Samoa).
America/Creston is a new zone for a small area of British Columbia
There will be a leapsecond 2012-06-30 23:59:60 UTC.
Other minor changes are:
Corrections to 1918 Canadian summer time end dates.
Updated URL for UK time zone history (in comments)
A few typos in Le Corre's list of free French place names (comments)
Release data2011n - 2011-10-30 14:57:54 +0700
There are three changes of note - most urgently, Cuba (America/Havana)
has extended summer time by two weeks, now to end on Nov 13, rather than
the (already past) Oct 30. Second, the Pridnestrovian Moldavian Republic
(Europe/Tiraspol) decided not to split from the rest of Moldova after
all, and consequently that zone has been removed (again) and reinstated
in the "backward" file as a link to Europe/Chisinau. And third, the
end date for Fiji's summer time this summer was moved forward from the
earlier planned Feb 26, to Jan 22.
Apart from that, Moldova (MD) returns to a single entry in zone.tab
(and the incorrect syntax that was in the 2011m version of that file
is so fixed - it would have been fixed in a different way had this
change not happened - that's the "missing" sccs version id).
Release data2011m - 2011-10-24 21:42:16 +0700
In particular, the typos in comments in the data (2011-11-17 should have
been 2011-10-17 as Alan Barrett noted, and spelling of Tiraspol that
Tim Parenti noted) have been fixed, and the change for Ukraine has been
made in all 4 Ukrainian zones, rather than just Kiev (again, thanks to
Tim Parenti, and also Denys Gavrysh)
In addition, I added Europe/Tiraspol to zone.tab.
This time, all the files have new version numbers... (including the files
otherwise unchanged in 2011m that were changed in 2011l but didn't get new
version numbers there...)
Release data2011l - 2011-10-10 11:15:43 +0700
There are just 2 changes that cause different generated tzdata files from
zic, to Asia/Hebron and Pacific/Fiji - the possible change for Bahia, Brazil
is included, but commented out. Compared with the diff I sent out last week,
this version also includes attributions for the sources for the changes
(in much the same format as ado used, but the html tags have not been
checked, verified, or used in any way at all, so if there are errors there,
please let me know.)
Release data2011k - 2011-09-20 17:54:03 -0400
[not summarized]
Release data2011j - 2011-09-12 09:22:49 -0400
(contemporary changes for Samoa; past changes for Kenya, Uganda, and
Tanzania); there are also two spelling corrections to comments in
the australasia file (with thanks to Christos Zoulas).
Release 2011i - 2011-08-29 05:56:32 -0400
[not summarized]
Release data2011h - 2011-06-15 18:41:48 -0400
Russia and Curaçao changes
Release 2011g - 2011-04-25 09:07:22 -0400
update the rules for Egypt to reflect its abandonment of DST this year
Release 2011f - 2011-04-06 17:14:53 -0400
[not summarized]
Release 2011e - 2011-03-31 16:04:38 -0400
Morocco, Chile, and tz-link changes
Release 2011d - 2011-03-14 09:18:01 -0400
changes that impact present-day timestamps in Cuba, Samoa, and Turkey
Release 2011c - 2011-03-07 09:30:09 -0500
These do affect current timestamps in Chile and Annette Island, Canada.
Release 2011b - 2011-02-07 08:44:50 -0500
[not summarized]
Release 2011a - 2011-01-24 10:30:16 -0500
[not summarized]
Release data2010o - 2010-11-01 09:18:23 -0400
change to the end of DST in Fiji in 2011
Release 2010n - 2010-10-25 08:19:17 -0400
[not summarized]
Release 2010m - 2010-09-27 09:24:48 -0400
Hong Kong, Vostok, and zic.c changes
Release 2010l - 2010-08-16 06:57:25 -0400
[not summarized]
Release 2010k - 2010-07-26 10:42:27 -0400
[not summarized]
Release 2010j - 2010-05-10 09:07:48 -0400
changes for Bahía de Banderas and for version naming
Release data2010i - 2010-04-16 18:50:45 -0400
the end of DST in Morocco on 2010-08-08
Release data2010h - 2010-04-05 09:58:56 -0400
[not summarized]
Release data2010g - 2010-03-24 11:14:53 -0400
[not summarized]
Release 2010f - 2010-03-22 09:45:46 -0400
[not summarized]
Release data2010e - 2010-03-08 14:24:27 -0500
corrects the Dhaka bug found by Danvin Ruangchan
Release data2010d - 2010-03-06 07:26:01 -0500
[not summarized]
Release 2010c - 2010-03-01 09:20:58 -0500
changes including KRE's suggestion for earlier initialization of
"goahead" and "goback" structure elements
Release code2010a - 2010-02-16 10:40:04 -0500
[not summarized]
Release data2010b - 2010-01-20 12:37:01 -0500
Mexico changes
Release data2010a - 2010-01-18 08:30:04 -0500
changes to Dhaka
Release data2009u - 2009-12-26 08:32:28 -0500
changes to DST in Bangladesh
Release 2009t - 2009-12-21 13:24:27 -0500
[not summarized]
Release data2009s - 2009-11-14 10:26:32 -0500
(cosmetic) Antarctica change and the DST-in-Fiji-in-2009-and-2010 change
Release 2009r - 2009-11-09 10:10:31 -0500
"antarctica" and "tz-link.htm" changes
Release 2009q - 2009-11-02 09:12:40 -0500
with two corrections as reported by Eric Muller and Philip Newton
Release data2009p - 2009-10-23 15:05:27 -0400
Argentina (including San Luis) changes (with the correction from
Mariano Absatz)
Release data2009o - 2009-10-14 16:49:38 -0400
Samoa (commentary only), Pakistan, and Bangladesh changes
Release data2009n - 2009-09-22 15:13:38 -0400
added commentary for Argentina and a change to the end of DST in
2009 in Pakistan
Release data2009m - 2009-09-03 10:23:43 -0400
Samoa and Palestine changes
Release data2009l - 2009-08-14 09:13:07 -0400
Samoa (comments only) and Egypt
Release 2009k - 2009-07-20 09:46:08 -0400
[not summarized]
Release data2009j - 2009-06-15 06:43:59 -0400
Bangladesh change (with a short turnaround since the DST change is
impending)
Release 2009i - 2009-06-08 09:21:22 -0400
updating for DST in Bangladesh this year
Release 2009h - 2009-05-26 09:19:14 -0400
[not summarized]
Release data2009g - 2009-04-20 16:34:07 -0400
Cairo
Release data2009f - 2009-04-10 11:00:52 -0400
correct DST in Pakistan
Release 2009e - 2009-04-06 09:08:11 -0400
[not summarized]
Release 2009d - 2009-03-23 09:38:12 -0400
Morocco, Tunisia, Argentina, and American Astronomical Society changes
Release data2009c - 2009-03-16 09:47:51 -0400
change to the start of Cuban DST
Release 2009b - 2009-02-09 11:15:22 -0500
[not summarized]
Release 2009a - 2009-01-21 10:09:39 -0500
[not summarized]
Release data2008i - 2008-10-21 12:10:25 -0400
southamerica and zone.tab files, with Argentina DST rule changes and
United States zone reordering and recommenting
Release 2008h - 2008-10-13 07:33:56 -0400
[not summarized]
Release 2008g - 2008-10-06 09:03:18 -0400
Fix a broken HTML anchor and update Brazil's DST transitions;
there's also a slight reordering of information in tz-art.htm.
Release data2008f - 2008-09-09 22:33:26 -0400
[not summarized]
Release 2008e - 2008-07-28 14:11:17 -0400
changes by Arthur David Olson and Jesper Nørgaard Welen
Release data2008d - 2008-07-07 09:51:38 -0400
changes by Arthur David Olson, Paul Eggert, and Rodrigo Severo
Release data2008c - 2008-05-19 17:48:03 -0400
Pakistan, Morocco, and Mongolia
Release data2008b - 2008-03-24 08:30:59 -0400
including renaming Asia/Calcutta to Asia/Kolkata, with a backward
link provided
Release 2008a - 2008-03-08 05:42:16 -0500
[not summarized]
Release 2007k - 2007-12-31 10:25:22 -0500
most importantly, changes to the "southamerica" file based on
Argentina's readoption of daylight saving time
Release 2007j - 2007-12-03 09:51:01 -0500
1. eliminate the "P" (parameter) macro;
2. the "noncontroversial" changes circulated on the time zone
mailing list (less the changes to "logwtmp.c");
3. eliminate "too many transition" errors when "min" is used in time
zone rules;
4. changes by Paul Eggert (including updated information for Venezuela).
Release data2007i - 2007-10-30 10:28:11 -0400
changes for Cuba and Syria
Release 2007h - 2007-10-01 10:05:51 -0400
changes by Paul Eggert, as well as an updated link to the ICU
project in tz-link.htm
Release 2007g - 2007-08-20 10:47:59 -0400
changes by Paul Eggert
The "leapseconds" file has been updated to incorporate the most
recent International Earth Rotation and Reference Systems Service
(IERS) bulletin.
There's an addition to tz-art.htm regarding the television show "Medium".
Release 2007f - 2007-05-07 10:46:46 -0400
changes by Paul Eggert (including Haiti, Turks and Caicos, and New
Zealand)
changes to zic.c to allow hour values greater than 24 (along with
Paul's improved time value overflow checking)
Release 2007e - 2007-04-02 10:11:52 -0400
Syria and Honduras changes by Paul Eggert
zic.c variable renaming changes by Arthur David Olson
Release 2007d - 2007-03-20 08:48:30 -0400
changes by Paul Eggert
the elimination of white space at the ends of lines
Release 2007c - 2007-02-26 09:09:37 -0500
changes by Paul Eggert
Release 2007b - 2007-02-12 09:34:20 -0500
Paul Eggert's proposed change to the quotation handling logic in zic.c.
changes to the commentary in "leapseconds" reflecting the IERS
announcement that there is to be no positive leap second at the end
of June 2007.
Release 2007a - 2007-01-08 12:28:29 -0500
changes by Paul Eggert
Derick Rethan's Asmara change
Oscar van Vlijmen's Easter Island local mean time change
symbolic link changes
Release 2006p - 2006-11-27 08:54:27 -0500
changes by Paul Eggert
Release 2006o - 2006-11-06 09:18:07 -0500
changes by Paul Eggert
Release 2006n - 2006-10-10 11:32:06 -0400
changes by Paul Eggert
Release 2006m - 2006-10-02 15:32:35 -0400
changes for Uruguay, Palestine, and Egypt by Paul Eggert
(minimalist) changes to zic.8 to clarify "until" information
Release data2006l - 2006-09-18 12:58:11 -0400
Paul's best-effort work on this coming weekend's Egypt time change
Release 2006k - 2006-08-28 12:19:09 -0400
changes by Paul Eggert
Release 2006j - 2006-08-21 09:56:32 -0400
changes by Paul Eggert
Release code2006i - 2006-08-07 12:30:55 -0400
localtime.c fixes
Ken Pizzini's conversion script
Release code2006h - 2006-07-24 09:19:37 -0400
adds public domain notices to four files
includes a fix for transition times being off by a second
adds a new recording to the "arts" file (information courtesy Colin Bowern)
Release 2006g - 2006-05-08 17:18:09 -0400
northamerica changes by Paul Eggert
Release 2006f - 2006-05-01 11:46:00 -0400
a missing version number problem is fixed (with thanks to Bradley
White for catching the problem)
Release 2006d - 2006-04-17 14:33:43 -0400
changes by Paul Eggert
added new items to tz-arts.htm that were found by Paul
Release 2006c - 2006-04-03 10:09:32 -0400
two sets of data changes by Paul Eggert
a fencepost error fix in zic.c
changes to zic.c and the "europe" file to minimize differences
between output produced by the old 32-bit zic and the new 64-bit
version
Release 2006b - 2006-02-20 10:08:18 -0500
[tz32code2006b + tz64code2006b + tzdata2006b]
64-bit code
All SCCS IDs were bumped to "8.1" for this release.
Release 2006a - 2006-01-30 08:59:31 -0500
changes by Paul Eggert (in particular, Indiana time zone moves)
an addition to the zic manual page to describe how special-case
transitions are handled
Release 2005r - 2005-12-27 09:27:13 -0500
Canadian changes by Paul Eggert
They also add "<pre>" directives to time zone data files and reflect
changes to warning message logic in "zdump.c" (but with calls to
"gettext" kept unbundled at the suggestion of Ken Pizzini).
Release 2005q - 2005-12-13 09:17:09 -0500
Nothing earth-shaking here:
1. Electronic mail addresses have been removed.
2. Casts of the return value of exit have been removed.
3. Casts of the argument of is.* macros have been added.
4. Indentation in one section of zic.c has been fixed.
5. References to dead URLs in the data files have been dealt with.
Release 2005p - 2005-12-05 10:30:53 -0500
"systemv", "tz-link.htm", and "zdump.c" changes
(less the casts of arguments to the is* macros)
Release 2005o - 2005-11-28 10:55:26 -0500
Georgia, Cuba, Nicaragua, and Jordan changes by Paul Eggert
zdump.c lint fixes by Arthur David Olson
Release 2005n - 2005-10-03 09:44:09 -0400
changes by Paul Eggert (both the Uruguay changes and the Kyrgyzstan
et al. changes)
Release 2005m - 2005-08-29 12:15:40 -0400
changes by Paul Eggert (with a small tweak to the tz-art change)
a declaration of an unused variable has been removed from zdump.c
Release 2005l - 2005-08-22 12:06:39 -0400
changes by Paul Eggert
overflow/underflow checks by Arthur David Olson, minus changes to
the "Theory" file about the pending addition of 64-bit data (I grow
less confident of the changes being accepted with each passing day,
and the changes no longer increase the data files nine-fold--there's
less than a doubling in size by my local Sun's reckoning)
Release 2005k - 2005-07-14 14:14:24 -0400
The "leapseconds" file has been edited to reflect the recently
announced leap second at the end of 2005.
I've also deleted electronic mail addresses from the files as an
anti-spam measure.
Release 2005j - 2005-06-13 14:34:13 -0400
These reflect changes to limit the length of time zone abbreviations
and the characters used in those abbreviations.
There are also changes to handle POSIX-style "quoted" timezone
environment variables.
The changes were circulated on the time zone mailing list; the only
change since then was the removal of a couple of minimum-length of
abbreviation checks.
Release data2005i - 2005-04-21 15:04:16 -0400
changes (most importantly to Nicaragua and Haiti) by Paul Eggert
Release 2005h - 2005-04-04 11:24:47 -0400
changes by Paul Eggert
minor changes to Makefile and zdump.c to produce more useful output
when doing a "make typecheck"
Release 2005g - 2005-03-14 10:11:21 -0500
changes by Paul Eggert (a change to current DST rules in Uruguay and
an update to a link to time zone software)
Release 2005f - 2005-03-01 08:45:32 -0500
data and documentation changes by Paul Eggert
Release 2005e - 2005-02-10 15:59:44 -0500
[not summarized]
Release code2005d - 2005-01-31 09:21:47 -0500
make zic complain about links to links if the -v flag is used
have "make public" do more code checking
add an include to "localtime.c" for the benefit of gcc systems
Release 2005c - 2005-01-17 18:36:29 -0500
get better results when mktime runs on a system where time_t is double
changes to the data files (most importantly to Paraguay)
Release 2005b - 2005-01-10 09:19:54 -0500
Get localtime and gmtime working on systems with exotic time_t types.
Update the leap second commentary in the "leapseconds" file.
Release 2005a - 2005-01-01 13:13:44 -0500
[not summarized]
Release code2004i - 2004-12-14 13:42:58 -0500
Deal with systems where time_t is unsigned.
Release code2004h - 2004-12-07 11:40:18 -0500
64-bit-time_t changes
Release 2004g - 2004-11-02 09:06:01 -0500
update to Cuba (taking effect this weekend)
other changes by Paul Eggert
correction of the spelling of Oslo
changed versions of difftime.c and private.h
Release code2004f - 2004-10-21 10:25:22 -0400
Cope with wide-ranging tm_year values.
Release 2004e - 2004-10-11 14:47:21 -0400
Brazil/Argentina/Israel changes by Paul Eggert
changes to tz-link.htm by Paul
one small fix to Makefile
Release 2004d - 2004-09-22 08:27:29 -0400
Avoid overflow problems when TM_YEAR_BASE is added to an integer.
Release 2004c - 2004-08-11 12:06:26 -0400
asctime-related changes
(variants of) some of the documentation changes suggested by Paul Eggert
Release 2004b - 2004-07-19 14:33:35 -0400
data changes by Paul Eggert - most importantly, updates for Argentina
Release 2004a - 2004-05-27 12:00:47 -0400
changes by Paul Eggert
Handle DST transitions that occur at the end of a month in some
years but at the start of the following month in other years.
Add a copy of the correspondence that's the basis for claims about
DST in the Navajo Nation.
Release 2003e - 2003-12-15 09:36:47 -0500
changes by Arthur David Olson (primarily code changes)
changes by Paul Eggert (primarily data changes)
minor changes to "Makefile" and "northamerica" (in the latter case,
optimization of the "Toronto" rules)
Release 2003d - 2003-10-06 09:34:44 -0400
changes by Paul Eggert
Release 2003c - 2003-09-16 10:47:05 -0400
Fix bad returns in zic.c's inleap function.
Thanks to Bradley White for catching the problem!
Release 2003b - 2003-09-16 07:13:44 -0400
Add a "--version" option (and documentation) to the zic and zdump commands.
changes to overflow/underflow checking in zic
a localtime typo fix.
Update the leapseconds and tz-art.htm files.
Release 2003a - 2003-03-24 09:30:54 -0500
changes by Paul Eggert
a few additions and modifications to the tz-art.htm file
Release 2002d - 2002-10-15 13:12:42 -0400
changes by Paul Eggert, less the "Britain (UK)" change in iso3166.tab
There's also a new time zone quote in "tz-art.htm".
Release 2002c - 2002-04-04 11:55:20 -0500
changes by Paul Eggert
Change zic.c to avoid creating symlinks to files that don't exist.
Release 2002b - 2002-01-28 12:56:03 -0500
[These change notes are for Release 2002a, which was corrupted.
2002b was a corrected version of 2002a.]
changes by Paul Eggert
Update the "leapseconds" file to note that there'll be no leap
second at the end of June, 2002.
Change "zic.c" to deal with a problem in handling the "Asia/Bishkek" zone.
Change to "difftime.c" to avoid sizeof problems.
Release 2001d - 2001-10-09 13:31:32 -0400
changes by Paul Eggert
Release 2001c - 2001-06-05 13:59:55 -0400
changes by Paul Eggert and Andrew Brown
Release 2001b - 2001-04-05 16:44:38 -0400
changes by Paul Eggert (modulo jnorgard's typo fix)
tz-art.htm has been HTMLified.
Release 2001a - 2001-03-13 12:57:44 -0500
changes by Paul Eggert
An addition to the "leapseconds" file: comments with the text of the
latest IERS leap second notice.
Trailing white space has been removed from data file lines, and
repeated spaces in "Rule Jordan" lines in the "asia" file have been
converted to tabs.
Release 2000h - 2000-12-14 15:33:38 -0500
changes by Paul Eggert
one typo fix in the "art" file
With providence, this is the last update of the millennium.
Release 2000g - 2000-10-10 11:35:22 -0400
changes by Paul Eggert
correction of John Mackin's name submitted by Robert Elz
Garry Shandling's Daylight Saving Time joke (!?!) from the recent
Emmy Awards broadcast.
Release 2000f - 2000-08-10 09:31:58 -0400
changes by Paul Eggert
Added information in "tz-art.htm" on a Seinfeld reference to DST.
Error checking and messages in the "yearistype" script have been
improved.
Release 2000e - 2000-07-31 09:27:54 -0400
data changes by Paul Eggert
a change to the default value of the defined constant HAVE_STRERROR
the addition of a Dave Barry quote on DST to the tz-arts file
Release 2000d - 2000-04-20 15:43:04 -0400
changes to the documentation and code of strftime for C99 conformance
a bug fix for date.c
These are based on (though modified from) changes by Paul Eggert.
Release 2000c - 2000-03-04 10:31:43 -0500
changes by Paul Eggert
Release 2000b - 2000-02-21 12:16:29 -0500
changes by Paul Eggert and Joseph Myers
modest tweaks to the tz-art.htm and tz-link.htm files
Release 2000a - 2000-01-18 09:21:26 -0500
changes by Paul Eggert
The two hypertext documents have also been renamed.
Release code1999i-data1999j - 1999-11-15 18:43:22 -0500
Paul Eggert's changes
additions to the "zic" manual page and the "Arts.htm" file
Release code1999h-data1999i - 1999-11-08 14:55:21 -0500
[not summarized]
Release data1999h - 1999-10-07 03:50:29 -0400
changes by Paul Eggert to "europe" (most importantly, fixing
Lithuania and Estonia)
Release 1999g - 1999-09-28 11:06:18 -0400
data changes by Paul Eggert (most importantly, the change for
Lebanon that buys correctness for this coming Sunday)
The "code" file contains changes to "Makefile" and "checktab.awk" to
allow better checking of time zone files before they are published.
Release 1999f - 1999-09-23 09:48:14 -0400
changes by Arthur David Olson and Paul Eggert
Release 1999e - 1999-08-17 15:20:54 -0400
changes circulated by Paul Eggert, although the change to handling
of DST-specifying timezone names has been commented out for now
(search for "XXX" in "localtime.c" for details). These files also
do not make any changes to the start of DST in Brazil.
In addition to Paul's changes, there are updates to "Arts.htm" and
cleanups of URLs.
Release 1999d - 1999-03-30 11:31:07 -0500
changes by Paul Eggert
The Makefile's "make public" rule has also been changed to do a test
compile of each individual time zone data file (which should help
avoid problems such as the one we had with Nicosia).
Release 1999c - 1999-03-25 09:47:47 -0500
changes by Paul Eggert, most importantly the change for Chile.
Release 1999b - 1999-02-01 17:51:44 -0500
changes by Paul Eggert
code changes (suggested by Mani Varadarajan, mani at be.com) for
correct handling of symbolic links when building using a relative directory
code changes to generate correct messages for failed links
updates to the URLs in Arts.htm
Release 1999a - 1999-01-19 16:20:29 -0500
error message internationalizations and corrections in zic.c and
zdump.c (as suggested by Vladimir Michl, vladimir.michl at upol.cz,
to whom thanks!)
Release code1998h-data1998i - 1998-10-01 09:56:10 -0400
changes for Brazil, Chile, and Germany
support for use of "24:00" in the input files for the time zone compiler
Release code1998g-data1998h - 1998-09-24 10:50:28 -0400
changes by Paul Eggert
correction to a define in the "private.h" file
Release data1998g - 1998-08-11 03:28:35 -0000
[tzdata1998g.tar.gz is missing!]
Lithuanian change provided by mgedmin at pub.osf.it
Move creation of the GMT link with Etc/GMT to "etcetera" (from
"backward") to ensure that the GMT file is created even where folks
don't want the "backward" links (as suggested by Paul Eggert).
Release data1998f - 1998-07-20 13:50:00 -0000
[tzdata1998f.tar.gz is missing!]
Update the "leapseconds" file to include the newly-announced
insertion at the end of 1998.
Release code1998f - 1998-06-01 10:18:31 -0400
addition to localtime.c by Guy Harris
Release 1998e - 1998-05-28 09:56:26 -0400
The Makefile is changed to produce zoneinfo-posix rather than
zoneinfo/posix, and to produce zoneinfo-leaps rather than
zoneinfo/right.
data changes by Paul Eggert
changes from Guy Harris to provide asctime_r and ctime_r
A usno1998 file (substantially identical to usno1997) has been added.
Release 1998d - 1998-05-14 11:58:34 -0400
changes to comments (in particular, elimination of references to CIA maps).
"Arts.htm", "WWW.htm", "asia", and "australasia" are the only places
where changes occur.
Release 1998c - 1998-02-28 12:32:26 -0500
changes by Paul Eggert (save the "French correction," on which I'll
wait for the dust to settle)
symlink changes
changes and additions to Arts.htm
Release 1998b - 1998-01-17 14:31:51 -0500
URL cleanups and additions
Release 1998a - 1998-01-13 12:37:35 -0500
changes by Paul Eggert
Release code1997i-data1997k - 1997-12-29 09:53:41 -0500
changes by Paul Eggert, with minor modifications from Arthur David
Olson to make the files more browser friendly
Release code1997h-data1997j - 1997-12-18 17:47:35 -0500
minor changes to put "TZif" at the start of each timezone information file
a rule has also been added to the Makefile so you can
make zones
to just recompile the zone information files (rather than doing a
full "make install" with its other effects).
Release data1997i - 1997-10-07 08:45:38 -0400
changes to Africa by Paul Eggert
Release code1997g-data1997h - 1997-09-04 16:56:54 -0400
corrections for Uruguay (and other locations)
Arthur David Olson's simple-minded fix allowing mktime to both
correctly handle leap seconds and correctly handle tm_sec values
upon which arithmetic has been performed.
Release code1997f-data1997g - 1997-07-19 13:15:02 -0400
Paul Eggert's updates
a small change to a function prototype;
"Music" has been renamed "Arts.htm", HTMLified, and augmented to
include information on Around the World in Eighty Days.
Release code1997e-data1997f - 1997-05-03 18:52:34 -0400
fixes to zic's error handling
changes inspired by the item circulated on Slovenia
The description of Web resources has been HTMLified for browsing
convenience.
A new piece of tz-related music has been added to the "Music" file.
Release code1997d-data1997e - 1997-03-29 12:48:52 -0500
Paul Eggert's latest suggestions
Release code1997c-data1997d - 1997-03-07 20:37:54 -0500
changes to "zic.c" to correct performance of the "-s" option
a new file "usno1997"
Release data1997c - 1997-03-04 09:58:18 -0500
changes in Israel
Release 1997b - 1997-02-27 18:34:19 -0500
The data file incorporates the 1997 leap second.
The code file incorporates Arthur David Olson's take on the
zic/multiprocessor/directory-creation situation.
Release 1997a - 1997-01-21 09:11:10 -0500
Paul Eggert's Antarctica (and other changes)
Arthur David Olson finessed the "getopt" issue by checking against
both -1 and EOF (regardless of POSIX, SunOS 4.1.1's manual says -1
is returned while SunOS 5.5's manual says EOF is returned).
Release code1996o-data1996n - 1996-12-27 21:42:05 -0500
Paul Eggert's latest changes
Release code1996n - 1996-12-16 09:42:02 -0500
link snapping fix from Bruce Evans (via Garrett Wollman)
Release data1996m - 1996-11-24 02:37:34 -0000
[tzdata1996m.tar.gz is missing!]
Paul Eggert's batch of changes
Release code1996m-data1996l - 1996-11-05 14:00:12 -0500
No functional changes here; the files have simply been changed to
make more use of ISO style dates in comments. The names of the above
files now include the year in full.
Release code96l - 1996-09-08 17:12:20 -0400
tzcode96k was missing a couple of pieces.
Release 96k - 1996-09-08 16:06:22 -0400
the latest round of changes from Paul Eggert
the recent Year 2000 material
Release code96j - 1996-07-30 13:18:53 -0400
Set sp->typecnt as suggested by Timothy Patrick Murphy.
Release code96i - 1996-07-27 20:11:35 -0400
Paul's suggested patch for strftime %V week numbers
Release data96i - 1996-07-01 18:13:04 -0400
"northamerica" and "europe" changes by Paul Eggert
Release code96h - 1996-06-05 08:02:21 -0400
fix for handling transitions specified in Universal Time
Some "public domain" notices have also been added.
Release code96g - 1996-05-16 14:00:26 -0400
fix for the simultaneous-DST-and-zone-change challenge
Release data96h - 1996-05-09 17:40:51 -0400
changes by Paul Eggert
Release code96f-data96g - 1996-05-03 03:09:59 -0000
[tzcode96f.tar.gz + tzdata96g.tar.gz are both missing!]
The changes get us some of the way to fixing the problems noted in Paul
Eggert's letter yesterday (in addition to a few others). The approach
has been to make zic a bit smarter about figuring out what time zone
abbreviations apply just after the time specified in the "UNTIL" part
of a zone line. Putting the smarts in zic means avoiding having
transition times show up in both "Zone" lines and "Rule" lines, which
in turn avoids multiple transition time entries in time zone files.
(This also makes the zic input files such as "europe" a bit shorter and
should ease maintenance.)
Release data96f - 1996-04-19 19:20:03 -0000
[tzdata96f.tar.gz is missing!]
The only changes are to the "northamerica" file; the time zone
abbreviation for Denver is corrected to MST (and MDT), and the
comments for Mexico have been updated.
Release data96e - 1996-03-19 17:37:26 -0500
Proposals by Paul Eggert, in particular the Portugal change that
comes into play at the end of this month.
Release data96d - 1996-03-18 20:49:39 -0500
[not summarized]
Release code96e - 1996-02-29 15:43:27 -0000
[tzcode96e.tar.gz is missing!]
internationalization changes and the fix to the documentation for strftime
Release code96d-data96c - 1996-02-12 11:05:27 -0500
The "code" file simply updates Bob Kridle's electronic address.
The "data" file updates rules for Mexico.
Release data96b - 1996-01-27 15:44:42 -0500
Kiribati change
Release code96c - 1996-01-16 16:58:15 -0500
leap-year streamlining and binary-search changes
fix to newctime.3
Release code96b - 1996-01-10 20:42:39 -0500
fixes and enhancements from Paul Eggert, including code that
emulates the behavior of recent versions of the SunOS "date"
command.
Release 96a - 1996-01-06 09:08:24 -0500
Israel updates
fixes to strftime.c for correct ISO 8601 week number generation,
plus support for two new formats ('G' and 'g') to give ISO 8601 year
numbers (which are not necessarily the same as calendar year numbers)
Release code95i-data95m - 1995-12-21 12:46:47 -0500
The latest revisions from Paul Eggert are included, the usno1995
file has been updated, and a new file ("WWW") covering useful URLs
has been added.
Release code95h-data95l - 1995-12-19 18:10:12 -0500
A simplification of a macro definition, a change to data for Sudan,
and (for last minute shoppers) notes in the "Music" file on the CD
"Old Man Time".
Release code95g-data95k - 1995-10-30 10:32:47 -0500
(slightly reformatted) 8-bit-clean proposed patch
minor patch: US/Eastern -> America/New_York
snapshot of the USNO's latest data ("usno1995")
some other minor cleanups
Release code95f-data95j - 1995-10-28 21:01:34 -0000
[tzcode95f.tar.gz + tzdata95j.tar.gz are both missing!]
European cleanups
support for 64-bit time_t's
optimization in localtime.c
Release code95e - 1995-10-13 13:23:57 -0400
the mktime change to scan from future to past when trying to find time zone
offsets
Release data95i - 1995-09-26 10:43:26 -0400
For Canada/Central, guess that the Sun customer's "one week too
early" was just a approximation, and the true error is one month
too early. This is consistent with the rest of Canada.
Release data95h - 1995-09-21 11:26:48 -0400
latest changes from Paul Eggert
Release code95d - 1995-09-14 11:14:45 -0400
the addition of a "Music" file, which documents four recorded
versions of the tune "Save That Time".
Release data95g - 1995-09-01 17:21:36 -0400
"yearistype" correction
Release data95f - 1995-08-28 20:46:56 -0400
Paul Eggert's change to the australasia file
Release data95e - 1995-07-08 18:02:34 -0400
The only change is a leap second at the end of this year.
Thanks to Bradley White for forwarding news on the leap second.
Release data95d - 1995-07-03 13:26:22 -0400
Paul Eggert's changes
Release data95c - 1995-07-02 19:19:28 -0400
changes to "asia", "backward", "europe", and "southamerica"
(read: northamericacentrics need not apply)
Release code95c - 1995-03-13 14:00:46 -0500
one-line fix for sign extension problems in detzcode
Release 95b - 1995-03-04 11:22:38 -0500
Minor changes in both:
The "code" file contains a workaround for the lack of "unistd.h" in
Microsoft C++ version 7.
The "data" file contains a fixed "Link" for America/Shiprock.
Release 94h - 1994-12-10 12:51:14 -0500
The files:
* incorporate the changes to "zdump" and "date" to make changes to
the "TZ" environment variable permanent;
* incorporate the table changes by Paul Eggert;
* include (and document) support for universal time specifications in
data files - but do not (yet) include use of this feature in the
data files.
Think of this as "TZ Classic" - the software has been set up not to break if
universal time shows up in its input, and data entries have been
left as is so as not to break existing implementations.
Release data94f - 1994-08-20 12:56:09 -0400
(with thanks!) the latest data updates from Paul Eggert
Release data94e - 1994-06-04 13:13:53 -0400
[not summarized]
Release code94g - 1994-05-05 12:14:07 -0400
fix missing "optind.c" and a reference to it in the Makefile
Release code94f - 1994-05-05 13:00:33 -0000
[tzcode94f.tar.gz is missing!]
changes to avoid overflow in difftime, as well as changes to cope
with the 52/53 challenge in strftime
Release code94e - 1994-03-30 23:32:59 -0500
change for the benefit of PCTS
Release 94d - 1994-02-24 15:42:25 -0500
Avoid clashes with POSIX semantics for zones such as GMT+4.
Some other very minor housekeeping is also present.
Release code94c - 1994-02-10 08:52:40 -0500
Fix bug where mkdirs was broken unless you compile with
-fwritable-strings (which is generally losing to do).
Release 94b - 1994-02-07 10:04:33 -0500
work by Paul Eggert who notes:
I found another book of time zone histories by E W Whitman; it's not
as extensive as Shanks but has a few goodies of its own. I used it
to update the tables. I also fixed some more as a result of
correspondence with Adam David and Peter Ilieve, and move some stray
links from 'europe' to 'backward'. I corrected some scanning errors
in usno1989.
As far as the code goes, I fixed zic to allow years in the range
INT_MIN to INT_MAX; this fixed a few boundary conditions around 1900.
And I cleaned up the zic documentation a little bit.
Release data94a - 1994-02-03 08:58:54 -0500
It simply incorporates the recently announced leap second into the
"leapseconds" file.
Release 93g - 1993-11-22 17:28:27 -0500
Paul Eggert has provided a good deal of historic information (based
on Shanks), and there are some code changes to deal with the buglets
that crawled out in dealing with the new information.
Release 93f - 1993-10-15 12:27:46 -0400
Paul Eggert's changes
Release 93e - 1993-09-05 21:21:44 -0400
This has updated data for Israel, England, and Kwajalein. There's
also an update to "zdump" to cope with Kwajalein's 24-hour jump.
Thanks to Paul Eggert and Peter Ilieve for the changes.
Release 93d - 1993-06-17 23:34:17 -0400
new fix and new data on Israel
Release 93c - 1993-06-06 19:31:55 -0400
[not summarized]
Release 93b - 1993-02-02 14:53:58 -0500
updated "leapseconds" file
Release 93 - 1993-01-08 07:01:06 -0500
At kre's suggestion, the package has been split in two - a code piece
(which also includes documentation) that's only of use to folks who
want to recompile things and a data piece useful to anyone who can
run "zic".
The new version has a few changes to the data files, a few
portability changes, and an off-by-one fix (with thanks to
Tom Karzes at deshaw.com for providing a description and a
solution).
Release 92c - 1992-11-21 17:35:36 -0000
[tz92c.tar.Z is missing!]
The fallout from the latest round of DST transitions.
There are changes for Portugal, Saskatchewan, and "Pacific-New";
there's also a change to "zic.c" that makes it portable to more systems.
Release 92 - 1992-04-25 18:17:03 -0000
[tz92.tar.Z is missing!]
By popular demand (well, at any rate, following a request by kre at munnari)
The 1989 update of the time zone package featured:
* POSIXization (including interpretation of POSIX-style TZ environment
variables, provided by Guy Harris),
* ANSIfication (including versions of "mktime" and "difftime"),
* SVIDulation (an "altzone" variable)
* MACHination (the "gtime" function)
* corrections to some time zone data (including corrections to the rules
for Great Britain and New Zealand)
* reference data from the United States Naval Observatory for folks who
want to do additional time zones
* and the 1989 data for Saudi Arabia.
(Since this code will be treated as "part of the implementation" in some
places and as "part of the application" in others, there's no good way to
name functions, such as timegm, that are not part of the proposed ANSI C
standard; such functions have kept their old, underscore-free names in this
update.)
And the "dysize" function has disappeared; it was present to allow
compilation of the "date" command on old BSD systems, and a version of "date"
is now provided in the package. The "date" command is not created when you
"make all" since it may lack options provided by the version distributed with
your operating system, or may not interact with the system in the same way
the native version does.
Since POSIX frowns on correct leap second handling, the default behavior of
the "zic" command (in the absence of a "-L" option) has been changed to omit
leap second information from its output files.
-----
Notes
This file contains copies of the part of each release announcement
that talks about the changes in that release. The text has been
adapted and reformatted for the purposes of this file.
Traditionally a release R consists of a pair of tarball files,
tzcodeR.tar.gz and tzdataR.tar.gz. However, some releases (e.g.,
code2010a, data2012c) consist of just one or the other tarball, and a
few (e.g., code2012c-data2012d) have tarballs with mixed version
numbers. Recent releases also come in an experimental format
consisting of a single tarball tzdb-R.tar.lz with extra data.
Release timestamps are taken from the release's commit (for newer,
Git-based releases), from the newest file in the tarball (for older
releases, where this info is available) or from the email announcing
the release (if all else fails; these are marked with a time zone
abbreviation of -0000 and an "is missing!" comment).
Earlier versions of the code and data were not announced on the tz
list and are not summarized here.
This file is in the public domain.
Local Variables:
coding: utf-8
End:
Index: stable/12/contrib/tzdata/asia
===================================================================
--- stable/12/contrib/tzdata/asia (revision 352352)
+++ stable/12/contrib/tzdata/asia (revision 352353)
@@ -1,3650 +1,3659 @@
# tzdb data for Asia and environs
# This file is in the public domain, so clarified as of
# 2009-05-17 by Arthur David Olson.
# This file is by no means authoritative; if you think you know better,
# go ahead and edit the file (and please send any changes to
# tz@iana.org for general use in the future). For more, please see
# the file CONTRIBUTING in the tz distribution.
-# From Paul Eggert (2018-06-19):
+# From Paul Eggert (2019-07-11):
#
# Unless otherwise specified, the source for data through 1990 is:
# Thomas G. Shanks and Rique Pottenger, The International Atlas (6th edition),
# San Diego: ACS Publications, Inc. (2003).
# Unfortunately this book contains many errors and cites no sources.
#
# Many years ago Gwillim Law wrote that a good source
# for time zone data was the International Air Transport
# Association's Standard Schedules Information Manual (IATA SSIM),
# published semiannually. Law sent in several helpful summaries
# of the IATA's data after 1990. Except where otherwise noted,
# IATA SSIM is the source for entries after 1990.
#
# Another source occasionally used is Edward W. Whitman, World Time Differences,
# Whitman Publishing Co, 2 Niagara Av, Ealing, London (undated), which
# I found in the UCLA library.
#
# For data circa 1899, a common source is:
# Milne J. Civil time. Geogr J. 1899 Feb;13(2):173-94.
# https://www.jstor.org/stable/1774359
#
# For Russian data circa 1919, a source is:
# Byalokoz EL. New Counting of Time in Russia since July 1, 1919.
# (See the 'europe' file for a fuller citation.)
#
# A reliable and entertaining source about time zones is
# Derek Howse, Greenwich time and longitude, Philip Wilson Publishers (1997).
#
# The following alphabetic abbreviations appear in these tables
# (corrections are welcome):
# std dst
# LMT Local Mean Time
# 2:00 EET EEST Eastern European Time
# 2:00 IST IDT Israel
# 5:30 IST India
# 7:00 WIB west Indonesia (Waktu Indonesia Barat)
# 8:00 WITA central Indonesia (Waktu Indonesia Tengah)
# 8:00 CST China
-# 8:00 PST PDT* Philippine Standard Time
+# 8:00 HKT HKST Hong Kong (HKWT* for Winter Time in late 1941)
+# 8:00 PST PDT* Philippines
# 8:30 KST KDT Korea when at +0830
# 9:00 WIT east Indonesia (Waktu Indonesia Timur)
# 9:00 JST JDT Japan
# 9:00 KST KDT Korea when at +09
-# 9:30 ACST Australian Central Standard Time
-# *I invented the abbreviation PDT; see "Philippines" below.
+# *I invented the abbreviations HKWT and PDT; see below.
# Otherwise, these tables typically use numeric abbreviations like +03
# and +0330 for integer hour and minute UT offsets. Although earlier
# editions invented alphabetic time zone abbreviations for every
# offset, this did not reflect common practice.
#
# See the 'europe' file for Russia and Turkey in Asia.
# From Guy Harris:
# Incorporates data for Singapore from Robert Elz' asia 1.1, as well as
# additional information from Tom Yap, Sun Microsystems Intercontinental
# Technical Support (including a page from the Official Airline Guide -
# Worldwide Edition).
###############################################################################
# These rules are stolen from the 'europe' file.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule EUAsia 1981 max - Mar lastSun 1:00u 1:00 S
Rule EUAsia 1979 1995 - Sep lastSun 1:00u 0 -
Rule EUAsia 1996 max - Oct lastSun 1:00u 0 -
Rule E-EurAsia 1981 max - Mar lastSun 0:00 1:00 -
Rule E-EurAsia 1979 1995 - Sep lastSun 0:00 0 -
Rule E-EurAsia 1996 max - Oct lastSun 0:00 0 -
Rule RussiaAsia 1981 1984 - Apr 1 0:00 1:00 -
Rule RussiaAsia 1981 1983 - Oct 1 0:00 0 -
Rule RussiaAsia 1984 1995 - Sep lastSun 2:00s 0 -
Rule RussiaAsia 1985 2010 - Mar lastSun 2:00s 1:00 -
Rule RussiaAsia 1996 2010 - Oct lastSun 2:00s 0 -
# Afghanistan
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Kabul 4:36:48 - LMT 1890
4:00 - +04 1945
4:30 - +0430
# Armenia
# From Paul Eggert (2006-03-22):
# Shanks & Pottenger have Yerevan switching to 3:00 (with Russian DST)
# in spring 1991, then to 4:00 with no DST in fall 1995, then
# readopting Russian DST in 1997. Go with Shanks & Pottenger, even
# when they disagree with others. Edgar Der-Danieliantz
# reported (1996-05-04) that Yerevan probably wouldn't use DST
# in 1996, though it did use DST in 1995. IATA SSIM (1991/1998) reports that
# Armenia switched from 3:00 to 4:00 in 1998 and observed DST after 1991,
# but started switching at 3:00s in 1998.
# From Arthur David Olson (2011-06-15):
# While Russia abandoned DST in 2011, Armenia may choose to
# follow Russia's "old" rules.
# From Alexander Krivenyshev (2012-02-10):
# According to News Armenia, on Feb 9, 2012,
# http://newsarmenia.ru/society/20120209/42609695.html
#
# The Armenia National Assembly adopted final reading of Amendments to the
# Law "On procedure of calculation time on the territory of the Republic of
# Armenia" according to which Armenia [is] abolishing Daylight Saving Time.
# or
# (brief)
# http://www.worldtimezone.com/dst_news/dst_news_armenia03.html
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Armenia 2011 only - Mar lastSun 2:00s 1:00 -
Rule Armenia 2011 only - Oct lastSun 2:00s 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Yerevan 2:58:00 - LMT 1924 May 2
3:00 - +03 1957 Mar
4:00 RussiaAsia +04/+05 1991 Mar 31 2:00s
3:00 RussiaAsia +03/+04 1995 Sep 24 2:00s
4:00 - +04 1997
4:00 RussiaAsia +04/+05 2011
4:00 Armenia +04/+05
# Azerbaijan
# From Rustam Aliyev of the Azerbaijan Internet Forum (2005-10-23):
# According to the resolution of Cabinet of Ministers, 1997
# From Paul Eggert (2015-09-17): It was Resolution No. 21 (1997-03-17).
# http://code.az/files/daylight_res.pdf
# From Steffen Thorsen (2016-03-17):
# ... the Azerbaijani Cabinet of Ministers has cancelled switching to
# daylight saving time....
# https://www.azernews.az/azerbaijan/94137.html
# http://vestnikkavkaza.net/news/Azerbaijani-Cabinet-of-Ministers-cancels-daylight-saving-time.html
# http://en.apa.az/xeber_azerbaijan_abolishes_daylight_savings_ti_240862.html
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Azer 1997 2015 - Mar lastSun 4:00 1:00 -
Rule Azer 1997 2015 - Oct lastSun 5:00 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Baku 3:19:24 - LMT 1924 May 2
3:00 - +03 1957 Mar
4:00 RussiaAsia +04/+05 1991 Mar 31 2:00s
3:00 RussiaAsia +03/+04 1992 Sep lastSun 2:00s
4:00 - +04 1996
4:00 EUAsia +04/+05 1997
4:00 Azer +04/+05
# Bahrain
# See Asia/Qatar.
# Bangladesh
# From Alexander Krivenyshev (2009-05-13):
# According to newspaper Asian Tribune (May 6, 2009) Bangladesh may introduce
# Daylight Saving Time from June 16 to Sept 30
#
# Bangladesh to introduce daylight saving time likely from June 16
# http://www.asiantribune.com/?q=node/17288
# http://www.worldtimezone.com/dst_news/dst_news_bangladesh02.html
#
# "... Bangladesh government has decided to switch daylight saving time from
# June
# 16 till September 30 in a bid to ensure maximum use of daylight to cope with
# crippling power crisis. "
#
# The switch will remain in effect from June 16 to Sept 30 (2009) but if
# implemented the next year, it will come in force from April 1, 2010
# From Steffen Thorsen (2009-06-02):
# They have finally decided now, but changed the start date to midnight between
# the 19th and 20th, and they have not set the end date yet.
#
# Some sources:
# https://in.reuters.com/article/southAsiaNews/idINIndia-40017620090601
# http://bdnews24.com/details.php?id=85889&cid=2
#
# Our wrap-up:
# https://www.timeanddate.com/news/time/bangladesh-daylight-saving-2009.html
# From A. N. M. Kamrus Saadat (2009-06-15):
# Finally we've got the official mail regarding DST start time where DST start
# time is mentioned as Jun 19 2009, 23:00 from BTRC (Bangladesh
# Telecommunication Regulatory Commission).
#
# No DST end date has been announced yet.
# From Alexander Krivenyshev (2009-09-25):
# Bangladesh won't go back to Standard Time from October 1, 2009,
# instead it will continue DST measure till the cabinet makes a fresh decision.
#
# Following report by same newspaper-"The Daily Star Friday":
# "DST change awaits cabinet decision-Clock won't go back by 1-hr from Oct 1"
# http://www.thedailystar.net/newDesign/news-details.php?nid=107021
# http://www.worldtimezone.com/dst_news/dst_news_bangladesh04.html
# From Steffen Thorsen (2009-10-13):
# IANS (Indo-Asian News Service) now reports:
# Bangladesh has decided that the clock advanced by an hour to make
# maximum use of daylight hours as an energy saving measure would
# "continue for an indefinite period."
#
# One of many places where it is published:
# http://www.thaindian.com/newsportal/business/bangladesh-to-continue-indefinitely-with-advanced-time_100259987.html
# From Alexander Krivenyshev (2009-12-24):
# According to Bangladesh newspaper "The Daily Star,"
# Bangladesh will change its clock back to Standard Time on Dec 31, 2009.
#
# Clock goes back 1-hr on Dec 31 night.
# http://www.thedailystar.net/newDesign/news-details.php?nid=119228
# http://www.worldtimezone.com/dst_news/dst_news_bangladesh05.html
#
# "...The government yesterday decided to put the clock back by one hour
# on December 31 midnight and the new time will continue until March 31,
# 2010 midnight. The decision came at a cabinet meeting at the Prime
# Minister's Office last night..."
# From Alexander Krivenyshev (2010-03-22):
# According to Bangladesh newspaper "The Daily Star,"
# Cabinet cancels Daylight Saving Time
# http://www.thedailystar.net/newDesign/latest_news.php?nid=22817
# http://www.worldtimezone.com/dst_news/dst_news_bangladesh06.html
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Dhaka 2009 only - Jun 19 23:00 1:00 -
Rule Dhaka 2009 only - Dec 31 24:00 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Dhaka 6:01:40 - LMT 1890
5:53:20 - HMT 1941 Oct # Howrah Mean Time?
6:30 - +0630 1942 May 15
5:30 - +0530 1942 Sep
6:30 - +0630 1951 Sep 30
6:00 - +06 2009
6:00 Dhaka +06/+07
# Bhutan
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Thimphu 5:58:36 - LMT 1947 Aug 15 # or Thimbu
5:30 - +0530 1987 Oct
6:00 - +06
# British Indian Ocean Territory
# Whitman and the 1995 CIA time zone map say 5:00, but the
# 1997 and later maps say 6:00. Assume the switch occurred in 1996.
# We have no information as to when standard time was introduced;
# assume it occurred in 1907, the same year as Mauritius (which
# then contained the Chagos Archipelago).
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Indian/Chagos 4:49:40 - LMT 1907
5:00 - +05 1996
6:00 - +06
# Brunei
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Brunei 7:39:40 - LMT 1926 Mar # Bandar Seri Begawan
7:30 - +0730 1933
8:00 - +08
# Burma / Myanmar
# Milne says 6:24:40 was the meridian of the time ball observatory at Rangoon.
# From Paul Eggert (2017-04-20):
# Page 27 of Reed & Low (cited for Asia/Kolkata) says "Rangoon local time is
# used upon the railways and telegraphs of Burma, and is 6h. 24m. 47s. ahead
# of Greenwich." This refers to the period before Burma's transition to +0630,
# a transition for which Shanks is the only source.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Yangon 6:24:47 - LMT 1880 # or Rangoon
6:24:47 - RMT 1920 # Rangoon local time
6:30 - +0630 1942 May
9:00 - +09 1945 May 3
6:30 - +0630
# Cambodia
# See Asia/Bangkok.
# China
# From Paul Eggert (2018-10-02):
# The following comes from Table 1 of:
# Li Yu. Research on the daylight saving movement in 1940s Shanghai.
# Nanjing Journal of Social Sciences. 2014;(2):144-50.
# http://oversea.cnki.net/kns55/detail.aspx?dbname=CJFD2014&filename=NJSH201402020
# The table lists dates only; I am guessing 00:00 and 24:00 transition times.
# Also, the table lists the planned end of DST in 1949, but the corresponding
# zone line cuts this off on May 28, when the Communists took power.
#
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Shang 1940 only - Jun 1 0:00 1:00 D
Rule Shang 1940 only - Oct 12 24:00 0 S
Rule Shang 1941 only - Mar 15 0:00 1:00 D
Rule Shang 1941 only - Nov 1 24:00 0 S
Rule Shang 1942 only - Jan 31 0:00 1:00 D
Rule Shang 1945 only - Sep 1 24:00 0 S
Rule Shang 1946 only - May 15 0:00 1:00 D
Rule Shang 1946 only - Sep 30 24:00 0 S
Rule Shang 1947 only - Apr 15 0:00 1:00 D
Rule Shang 1947 only - Oct 31 24:00 0 S
Rule Shang 1948 1949 - May 1 0:00 1:00 D
Rule Shang 1948 1949 - Sep 30 24:00 0 S #plan
# From Guy Harris:
# People's Republic of China. Yes, they really have only one time zone.
# From Bob Devine (1988-01-28):
# No they don't. See TIME mag, 1986-02-17 p.52. Even though
# China is across 4 physical time zones, before Feb 1, 1986 only the
# Peking (Beijing) time zone was recognized. Since that date, China
# has two of 'em - Peking's and Ürümqi (named after the capital of
# the Xinjiang Uyghur Autonomous Region). I don't know about DST for it.
#
# . . .I just deleted the DST table and this editor makes it too
# painful to suck in another copy. So, here is what I have for
# DST start/end dates for Peking's time zone (info from AP):
#
# 1986 May 4 - Sept 14
# 1987 mid-April - ??
# From U. S. Naval Observatory (1989-01-19):
# CHINA 8 H AHEAD OF UTC ALL OF CHINA, INCL TAIWAN
# CHINA 9 H AHEAD OF UTC APR 17 - SEP 10
# From Paul Eggert (2008-02-11):
# Jim Mann, "A clumsy embrace for another western custom: China on daylight
# time - sort of", Los Angeles Times, 1986-05-05 ... [says] that China began
# observing daylight saving time in 1986.
# From P Chan (2018-05-07):
# The start and end time of DST in China [from 1986 on] should be 2:00
# (i.e. 2:00 to 3:00 at the start and 2:00 to 1:00 at the end)....
# Government notices about summer time:
#
# 1986-04-12 http://www.zj.gov.cn/attach/zfgb/198608.pdf p.21-22
# (To establish summer time from 1986. On 4 May, set the clocks ahead one hour
# at 2 am. On 14 September, set the clocks backward one hour at 2 am.)
#
# 1987-02-15 http://www.gov.cn/gongbao/shuju/1987/gwyb198703.pdf p.114
# (Summer time in 1987 to start from 12 April until 13 September)
#
# 1987-09-09 http://www.gov.cn/gongbao/shuju/1987/gwyb198721.pdf p.709
# (From 1988, summer time to start from 2 am of the first Sunday of mid-April
# until 2 am of the first Sunday of mid-September)
#
# 1992-03-03 http://www.gov.cn/gongbao/shuju/1992/gwyb199205.pdf p.152
# (To suspend summer time from 1992)
#
# The first page of People's Daily on 12 April 1988 stating that summer time
# to begin on 17 April.
# http://data.people.com.cn/pic/101p/1988/04/1988041201.jpg
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule PRC 1986 only - May 4 2:00 1:00 D
Rule PRC 1986 1991 - Sep Sun>=11 2:00 0 S
Rule PRC 1987 1991 - Apr Sun>=11 2:00 1:00 D
# From Anthony Fok (2001-12-20):
# BTW, I did some research on-line and found some info regarding these five
# historic timezones from some Taiwan websites. And yes, there are official
# Chinese names for these locales (before 1949).
#
# From Jesper Nørgaard Welen (2006-07-14):
# I have investigated the timezones around 1970 on the
# https://www.astro.com/atlas site [with provinces and county
# boundaries summarized below].... A few other exceptions were two
# counties on the Sichuan side of the Xizang-Sichuan border,
# counties Dege and Baiyu which lies on the Sichuan side and are
# therefore supposed to be GMT+7, Xizang region being GMT+6, but Dege
# county is GMT+8 according to astro.com while Baiyu county is GMT+6
# (could be true), for the moment I am assuming that those two
# counties are mistakes in the astro.com data.
# From Paul Eggert (2017-01-05):
# Alois Treindl kindly sent me translations of the following two sources:
#
# (1)
# Guo Qing-sheng (National Time-Service Center, CAS, Xi'an 710600, China)
# Beijing Time at the Beginning of the PRC
# China Historical Materials of Science and Technology
# (Zhongguo ke ji shi liao, 中国科技史料). 2003;24(1):5-9.
# http://oversea.cnki.net/kcms/detail/detail.aspx?filename=ZGKS200301000&dbname=CJFD2003
# It gives evidence that at the beginning of the PRC, Beijing time was
# officially apparent solar time! However, Guo also says that the
# evidence is dubious, as the relevant institute of astronomy had not
# been taken over by the PRC yet. It's plausible that apparent solar
# time was announced but never implemented, and that people continued
# to use UT+8. As the Shanghai radio station (and I presume the
# observatory) was still under control of French missionaries, it
# could well have ignored any such mandate.
#
# (2)
# Guo Qing-sheng (Shaanxi Astronomical Observatory, CAS, Xi'an 710600, China)
# A Study on the Standard Time Changes for the Past 100 Years in China
# [undated and unknown publication location]
# It says several things:
# * The Qing dynasty used local apparent solar time throughout China.
# * The Republic of China instituted Beijing mean solar time effective
# the official calendar book of 1914.
# * The French Concession in Shanghai set up signal stations in
# French docks in the 1890s, controlled by Xujiahui (Zikawei)
# Observatory and set to local mean time.
# * "From the end of the 19th century" it changed to UT+8.
# * Chinese Customs (by then reduced to a tool of foreign powers)
# eventually standardized on this time for all ports, and it
# became used by railways as well.
# * In 1918 the Central Observatory proposed dividing China into
# five time zones (see below for details). This caught on
# at first only in coastal areas observing UT+8.
# * During WWII all of China was in theory was at UT+7. In practice
# this was ignored in the west, and I presume was ignored in
# Japanese-occupied territory.
# * Japanese-occupied Manchuria was at UT+9, i.e., Japan time.
# * The five-zone plan was resurrected after WWII and officially put into
# place (with some modifications) in March 1948. It's not clear
# how well it was observed in areas under Nationalist control.
# * The People's Liberation Army used UT+8 during the civil war.
#
# An AP article "Shanghai Internat'l Area Little Changed" in the
# Lewiston (ME) Daily Sun (1939-05-29), p 17, said "Even the time is
# different - the occupied districts going by Tokyo time, an hour
# ahead of that prevailing in the rest of Shanghai." Guess that the
# Xujiahui Observatory was under French control and stuck with UT +08.
#
# In earlier versions of this file, China had many separate Zone entries, but
# this was based on what were apparently incorrect data in Shanks & Pottenger.
# This has now been simplified to the two entries Asia/Shanghai and
# Asia/Urumqi, with the others being links for backward compatibility.
# Proposed in 1918 and theoretically in effect until 1949 (although in practice
# mainly observed in coastal areas), the five zones were:
#
# Changbai Time ("Long-white Time", Long-white = Heilongjiang area) UT +08:30
# Now part of Asia/Shanghai; its pre-1970 times are not recorded here.
# Heilongjiang (except Mohe county), Jilin
#
# Zhongyuan Time ("Central plain Time") UT +08
# Now part of Asia/Shanghai.
# most of China
# Milne gives 8:05:43.2 for Xujiahui Observatory time; round to nearest.
# Guo says Shanghai switched to UT +08 "from the end of the 19th century".
#
# Long-shu Time (probably as Long and Shu were two names of the area) UT +07
# Now part of Asia/Shanghai; its pre-1970 times are not recorded here.
# Guangxi, Guizhou, Hainan, Ningxia, Sichuan, Shaanxi, and Yunnan;
# most of Gansu; west Inner Mongolia; east Qinghai; and the Guangdong
# counties Deqing, Enping, Kaiping, Luoding, Taishan, Xinxing,
# Yangchun, Yangjiang, Yu'nan, and Yunfu.
#
# Xin-zang Time ("Xinjiang-Tibet Time") UT +06
# This region is now part of either Asia/Urumqi or Asia/Shanghai with
# current boundaries uncertain; times before 1970 for areas that
# disagree with Ürümqi or Shanghai are not recorded here.
# The Gansu counties Aksay, Anxi, Dunhuang, Subei; west Qinghai;
# the Guangdong counties Xuwen, Haikang, Suixi, Lianjiang,
# Zhanjiang, Wuchuan, Huazhou, Gaozhou, Maoming, Dianbai, and Xinyi;
# east Tibet, including Lhasa, Chamdo, Shigaise, Jimsar, Shawan and Hutubi;
# east Xinjiang, including Ürümqi, Turpan, Karamay, Korla, Minfeng, Jinghe,
# Wusu, Qiemo, Xinyan, Wulanwusu, Jinghe, Yumin, Tacheng, Tuoli, Emin,
# Shihezi, Changji, Yanqi, Heshuo, Tuokexun, Tulufan, Shanshan, Hami,
# Fukang, Kuitun, Kumukuli, Miquan, Qitai, and Turfan.
#
# Kunlun Time UT +05:30
# This region is now in the same status as Xin-zang Time (see above).
# West Tibet, including Pulan, Aheqi, Shufu, Shule;
# West Xinjiang, including Aksu, Atushi, Yining, Hetian, Cele, Luopu, Nileke,
# Zhaosu, Tekesi, Gongliu, Chabuchaer, Huocheng, Bole, Pishan, Suiding,
# and Yarkand.
# From Luther Ma (2009-10-17):
# Almost all (>99.9%) ethnic Chinese (properly ethnic Han) living in
# Xinjiang use Chinese Standard Time. Some are aware of Xinjiang time,
# but have no need of it. All planes, trains, and schools function on
# what is called "Beijing time." When Han make an appointment in Chinese
# they implicitly use Beijing time.
#
# On the other hand, ethnic Uyghurs, who make up about half the
# population of Xinjiang, typically use "Xinjiang time" which is two
# hours behind Beijing time, or UT +06. The government of the Xinjiang
# Uyghur Autonomous Region, (XAUR, or just Xinjiang for short) as well as
# local governments such as the Ürümqi city government use both times in
# publications, referring to what is popularly called Xinjiang time as
# "Ürümqi time." When Uyghurs make an appointment in the Uyghur language
# they almost invariably use Xinjiang time.
#
# (Their ethnic Han compatriots would typically have no clue of its
# widespread use, however, because so extremely few of them are fluent in
# Uyghur, comparable to the number of Anglo-Americans fluent in Navajo.)
#
# (...As with the rest of China there was a brief interval ending in 1990
# or 1991 when summer time was in use. The confusion was severe, with
# the province not having dual times but four times in use at the same
# time. Some areas remained on standard Xinjiang time or Beijing time and
# others moving their clocks ahead.)
# From Luther Ma (2009-11-19):
# With the risk of being redundant to previous answers these are the most common
# English "transliterations" (w/o using non-English symbols):
#
# 1. Wulumuqi...
# 2. Kashi...
# 3. Urumqi...
# 4. Kashgar...
# ...
# 5. It seems that Uyghurs in Ürümqi has been using Xinjiang since at least the
# 1960's. I know of one Han, now over 50, who grew up in the surrounding
# countryside and used Xinjiang time as a child.
#
# 6. Likewise for Kashgar and the rest of south Xinjiang I don't know of any
# start date for Xinjiang time.
#
# Without having access to local historical records, nor the ability to legally
# publish them, I would go with October 1, 1949, when Xinjiang became the Uyghur
# Autonomous Region under the PRC. (Before that Uyghurs, of course, would also
# not be using Beijing time, but some local time.)
# From David Cochrane (2014-03-26):
# Just a confirmation that Ürümqi time was implemented in Ürümqi on 1 Feb 1986:
# https://content.time.com/time/magazine/article/0,9171,960684,00.html
# From Luther Ma (2014-04-22):
# I have interviewed numerous people of various nationalities and from
# different localities in Xinjiang and can confirm the information in Guo's
# report regarding Xinjiang, as well as the Time article reference by David
# Cochrane. Whether officially recognized or not (and both are officially
# recognized), two separate times have been in use in Xinjiang since at least
# the Cultural Revolution: Xinjiang Time (XJT), aka Ürümqi Time or local time;
# and Beijing Time. There is no confusion in Xinjiang as to which name refers
# to which time. Both are widely used in the province, although in some
# population groups might be use one to the exclusion of the other. The only
# problem is that computers and smart phones list Ürümqi (or Kashgar) as
# having the same time as Beijing.
# From Paul Eggert (2014-06-30):
# In the early days of the PRC, Tibet was given its own time zone (UT +06)
# but this was withdrawn in 1959 and never reinstated; see Tubten Khétsun,
# Memories of life in Lhasa under Chinese Rule, Columbia U Press, ISBN
# 978-0231142861 (2008), translator's introduction by Matthew Akester, p x.
# As this is before our 1970 cutoff, Tibet doesn't need a separate zone.
#
# Xinjiang Time is well-documented as being officially recognized. E.g., see
# "The Working-Calendar for The Xinjiang Uygur Autonomous Region Government"
# <http://www.sinkiang.gov.cn/service/ourworking/> (2014-04-22).
# Unfortunately, we have no good records of time in Xinjiang before 1986.
# During the 20th century parts of Xinjiang were ruled by the Qing dynasty,
# the Republic of China, various warlords, the First and Second East Turkestan
# Republics, the Soviet Union, the Kuomintang, and the People's Republic of
# China, and tracking down all these organizations' timekeeping rules would be
# quite a trick. Approximate this lost history by a transition from LMT to
# UT +06 at the start of 1928, the year of accession of the warlord Jin Shuren,
# which happens to be the date given by Shanks & Pottenger (no doubt as a
# guess) as the transition from LMT. Ignore the usage of +08 before
# 1986-02-01 under the theory that the transition date to +08 is unknown and
# that the sort of users who prefer Asia/Urumqi now typically ignored the
# +08 mandate back then.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
# Beijing time, used throughout China; represented by Shanghai.
Zone Asia/Shanghai 8:05:43 - LMT 1901
8:00 Shang C%sT 1949 May 28
8:00 PRC C%sT
# Xinjiang time, used by many in western China; represented by Ürümqi / Ürümchi
# / Wulumuqi. (Please use Asia/Shanghai if you prefer Beijing time.)
Zone Asia/Urumqi 5:50:20 - LMT 1928
6:00 - +06
# Hong Kong (Xianggang)
# Milne gives 7:36:41.7; round this.
# From Lee Yiu Chung (2009-10-24):
# I found there are some mistakes for the...DST rule for Hong
# Kong. [According] to the DST record from Hong Kong Observatory (actually,
# it is not [an] observatory, but the official meteorological agency of HK,
# and also serves as the official timing agency), there are some missing
# and incorrect rules. Although the exact switch over time is missing, I
# think 3:30 is correct. The official DST record for Hong Kong can be
# obtained from
# http://www.hko.gov.hk/gts/time/Summertime.htm
# From Phake Nick (2018-10-27):
# According to Singaporean newspaper
# http://eresources.nlb.gov.sg/newspapers/Digitised/Article/singfreepresswk19041102-1.2.37
# the day that Hong Kong start using GMT+8 should be Oct 30, 1904.
#
# From Paul Eggert (2018-11-17):
# Hong Kong had a time ball near the Marine Police Station, Tsim Sha Tsui.
# "The ball was raised manually each day and dropped at exactly 1pm
# (except on Sundays and Government holidays)."
# Dyson AD. From Time Ball to Atomic Clock. Hong Kong Government. 1983.
# <https://www.hko.gov.hk/publica/gen_pub/timeball_atomic_clock.pdf>
# "From 1904 October 30 the time-ball at Hong Kong has been dropped by order
# of the Governor of the Colony at 17h 0m 0s G.M.T., which is 23m 18s.14 in
# advance of 1h 0m 0s of Hong Kong mean time."
# Hollis HP. Universal Time, Longitudes, and Geodesy. Mon Not R Astron Soc.
# 1905-02-10;65(4):405-6. https://doi.org/10.1093/mnras/65.4.382
#
# From Joseph Myers (2018-11-18):
# An astronomer before 1925 referring to GMT would have been using the old
# astronomical convention where the day started at noon, not midnight.
#
# From Steve Allen (2018-11-17):
# Meteorological Observations made at the Hongkong Observatory in the year 1904
# page 4 <https://books.google.com/books?id=kgw5AQAAMAAJ&pg=RA4-PA4>
# ... the log of drop times in Table II shows that on Sunday 1904-10-30 the
# ball was dropped. So that looks like a special case drop for the sake
# of broadcasting the new local time.
#
# From Phake Nick (2018-11-18):
# According to The Hong Kong Weekly Press, 1904-10-29, p.324, the
# governor of Hong Kong at the time stated that "We are further desired to
# make it known that the change will be effected by firing the gun and by the
# dropping of the Ball at 23min. 18sec. before one."
# From Paul Eggert (2018-11-18):
# See <https://mmis.hkpl.gov.hk> for this; unfortunately Flash is required.
# From Phake Nick (2018-10-26):
# I went to check microfilm records stored at Hong Kong Public Library....
# on September 30 1941, according to Ta Kung Pao (Hong Kong edition), it was
# stated that fallback would occur on the next day (the 1st)'s "03:00 am (Hong
# Kong Time 04:00 am)" and the clock will fall back for a half hour. (03:00
# probably refer to the time commonly used in mainland China at the time given
# the paper's background) ... the sunrise/sunset time given by South China
# Morning Post for October 1st was indeed moved by half an hour compares to
# before. After that, in December, the battle to capture Hong Kong started and
# the library doesn't seems to have any record stored about press during that
# period of time. Some media resumed publication soon after that within the
# same month, but there were not much information about time there. Later they
# started including a radio program guide when they restored radio service,
# explicitly mentioning it use Tokyo standard time, and later added a note
# saying it's half an hour ahead of the old Hong Kong standard time, and it
# also seems to indicate that Hong Kong was not using GMT+8 when it was
# captured by Japan.
#
# Image of related sections on newspaper:
# * 1941-09-30, Ta Kung Pao (Hong Kong), "Winter Time start tomorrow".
# https://i.imgur.com/6waY51Z.jpg (Chinese)
# * 1941-09-29, South China Morning Post, Information on sunrise/sunset
# time and other things for September 30 and October 1.
# https://i.imgur.com/kCiUR78.jpg
# * 1942-02-05. The Hong Kong News, Radio Program Guide.
# https://i.imgur.com/eVvDMzS.jpg
# * 1941-06-14. Hong Kong Daily Press, Daylight Saving from 3am Tomorrow.
# https://i.imgur.com/05KkvtC.png
# * 1941-09-30, Hong Kong Daily Press, Winter Time Warning.
# https://i.imgur.com/dge4kFJ.png
+# From Paul Eggert (2019-07-11):
+# "Hong Kong winter time" is considered to be daylight saving.
+# "Hong Kong had adopted daylight saving on June 15 as a wartime measure,
+# clocks moving forward one hour until October 1, when they would be put back
+# by just half an hour for 'Hong Kong Winter time', so that daylight saving
+# operated year round." -- Low Z. The longest day: when wartime Hong Kong
+# introduced daylight saving. South China Morning Post. 2019-06-28.
+# https://www.scmp.com/magazines/post-magazine/short-reads/article/3016281/longest-day-when-wartime-hong-kong-introduced
+
# From P Chan (2018-12-31):
# * According to the Hong Kong Daylight-Saving Regulations, 1941, the
# 1941 spring-forward transition was at 03:00.
# http://sunzi.lib.hku.hk/hkgro/view/g1941/304271.pdf
# http://sunzi.lib.hku.hk/hkgro/view/g1941/305516.pdf
# * According to some articles from South China Morning Post, +08 was
# resumed on 1945-11-18 at 02:00.
# https://i.imgur.com/M2IsZ3c.png
# https://i.imgur.com/iOPqrVo.png
# https://i.imgur.com/fffcGDs.png
# * Some newspapers ... said the 1946 spring-forward transition was on
# 04-21 at 00:00. The Kung Sheung Evening News 1946-04-20 (Chinese)
# https://i.imgur.com/ZSzent0.png
# https://mmis.hkpl.gov.hk///c/portal/cover?c=QF757YsWv5%2FH7zGe%2FKF%2BFLYsuqGhRBfe p.4
# The Kung Sheung Daily News 1946-04-21 (Chinese)
# https://i.imgur.com/7ecmRlcm.png
# https://mmis.hkpl.gov.hk///c/portal/cover?c=QF757YsWv5%2BQBGt1%2BwUj5qG2GqtwR3Wh p.4
# * According to the Summer Time Ordinance (1946), the fallback
# transitions between 1946 and 1952 were at 03:30 Standard Time (+08)
# http://oelawhk.lib.hku.hk/archive/files/bb74b06a74d5294620a15de560ab33c6.pdf
# * Some other laws and regulations related to DST from 1953 to 1979
# Summer Time Ordinance 1953
# https://i.imgur.com/IOlJMav.jpg
# Summer Time (Amendment) Ordinance 1965
# https://i.imgur.com/8rofeLa.jpg
# Interpretation and General Clauses Ordinance (1966)
# https://i.imgur.com/joy3msj.jpg
# Emergency (Summer Time) Regulation 1973 <https://i.imgur.com/OpRWrKz.jpg>
# Interpretation and General Clauses (Amendment) Ordinance 1977
# https://i.imgur.com/RaNqnc4.jpg
# Resolution of the Legislative Council passed on 9 May 1979
# https://www.legco.gov.hk/yr78-79/english/lc_sitg/hansard/h790509.pdf#page=39
# From Paul Eggert (2019-05-31):
# Here are the dates given at
# https://www.hko.gov.hk/gts/time/Summertime.htm
# as of 2014-06-19:
# Year Period
# 1941 15 Jun to 30 Sep
# 1942 Whole year
# 1943 Whole year
# 1944 Whole year
# 1945 Whole year
# 1946 20 Apr to 1 Dec
# 1947 13 Apr to 30 Nov
# 1948 2 May to 31 Oct
# 1949 3 Apr to 30 Oct
# 1950 2 Apr to 29 Oct
# 1951 1 Apr to 28 Oct
# 1952 6 Apr to 2 Nov
# 1953 5 Apr to 1 Nov
# 1954 21 Mar to 31 Oct
# 1955 20 Mar to 6 Nov
# 1956 18 Mar to 4 Nov
# 1957 24 Mar to 3 Nov
# 1958 23 Mar to 2 Nov
# 1959 22 Mar to 1 Nov
# 1960 20 Mar to 6 Nov
# 1961 19 Mar to 5 Nov
# 1962 18 Mar to 4 Nov
# 1963 24 Mar to 3 Nov
# 1964 22 Mar to 1 Nov
# 1965 18 Apr to 17 Oct
# 1966 17 Apr to 16 Oct
# 1967 16 Apr to 22 Oct
# 1968 21 Apr to 20 Oct
# 1969 20 Apr to 19 Oct
# 1970 19 Apr to 18 Oct
# 1971 18 Apr to 17 Oct
# 1972 16 Apr to 22 Oct
# 1973 22 Apr to 21 Oct
# 1973/74 30 Dec 73 to 20 Oct 74
# 1975 20 Apr to 19 Oct
# 1976 18 Apr to 17 Oct
# 1977 Nil
# 1978 Nil
# 1979 13 May to 21 Oct
# 1980 to Now Nil
# The page does not give times of day for transitions,
# or dates for the 1942 and 1945 transitions.
# The Japanese occupation of Hong Kong began 1941-12-25.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule HK 1946 only - Apr 21 0:00 1:00 S
Rule HK 1946 only - Dec 1 3:30s 0 -
Rule HK 1947 only - Apr 13 3:30s 1:00 S
Rule HK 1947 only - Nov 30 3:30s 0 -
Rule HK 1948 only - May 2 3:30s 1:00 S
Rule HK 1948 1952 - Oct Sun>=28 3:30s 0 -
Rule HK 1949 1953 - Apr Sun>=1 3:30 1:00 S
Rule HK 1953 1964 - Oct Sun>=31 3:30 0 -
Rule HK 1954 1964 - Mar Sun>=18 3:30 1:00 S
Rule HK 1965 1976 - Apr Sun>=16 3:30 1:00 S
Rule HK 1965 1976 - Oct Sun>=16 3:30 0 -
Rule HK 1973 only - Dec 30 3:30 1:00 S
Rule HK 1979 only - May 13 3:30 1:00 S
Rule HK 1979 only - Oct 21 3:30 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Hong_Kong 7:36:42 - LMT 1904 Oct 30 0:36:42
8:00 - HKT 1941 Jun 15 3:00
8:00 1:00 HKST 1941 Oct 1 4:00
- 8:30 - HKT 1941 Dec 25
+ 8:00 0:30 HKWT 1941 Dec 25
9:00 - JST 1945 Nov 18 2:00
8:00 HK HK%sT
###############################################################################
# Taiwan
# From smallufo (2010-04-03):
# According to Taiwan's CWB [Central Weather Bureau],
# http://www.cwb.gov.tw/V6/astronomy/cdata/summert.htm
# Taipei has DST in 1979 between July 1st and Sep 30.
# From Yu-Cheng Chuang (2013-07-12):
# On Dec 28, 1895, the Meiji Emperor announced Ordinance No. 167 of
# Meiji Year 28 "The clause about standard time", mentioned that
# Taiwan and Penghu Islands, as well as Yaeyama and Miyako Islands
# (both in Okinawa) adopt the Western Standard Time which is based on
# 120E. The adoption began from Jan 1, 1896. The original text can be
# found on Wikisource:
# https://ja.wikisource.org/wiki/標準時ニ關スル件_(公布時)
# ... This could be the first adoption of time zone in Taiwan, because
# during the Qing Dynasty, it seems that there was no time zone
# declared officially.
#
# Later, in the beginning of World War II, on Sep 25, 1937, the Showa
# Emperor announced Ordinance No. 529 of Showa Year 12 "The clause of
# revision in the ordinance No. 167 of Meiji year 28 about standard
# time", in which abolished the adoption of Western Standard Time in
# western islands (listed above), which means the whole Japan
# territory, including later occupations, adopt Japan Central Time
# (UT+9). The adoption began on Oct 1, 1937. The original text can
# be found on Wikisource:
# https://ja.wikisource.org/wiki/明治二十八年勅令第百六十七號標準時ニ關スル件中改正ノ件
#
# That is, the time zone of Taipei switched to UT+9 on Oct 1, 1937.
# From Yu-Cheng Chuang (2014-07-02):
# I've found more evidence about when the time zone was switched from UT+9
# back to UT+8 after WW2. I believe it was on Sep 21, 1945. In a document
# during Japanese era [1] in which the officer told the staff to change time
# zone back to Western Standard Time (UT+8) on Sep 21. And in another
# history page of National Cheng Kung University [2], on Sep 21 there is a
# note "from today, switch back to Western Standard Time". From these two
# materials, I believe that the time zone change happened on Sep 21. And
# today I have found another monthly journal called "The Astronomical Herald"
# from The Astronomical Society of Japan [3] in which it mentioned the fact
# that:
#
# 1. Standard Time of the Country (Japan) was adopted on Jan 1, 1888, using
# the time at 135E (GMT+9)
#
# 2. Standard Time of the Country was renamed to Central Standard Time, on Jan
# 1, 1898, and on the same day, the new territories Taiwan and Penghu islands,
# as well as Yaeyama and Miyako islands, adopted a new time zone called
# Western Standard Time, which is in GMT+8.
#
# 3. Western Standard Time was deprecated on Sep 30, 1937. From then all the
# territories of Japan adopted the same time zone, which is Central Standard
# Time.
#
# [1] Academica Historica, Taiwan:
# http://163.29.208.22:8080/govsaleShowImage/connect_img.php?s=00101738900090036&e=00101738900090037
# [2] Nat'l Cheng Kung University 70th Anniversary Special Site:
# http://www.ncku.edu.tw/~ncku70/menu/001/01_01.htm
# [3] Yukio Niimi, The Standard Time in Japan (1997), p.475:
# http://www.asj.or.jp/geppou/archive_open/1997/pdf/19971001c.pdf
# Yu-Cheng Chuang (2014-07-03):
# I finally have found the real official gazette about changing back to
# Western Standard Time on Sep 21 in Taiwan. It's Taiwan Governor-General
# Bulletin No. 386 in Showa 20 years (1945), published on Sep 19, 1945. [1] ...
# [It] abolishes Bulletin No. 207 in Showa 12 years (1937), which is a local
# bulletin in Taiwan for that Ordinance No. 529. It also mentioned that 1am on
# Sep 21, 1945 will be 12am on Sep 21. I think this bulletin is much more
# official than the one I mentioned in my first mail, because it's from the
# top-level government in Taiwan. If you're going to quote any resource, this
# would be a good one.
# [1] Taiwan Governor-General Gazette, No. 1018, Sep 19, 1945:
# http://db2.th.gov.tw/db2/view/viewImg.php?imgcode=0072031018a&num=19&bgn=019&end=019&otherImg=&type=gener
# From Yu-Cheng Chuang (2014-07-02):
# In 1946, DST in Taiwan was from May 15 and ended on Sep 30. The info from
# Central Weather Bureau website was not correct.
#
# Original Bulletin:
# http://subtpg.tpg.gov.tw/og/image2.asp?f=03502F0AKM1AF
# http://subtpg.tpg.gov.tw/og/image2.asp?f=0350300AKM1B0 (cont.)
#
# In 1947, DST in Taiwan was expanded to Oct 31. There is a backup of that
# telegram announcement from Taiwan Province Government:
#
# http://subtpg.tpg.gov.tw/og/image2.asp?f=0360310AKZ431
#
# Here is a brief translation:
#
# The Summer Time this year is adopted from midnight Apr 15 until Sep 20
# midnight. To save (energy?) consumption, we're expanding Summer Time
# adoption till Oct 31 midnight.
#
# The Central Weather Bureau website didn't mention that, however it can
# be found from historical government announcement database.
# From Paul Eggert (2014-07-03):
# As per Yu-Cheng Chuang, say that Taiwan was at UT +09 from 1937-10-01
# until 1945-09-21 at 01:00, overriding Shanks & Pottenger.
# Likewise, use Yu-Cheng Chuang's data for DST in Taiwan.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Taiwan 1946 only - May 15 0:00 1:00 D
Rule Taiwan 1946 only - Oct 1 0:00 0 S
Rule Taiwan 1947 only - Apr 15 0:00 1:00 D
Rule Taiwan 1947 only - Nov 1 0:00 0 S
Rule Taiwan 1948 1951 - May 1 0:00 1:00 D
Rule Taiwan 1948 1951 - Oct 1 0:00 0 S
Rule Taiwan 1952 only - Mar 1 0:00 1:00 D
Rule Taiwan 1952 1954 - Nov 1 0:00 0 S
Rule Taiwan 1953 1959 - Apr 1 0:00 1:00 D
Rule Taiwan 1955 1961 - Oct 1 0:00 0 S
Rule Taiwan 1960 1961 - Jun 1 0:00 1:00 D
Rule Taiwan 1974 1975 - Apr 1 0:00 1:00 D
Rule Taiwan 1974 1975 - Oct 1 0:00 0 S
Rule Taiwan 1979 only - Jul 1 0:00 1:00 D
Rule Taiwan 1979 only - Oct 1 0:00 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
# Taipei or Taibei or T'ai-pei
Zone Asia/Taipei 8:06:00 - LMT 1896 Jan 1
8:00 - CST 1937 Oct 1
9:00 - JST 1945 Sep 21 1:00
8:00 Taiwan C%sT
# Macau (Macao, Aomen)
#
# From P Chan (2018-05-10):
# * LegisMac
# http://legismac.safp.gov.mo/legismac/descqry/Descqry.jsf?lang=pt
# A database for searching titles of legal documents of Macau in
# Chinese and Portuguese. The term "HORÁRIO DE VERÃO" can be used for
# searching decrees about summer time.
# * Archives of Macao
# http://www.archives.gov.mo/en/bo/
# It contains images of old official gazettes.
# * The Macao Meteorological and Geophysical Bureau have a page listing the
# summer time history. But it is not complete and has some mistakes.
# http://www.smg.gov.mo/smg/geophysics/e_t_Summer%20Time.htm
# Macau adopted GMT+8 on 30 Oct 1904 to follow Hong Kong. Clocks were
# advanced by 25 minutes and 50 seconds. Which means the LMT used was
# +7:34:10. As stated in the "Portaria No. 204" dated 21 October 1904
# and published in the Official Gazette on 29 October 1904.
# http://igallery.icm.gov.mo/Images/Archives/BO/MO_AH_PUB_BO_1904_10/MO_AH_PUB_BO_1904_10_00025_Grey.JPG
#
# Therefore the 1911 decree of Portugal did not change time in Macau.
#
# From LegisMac, here is a list of decrees that changed the time ...
# [Decree Gazette-no. date; titles omitted in this quotation]
# DIL 732 BOCM 51 1941.12.20
# DIL 764 BOCM 9S 1942.04.30
# DIL 781 BOCM 21 1942.10.10
# PT 3434 BOCM 8S 1943.04.17
# PT 3504 BOCM 20 1943.09.25
# PT 3843 BOCM 39 1945.09.29
# PT 3961 BOCM 17 1946.04.27
# PT 4026 BOCM 39 1946.09.28
# PT 4153 BOCM 16 1947.04.10
# PT 4271 BOCM 48 1947.11.29
# PT 4374 BOCM 18 1948.05.01
# PT 4465 BOCM 44 1948.10.30
# PT 4590 BOCM 14 1949.04.02
# PT 4666 BOCM 44 1949.10.29
# PT 4771 BOCM 12 1950.03.25
# PT 4838 BOCM 43 1950.10.28
# PT 4946 BOCM 12 1951.03.24
# PT 5025 BO 43 1951.10.27
# PT 5149 BO 14 1952.04.05
# PT 5251 BO 43 1952.10.25
# PT 5366 BO 13 1953.03.28
# PT 5444 BO 44 1953.10.31
# PT 5540 BO 12 1954.03.20
# PT 5589 BO 44 1954.10.30
# PT 5676 BO 12 1955.03.19
# PT 5739 BO 45 1955.11.05
# PT 5823 BO 11 1956.03.17
# PT 5891 BO 44 1956.11.03
# PT 5981 BO 12 1957.03.23
# PT 6064 BO 43 1957.10.26
# PT 6172 BO 12 1958.03.22
# PT 6243 BO 43 1958.10.25
# PT 6341 BO 12 1959.03.21
# PT 6411 BO 43 1959.10.24
# PT 6514 BO 11 1960.03.12
# PT 6584 BO 44 1960.10.29
# PT 6721 BO 10 1961.03.11
# PT 6815 BO 43 1961.10.28
# PT 6947 BO 10 1962.03.10
# PT 7080 BO 43 1962.10.27
# PT 7218 BO 12 1963.03.23
# PT 7340 BO 43 1963.10.26
# PT 7491 BO 11 1964.03.14
# PT 7664 BO 43 1964.10.24
# PT 7846 BO 15 1965.04.10
# PT 7979 BO 42 1965.10.16
# PT 8146 BO 15 1966.04.09
# PT 8252 BO 41 1966.10.08
# PT 8429 BO 15 1967.04.15
# PT 8540 BO 41 1967.10.14
# PT 8735 BO 15 1968.04.13
# PT 8860 BO 41 1968.10.12
# PT 9035 BO 16 1969.04.19
# PT 9156 BO 42 1969.10.18
# PT 9328 BO 15 1970.04.11
# PT 9418 BO 41 1970.10.10
# PT 9587 BO 14 1971.04.03
# PT 9702 BO 41 1971.10.09
# PT 38-A/72 BO 14 1972.04.01
# PT 126-A/72 BO 41 1972.10.07
# PT 61/73 BO 14 1973.04.07
# PT 182/73 BO 40 1973.10.06
# PT 282/73 BO 51 1973.12.22
# PT 177/74 BO 41 1974.10.12
# PT 51/75 BO 15 1975.04.12
# PT 173/75 BO 41 1975.10.11
# PT 67/76/M BO 14 1976.04.03
# PT 169/76/M BO 41 1976.10.09
# PT 78/79/M BO 19 1979.05.12
# PT 166/79/M BO 42 1979.10.20
# Note that DIL 732 does not belong to "HORÁRIO DE VERÃO" according to
# LegisMac.... Note that between 1942 and 1945, the time switched
# between GMT+9 and GMT+10. Also in 1965 and 1965 the DST ended at 2:30am.
# From Paul Eggert (2018-05-10):
# The 1904 decree says that Macau changed from the meridian of
# Fortaleza do Monte, presumably the basis for the 7:34:10 for LMT.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Macau 1942 1943 - Apr 30 23:00 1:00 -
Rule Macau 1942 only - Nov 17 23:00 0 -
Rule Macau 1943 only - Sep 30 23:00 0 S
Rule Macau 1946 only - Apr 30 23:00s 1:00 D
Rule Macau 1946 only - Sep 30 23:00s 0 S
Rule Macau 1947 only - Apr 19 23:00s 1:00 D
Rule Macau 1947 only - Nov 30 23:00s 0 S
Rule Macau 1948 only - May 2 23:00s 1:00 D
Rule Macau 1948 only - Oct 31 23:00s 0 S
Rule Macau 1949 1950 - Apr Sat>=1 23:00s 1:00 D
Rule Macau 1949 1950 - Oct lastSat 23:00s 0 S
Rule Macau 1951 only - Mar 31 23:00s 1:00 D
Rule Macau 1951 only - Oct 28 23:00s 0 S
Rule Macau 1952 1953 - Apr Sat>=1 23:00s 1:00 D
Rule Macau 1952 only - Nov 1 23:00s 0 S
Rule Macau 1953 1954 - Oct lastSat 23:00s 0 S
Rule Macau 1954 1956 - Mar Sat>=17 23:00s 1:00 D
Rule Macau 1955 only - Nov 5 23:00s 0 S
Rule Macau 1956 1964 - Nov Sun>=1 03:30 0 S
Rule Macau 1957 1964 - Mar Sun>=18 03:30 1:00 D
Rule Macau 1965 1973 - Apr Sun>=16 03:30 1:00 D
Rule Macau 1965 1966 - Oct Sun>=16 02:30 0 S
Rule Macau 1967 1976 - Oct Sun>=16 03:30 0 S
Rule Macau 1973 only - Dec 30 03:30 1:00 D
Rule Macau 1975 1976 - Apr Sun>=16 03:30 1:00 D
Rule Macau 1979 only - May 13 03:30 1:00 D
Rule Macau 1979 only - Oct Sun>=16 03:30 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Macau 7:34:10 - LMT 1904 Oct 30
8:00 - CST 1941 Dec 21 23:00
9:00 Macau +09/+10 1945 Sep 30 24:00
8:00 Macau C%sT
###############################################################################
# Cyprus
# Milne says the Eastern Telegraph Company used 2:14:00. Stick with LMT.
# IATA SSIM (1998-09) has Cyprus using EU rules for the first time.
# From Paul Eggert (2016-09-09):
# Yesterday's Cyprus Mail reports that Northern Cyprus followed Turkey's
# lead and switched from +02/+03 to +03 year-round.
# http://cyprus-mail.com/2016/09/08/two-time-zones-cyprus-turkey-will-not-turn-clocks-back-next-month/
#
# From Even Scharning (2016-10-31):
# Looks like the time zone split in Cyprus went through last night.
# http://cyprus-mail.com/2016/10/30/cyprus-new-division-two-time-zones-now-reality/
# From Paul Eggert (2017-10-18):
# Northern Cyprus will reinstate winter time on October 29, thus
# staying in sync with the rest of Cyprus. See: Anastasiou A.
# Cyprus to remain united in time. Cyprus Mail 2017-10-17.
# https://cyprus-mail.com/2017/10/17/cyprus-remain-united-time/
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Cyprus 1975 only - Apr 13 0:00 1:00 S
Rule Cyprus 1975 only - Oct 12 0:00 0 -
Rule Cyprus 1976 only - May 15 0:00 1:00 S
Rule Cyprus 1976 only - Oct 11 0:00 0 -
Rule Cyprus 1977 1980 - Apr Sun>=1 0:00 1:00 S
Rule Cyprus 1977 only - Sep 25 0:00 0 -
Rule Cyprus 1978 only - Oct 2 0:00 0 -
Rule Cyprus 1979 1997 - Sep lastSun 0:00 0 -
Rule Cyprus 1981 1998 - Mar lastSun 0:00 1:00 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Nicosia 2:13:28 - LMT 1921 Nov 14
2:00 Cyprus EE%sT 1998 Sep
2:00 EUAsia EE%sT
Zone Asia/Famagusta 2:15:48 - LMT 1921 Nov 14
2:00 Cyprus EE%sT 1998 Sep
2:00 EUAsia EE%sT 2016 Sep 8
3:00 - +03 2017 Oct 29 1:00u
2:00 EUAsia EE%sT
# Classically, Cyprus belongs to Asia; e.g. see Herodotus, Histories, I.72.
# However, for various reasons many users expect to find it under Europe.
Link Asia/Nicosia Europe/Nicosia
# Georgia
# From Paul Eggert (1994-11-19):
# Today's _Economist_ (p 60) reports that Georgia moved its clocks forward
# an hour recently, due to a law proposed by Zurab Murvanidze,
# an MP who went on a hunger strike for 11 days to force discussion about it!
# We have no details, but we'll guess they didn't move the clocks back in fall.
#
# From Mathew Englander, quoting AP (1996-10-23 13:05-04):
# Instead of putting back clocks at the end of October, Georgia
# will stay on daylight savings time this winter to save energy,
# President Eduard Shevardnadze decreed Wednesday.
#
# From the BBC via Joseph S. Myers (2004-06-27):
#
# Georgia moved closer to Western Europe on Sunday... The former Soviet
# republic has changed its time zone back to that of Moscow. As a result it
# is now just four hours ahead of Greenwich Mean Time, rather than five hours
# ahead. The switch was decreed by the pro-Western president of Georgia,
# Mikheil Saakashvili, who said the change was partly prompted by the process
# of integration into Europe.
# From Teimuraz Abashidze (2005-11-07):
# Government of Georgia ... decided to NOT CHANGE daylight savings time on
# [Oct.] 30, as it was done before during last more than 10 years.
# Currently, we are in fact GMT +4:00, as before 30 October it was GMT
# +3:00.... The problem is, there is NO FORMAL LAW or governmental document
# about it. As far as I can find, I was told, that there is no document,
# because we just DIDN'T ISSUE document about switching to winter time....
# I don't know what can be done, especially knowing that some years ago our
# DST rules where changed THREE TIMES during one month.
# Milne 1899 says Tbilisi (Tiflis) time was 2:59:05.7.
# Byalokoz 1919 says Georgia was 2:59:11.
# Go with Byalokoz.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Tbilisi 2:59:11 - LMT 1880
2:59:11 - TBMT 1924 May 2 # Tbilisi Mean Time
3:00 - +03 1957 Mar
4:00 RussiaAsia +04/+05 1991 Mar 31 2:00s
3:00 RussiaAsia +03/+04 1992
3:00 E-EurAsia +03/+04 1994 Sep lastSun
4:00 E-EurAsia +04/+05 1996 Oct lastSun
4:00 1:00 +05 1997 Mar lastSun
4:00 E-EurAsia +04/+05 2004 Jun 27
3:00 RussiaAsia +03/+04 2005 Mar lastSun 2:00
4:00 - +04
# East Timor
# See Indonesia for the 1945 transition.
# From João Carrascalão, brother of the former governor of East Timor, in
# East Timor may be late for its millennium
# <https://etan.org/et99c/december/26-31/30ETMAY.htm> (1999-12-26/31):
# Portugal tried to change the time forward in 1974 because the sun
# rises too early but the suggestion raised a lot of problems with the
# Timorese and I still don't think it would work today because it
# conflicts with their way of life.
# From Paul Eggert (2000-12-04):
# We don't have any record of the above attempt.
# Most likely our records are incomplete, but we have no better data.
# From Manoel de Almeida e Silva, Deputy Spokesman for the UN Secretary-General
# http://www.hri.org/news/world/undh/2000/00-08-16.undh.html
# (2000-08-16):
# The Cabinet of the East Timor Transition Administration decided
# today to advance East Timor's time by one hour. The time change,
# which will be permanent, with no seasonal adjustment, will happen at
# midnight on Saturday, September 16.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Dili 8:22:20 - LMT 1912 Jan 1
8:00 - +08 1942 Feb 21 23:00
9:00 - +09 1976 May 3
8:00 - +08 2000 Sep 17 0:00
9:00 - +09
# India
# British astronomer Henry Park Hollis disliked India Standard Time's offset:
# "A new time system has been proposed for India, Further India, and Burmah.
# The scheme suggested is that the times of the meridians 5½ and 6½ hours
# east of Greenwich should be adopted in these territories. No reason is
# given why hourly meridians five hours and six hours east should not be
# chosen; a plan which would bring the time of India into harmony with
# that of almost the whole of the civilised world."
# Hollis HP. Universal Time, Longitudes, and Geodesy. Mon Not R Astron Soc.
# 1905-02-10;65(4):405-6. https://doi.org/10.1093/mnras/65.4.382
# From Ian P. Beacock, in "A brief history of (modern) time", The Atlantic
# https://www.theatlantic.com/technology/archive/2015/12/the-creation-of-modern-time/421419/
# (2015-12-22):
# In January 1906, several thousand cotton-mill workers rioted on the
# outskirts of Bombay.... They were protesting the proposed abolition of
# local time in favor of Indian Standard Time.... Journalists called this
# dispute the "Battle of the Clocks." It lasted nearly half a century.
# From Paul Eggert (2017-04-20):
# Good luck trying to nail down old timekeeping records in India.
# "... in the nineteenth century ... Madras Observatory took its magnetic
# measurements on Göttingen time, its meteorological measurements on Madras
# (local) time, dropped its time ball on Greenwich (ocean navigator's) time,
# and distributed civil (local time)." -- Bartky IR. Selling the true time:
# 19th-century timekeeping in america. Stanford U Press (2000), 247 note 19.
# "A more potent cause of resistance to the general adoption of the present
# standard time lies in the fact that it is Madras time. The citizen of
# Bombay, proud of being 'primus in Indis' and of Calcutta, equally proud of
# his city being the Capital of India, and - for a part of the year - the Seat
# of the Supreme Government, alike look down on Madras, and refuse to change
# the time they are using, for that of what they regard as a benighted
# Presidency; while Madras, having for long given the standard time to the
# rest of India, would resist the adoption of any other Indian standard in its
# place." -- Oldham RD. On Time in India: a suggestion for its improvement.
# Proceedings of the Asiatic Society of Bengal (April 1899), 49-55.
#
# "In 1870 ... Madras time - 'now used by the telegraph and regulated from the
# only government observatory' - was suggested as a standard railway time,
# first to be adopted on the Great Indian Peninsular Railway (GIPR)....
# Calcutta, Bombay, and Karachi, were to be allowed to continue with their
# local time for civil purposes." - Prasad R. Tracks of Change: Railways and
# Everyday Life in Colonial India. Cambridge University Press (2016), 145.
#
# Reed S, Low F. The Indian Year Book 1936-37. Bennett, Coleman, pp 27-8.
# https://archive.org/details/in.ernet.dli.2015.282212
# This lists +052110 as Madras local time used in railways, and says that on
# 1906-01-01 railways and telegraphs in India switched to +0530. Some
# municipalities retained their former time, and the time in Calcutta
# continued to depend on whether you were at the railway station or at
# government offices. Government time was at +055320 (according to Shanks) or
# at +0554 (according to the Indian Year Book). Railway time is more
# appropriate for our purposes, as it was better documented, it is what we do
# elsewhere (e.g., Europe/London before 1880), and after 1906 it was
# consistent in the region now identified by Asia/Kolkata. So, use railway
# time for 1870-1941. Shanks is our only (and dubious) source for the
# 1941-1945 data.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Kolkata 5:53:28 - LMT 1854 Jun 28 # Kolkata
5:53:20 - HMT 1870 # Howrah Mean Time?
5:21:10 - MMT 1906 Jan 1 # Madras local time
5:30 - IST 1941 Oct
5:30 1:00 +0630 1942 May 15
5:30 - IST 1942 Sep
5:30 1:00 +0630 1945 Oct 15
5:30 - IST
# Since 1970 the following are like Asia/Kolkata:
# Andaman Is
# Lakshadweep (Laccadive, Minicoy and Amindivi Is)
# Nicobar Is
# Indonesia
#
# From Paul Eggert (2014-09-06):
# The 1876 Report of the Secretary of the [US] Navy, p 306 says that Batavia
# civil time was 7:07:12.5; round to even for Jakarta.
#
# From Gwillim Law (2001-05-28), overriding Shanks & Pottenger:
# http://www.sumatera-inc.com/go_to_invest/about_indonesia.asp#standtime
# says that Indonesia's time zones changed on 1988-01-01. Looking at some
# time zone maps, I think that must refer to Western Borneo (Kalimantan Barat
# and Kalimantan Tengah) switching from UTC+8 to UTC+7.
#
# From Paul Eggert (2007-03-10):
# Here is another correction to Shanks & Pottenger.
# JohnTWB writes that Japanese forces did not surrender control in
# Indonesia until 1945-09-01 00:00 at the earliest (in Jakarta) and
# other formal surrender ceremonies were September 9, 11, and 13, plus
# September 12 for the regional surrender to Mountbatten in Singapore.
# These would be the earliest possible times for a change.
# Régimes horaires pour le monde entier, by Henri Le Corre, (Éditions
# Traditionnelles, 1987, Paris) says that Java and Madura switched
# from UT +09 to +07:30 on 1945-09-23, and gives 1944-09-01 for Jayapura
# (Hollandia). For now, assume all Indonesian locations other than Jayapura
# switched on 1945-09-23.
#
# From Paul Eggert (2013-08-11):
# Normally the tz database uses English-language abbreviations, but in
# Indonesia it's typical to use Indonesian-language abbreviations even
# when writing in English. For example, see the English-language
# summary published by the Time and Frequency Laboratory of the
# Research Center for Calibration, Instrumentation and Metrology,
# Indonesia, <http://time.kim.lipi.go.id/time-eng.php> (2006-09-29).
# The time zone abbreviations and UT offsets are:
#
# WIB - +07 - Waktu Indonesia Barat (Indonesia western time)
# WITA - +08 - Waktu Indonesia Tengah (Indonesia central time)
# WIT - +09 - Waktu Indonesia Timur (Indonesia eastern time)
#
# Zone NAME STDOFF RULES FORMAT [UNTIL]
# Java, Sumatra
Zone Asia/Jakarta 7:07:12 - LMT 1867 Aug 10
# Shanks & Pottenger say the next transition was at 1924 Jan 1 0:13,
# but this must be a typo.
7:07:12 - BMT 1923 Dec 31 23:47:12 # Batavia
7:20 - +0720 1932 Nov
7:30 - +0730 1942 Mar 23
9:00 - +09 1945 Sep 23
7:30 - +0730 1948 May
8:00 - +08 1950 May
7:30 - +0730 1964
7:00 - WIB
# west and central Borneo
Zone Asia/Pontianak 7:17:20 - LMT 1908 May
7:17:20 - PMT 1932 Nov # Pontianak MT
7:30 - +0730 1942 Jan 29
9:00 - +09 1945 Sep 23
7:30 - +0730 1948 May
8:00 - +08 1950 May
7:30 - +0730 1964
8:00 - WITA 1988 Jan 1
7:00 - WIB
# Sulawesi, Lesser Sundas, east and south Borneo
Zone Asia/Makassar 7:57:36 - LMT 1920
7:57:36 - MMT 1932 Nov # Macassar MT
8:00 - +08 1942 Feb 9
9:00 - +09 1945 Sep 23
8:00 - WITA
# Maluku Islands, West Papua, Papua
Zone Asia/Jayapura 9:22:48 - LMT 1932 Nov
9:00 - +09 1944 Sep 1
9:30 - +0930 1964
9:00 - WIT
# Iran
# From Roozbeh Pournader (2003-03-15):
# This is an English translation of what I just found (originally in Persian).
# The Gregorian dates in brackets are mine:
#
# Official Newspaper No. 13548-1370/6/25 [1991-09-16]
# No. 16760/T233 H 1370/6/10 [1991-09-01]
#
# The Rule About Change of the Official Time of the Country
#
# The Board of Ministers, in the meeting dated 1370/5/23 [1991-08-14],
# based on the suggestion number 2221/D dated 1370/4/22 [1991-07-13]
# of the Country's Organization for Official and Employment Affairs,
# and referring to the law for equating the working hours of workers
# and officers in the whole country dated 1359/4/23 [1980-07-14], and
# for synchronizing the official times of the country, agreed that:
#
# The official time of the country will should move forward one hour
# at the 24[:00] hours of the first day of Farvardin and should return
# to its previous state at the 24[:00] hours of the 30th day of
# Shahrivar.
#
# First Deputy to the President - Hassan Habibi
#
# From personal experience, that agrees with what has been followed
# for at least the last 5 years. Before that, for a few years, the
# date used was the first Thursday night of Farvardin and the last
# Thursday night of Shahrivar, but I can't give exact dates....
#
# From Roozbeh Pournader (2005-04-05):
# The text of the Iranian law, in effect since 1925, clearly mentions
# that the true solar year is the measure, and there is no arithmetic
# leap year calculation involved. There has never been any serious
# plan to change that law....
#
# From Paul Eggert (2018-11-30):
# Go with Shanks & Pottenger before Sept. 1991, and with Pournader thereafter.
# I used the following code in GNU Emacs 26.1 to generate the "Rule Iran"
# lines from 2008 through 2087. Emacs 26.1 uses Ed Reingold's
# cal-persia implementation of Birashk's approximation, which in the
# 2008-2087 range disagrees with the astronomical Persian calendar
# for Persian years 1404 (Gregorian 2025) and 1437 (Gregorian 2058), so
# the following code special-cases those years. See Table 15.1, page 264, of:
# Edward M. Reingold and Nachum Dershowitz, Calendrical Calculations:
# The Ultimate Edition, Cambridge University Press (2018).
# https://www.cambridge.org/fr/academic/subjects/computer-science/computing-general-interest/calendrical-calculations-ultimate-edition-4th-edition
# Page 258, footnote 2, of this book says there is some dispute over what will
# happen in 2091 (and some other years after that), so this code
# stops in 2087, as 2088 and 2089 agree with the "max" rule below.
# (cl-loop
# initially (require 'cal-persia)
# with first-persian-year = 1387
# with last-persian-year = 1466
# ;; Exceptional years in the above range,
# ;; from Reingold & Dershowitz Table 15.1, page 264:
# with exceptional-persian-years = '(1404 1437)
# with range-start = nil
# for persian-year from first-persian-year to last-persian-year
# do
# (let*
# ((exceptional-year-offset
# (if (member persian-year exceptional-persian-years) 1 0))
# (beg-dst-absolute
# (+ (calendar-persian-to-absolute (list 1 1 persian-year))
# exceptional-year-offset))
# (end-dst-absolute
# (+ (calendar-persian-to-absolute (list 6 30 persian-year))
# exceptional-year-offset))
# (next-year-beg-dst-absolute
# (+ (calendar-persian-to-absolute (list 1 1 (1+ persian-year)))
# (if (member (1+ persian-year) exceptional-persian-years) 1 0)))
# (beg-dst (calendar-gregorian-from-absolute beg-dst-absolute))
# (end-dst (calendar-gregorian-from-absolute end-dst-absolute))
# (next-year-beg-dst (calendar-gregorian-from-absolute
# next-year-beg-dst-absolute))
# (year (calendar-extract-year beg-dst))
# (range-end (if range-start year "only")))
# (setq range-start (or range-start year))
# (when (or (/= (calendar-extract-day beg-dst)
# (calendar-extract-day next-year-beg-dst))
# (= persian-year last-persian-year))
# (insert
# (format
# "Rule\tIran\t%d\t%s\t-\t%s\t%2d\t24:00\t1:00\t-\n"
# range-start range-end
# (calendar-month-name (calendar-extract-month beg-dst) t)
# (calendar-extract-day beg-dst)))
# (insert
# (format
# "Rule\tIran\t%d\t%s\t-\t%s\t%2d\t24:00\t0\t-\n"
# range-start range-end
# (calendar-month-name (calendar-extract-month end-dst) t)
# (calendar-extract-day end-dst)))
# (setq range-start nil))))
#
# From Oscar van Vlijmen (2005-03-30), writing about future
# discrepancies between cal-persia and the Iranian calendar:
# For 2091 solar-longitude-after yields 2091-03-20 08:40:07.7 UT for
# the vernal equinox and that gets so close to 12:00 some local
# Iranian time that the definition of the correct location needs to be
# known exactly, amongst other factors. 2157 is even closer:
# 2157-03-20 08:37:15.5 UT. But the Gregorian year 2025 should give
# no interpretation problem whatsoever. By the way, another instant
# in the near future where there will be a discrepancy between
# arithmetical and astronomical Iranian calendars will be in 2058:
# vernal equinox on 2058-03-20 09:03:05.9 UT. The Java version of
# Reingold's/Dershowitz' calculator gives correctly the Gregorian date
# 2058-03-21 for 1 Farvardin 1437 (astronomical).
#
# From Steffen Thorsen (2006-03-22):
# Several of my users have reported that Iran will not observe DST anymore:
# http://www.irna.ir/en/news/view/line-17/0603193812164948.htm
#
# From Reuters (2007-09-16), with a heads-up from Jesper Nørgaard Welen:
# ... the Guardian Council ... approved a law on Sunday to re-introduce
# daylight saving time ...
# https://uk.reuters.com/article/oilRpt/idUKBLA65048420070916
#
# From Roozbeh Pournader (2007-11-05):
# This is quoted from Official Gazette of the Islamic Republic of
# Iran, Volume 63, No. 18242, dated Tuesday 1386/6/24
# [2007-10-16]. I am doing the best translation I can:...
# The official time of the country will be moved forward for one hour
# on the 24 hours of the first day of the month of Farvardin and will
# be changed back to its previous state on the 24 hours of the
# thirtieth day of Shahrivar.
#
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Iran 1978 1980 - Mar 20 24:00 1:00 -
Rule Iran 1978 only - Oct 20 24:00 0 -
Rule Iran 1979 only - Sep 18 24:00 0 -
Rule Iran 1980 only - Sep 22 24:00 0 -
Rule Iran 1991 only - May 2 24:00 1:00 -
Rule Iran 1992 1995 - Mar 21 24:00 1:00 -
Rule Iran 1991 1995 - Sep 21 24:00 0 -
Rule Iran 1996 only - Mar 20 24:00 1:00 -
Rule Iran 1996 only - Sep 20 24:00 0 -
Rule Iran 1997 1999 - Mar 21 24:00 1:00 -
Rule Iran 1997 1999 - Sep 21 24:00 0 -
Rule Iran 2000 only - Mar 20 24:00 1:00 -
Rule Iran 2000 only - Sep 20 24:00 0 -
Rule Iran 2001 2003 - Mar 21 24:00 1:00 -
Rule Iran 2001 2003 - Sep 21 24:00 0 -
Rule Iran 2004 only - Mar 20 24:00 1:00 -
Rule Iran 2004 only - Sep 20 24:00 0 -
Rule Iran 2005 only - Mar 21 24:00 1:00 -
Rule Iran 2005 only - Sep 21 24:00 0 -
Rule Iran 2008 only - Mar 20 24:00 1:00 -
Rule Iran 2008 only - Sep 20 24:00 0 -
Rule Iran 2009 2011 - Mar 21 24:00 1:00 -
Rule Iran 2009 2011 - Sep 21 24:00 0 -
Rule Iran 2012 only - Mar 20 24:00 1:00 -
Rule Iran 2012 only - Sep 20 24:00 0 -
Rule Iran 2013 2015 - Mar 21 24:00 1:00 -
Rule Iran 2013 2015 - Sep 21 24:00 0 -
Rule Iran 2016 only - Mar 20 24:00 1:00 -
Rule Iran 2016 only - Sep 20 24:00 0 -
Rule Iran 2017 2019 - Mar 21 24:00 1:00 -
Rule Iran 2017 2019 - Sep 21 24:00 0 -
Rule Iran 2020 only - Mar 20 24:00 1:00 -
Rule Iran 2020 only - Sep 20 24:00 0 -
Rule Iran 2021 2023 - Mar 21 24:00 1:00 -
Rule Iran 2021 2023 - Sep 21 24:00 0 -
Rule Iran 2024 only - Mar 20 24:00 1:00 -
Rule Iran 2024 only - Sep 20 24:00 0 -
Rule Iran 2025 2027 - Mar 21 24:00 1:00 -
Rule Iran 2025 2027 - Sep 21 24:00 0 -
Rule Iran 2028 2029 - Mar 20 24:00 1:00 -
Rule Iran 2028 2029 - Sep 20 24:00 0 -
Rule Iran 2030 2031 - Mar 21 24:00 1:00 -
Rule Iran 2030 2031 - Sep 21 24:00 0 -
Rule Iran 2032 2033 - Mar 20 24:00 1:00 -
Rule Iran 2032 2033 - Sep 20 24:00 0 -
Rule Iran 2034 2035 - Mar 21 24:00 1:00 -
Rule Iran 2034 2035 - Sep 21 24:00 0 -
Rule Iran 2036 2037 - Mar 20 24:00 1:00 -
Rule Iran 2036 2037 - Sep 20 24:00 0 -
Rule Iran 2038 2039 - Mar 21 24:00 1:00 -
Rule Iran 2038 2039 - Sep 21 24:00 0 -
Rule Iran 2040 2041 - Mar 20 24:00 1:00 -
Rule Iran 2040 2041 - Sep 20 24:00 0 -
Rule Iran 2042 2043 - Mar 21 24:00 1:00 -
Rule Iran 2042 2043 - Sep 21 24:00 0 -
Rule Iran 2044 2045 - Mar 20 24:00 1:00 -
Rule Iran 2044 2045 - Sep 20 24:00 0 -
Rule Iran 2046 2047 - Mar 21 24:00 1:00 -
Rule Iran 2046 2047 - Sep 21 24:00 0 -
Rule Iran 2048 2049 - Mar 20 24:00 1:00 -
Rule Iran 2048 2049 - Sep 20 24:00 0 -
Rule Iran 2050 2051 - Mar 21 24:00 1:00 -
Rule Iran 2050 2051 - Sep 21 24:00 0 -
Rule Iran 2052 2053 - Mar 20 24:00 1:00 -
Rule Iran 2052 2053 - Sep 20 24:00 0 -
Rule Iran 2054 2055 - Mar 21 24:00 1:00 -
Rule Iran 2054 2055 - Sep 21 24:00 0 -
Rule Iran 2056 2057 - Mar 20 24:00 1:00 -
Rule Iran 2056 2057 - Sep 20 24:00 0 -
Rule Iran 2058 2059 - Mar 21 24:00 1:00 -
Rule Iran 2058 2059 - Sep 21 24:00 0 -
Rule Iran 2060 2062 - Mar 20 24:00 1:00 -
Rule Iran 2060 2062 - Sep 20 24:00 0 -
Rule Iran 2063 only - Mar 21 24:00 1:00 -
Rule Iran 2063 only - Sep 21 24:00 0 -
Rule Iran 2064 2066 - Mar 20 24:00 1:00 -
Rule Iran 2064 2066 - Sep 20 24:00 0 -
Rule Iran 2067 only - Mar 21 24:00 1:00 -
Rule Iran 2067 only - Sep 21 24:00 0 -
Rule Iran 2068 2070 - Mar 20 24:00 1:00 -
Rule Iran 2068 2070 - Sep 20 24:00 0 -
Rule Iran 2071 only - Mar 21 24:00 1:00 -
Rule Iran 2071 only - Sep 21 24:00 0 -
Rule Iran 2072 2074 - Mar 20 24:00 1:00 -
Rule Iran 2072 2074 - Sep 20 24:00 0 -
Rule Iran 2075 only - Mar 21 24:00 1:00 -
Rule Iran 2075 only - Sep 21 24:00 0 -
Rule Iran 2076 2078 - Mar 20 24:00 1:00 -
Rule Iran 2076 2078 - Sep 20 24:00 0 -
Rule Iran 2079 only - Mar 21 24:00 1:00 -
Rule Iran 2079 only - Sep 21 24:00 0 -
Rule Iran 2080 2082 - Mar 20 24:00 1:00 -
Rule Iran 2080 2082 - Sep 20 24:00 0 -
Rule Iran 2083 only - Mar 21 24:00 1:00 -
Rule Iran 2083 only - Sep 21 24:00 0 -
Rule Iran 2084 2086 - Mar 20 24:00 1:00 -
Rule Iran 2084 2086 - Sep 20 24:00 0 -
Rule Iran 2087 only - Mar 21 24:00 1:00 -
Rule Iran 2087 only - Sep 21 24:00 0 -
#
# The following rules are approximations starting in the year 2088.
# These are the best post-2088 approximations available, given the
# restrictions of a single rule using ordinary Gregorian dates.
# At some point this table will need to be extended, though quite
# possibly Iran will change the rules first.
Rule Iran 2088 max - Mar 20 24:00 1:00 -
Rule Iran 2088 max - Sep 20 24:00 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Tehran 3:25:44 - LMT 1916
3:25:44 - TMT 1946 # Tehran Mean Time
3:30 - +0330 1977 Nov
4:00 Iran +04/+05 1979
3:30 Iran +0330/+0430
# Iraq
#
# From Jonathan Lennox (2000-06-12):
# An article in this week's Economist ("Inside the Saddam-free zone", p. 50 in
# the U.S. edition) on the Iraqi Kurds contains a paragraph:
# "The three northern provinces ... switched their clocks this spring and
# are an hour ahead of Baghdad."
#
# But Rives McDow (2000-06-18) quotes a contact in Iraqi-Kurdistan as follows:
# In the past, some Kurdish nationalists, as a protest to the Iraqi
# Government, did not adhere to daylight saving time. They referred
# to daylight saving as Saddam time. But, as of today, the time zone
# in Iraqi-Kurdistan is on standard time with Baghdad, Iraq.
#
# So we'll ignore the Economist's claim.
# From Steffen Thorsen (2008-03-10):
# The cabinet in Iraq abolished DST last week, according to the following
# news sources (in Arabic):
# http://www.aljeeran.net/wesima_articles/news-20080305-98602.html
# http://www.aswataliraq.info/look/article.tpl?id=2047&IdLanguage=17&IdPublication=4&NrArticle=71743&NrIssue=1&NrSection=10
#
# We have published a short article in English about the change:
# https://www.timeanddate.com/news/time/iraq-dumps-daylight-saving.html
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Iraq 1982 only - May 1 0:00 1:00 -
Rule Iraq 1982 1984 - Oct 1 0:00 0 -
Rule Iraq 1983 only - Mar 31 0:00 1:00 -
Rule Iraq 1984 1985 - Apr 1 0:00 1:00 -
Rule Iraq 1985 1990 - Sep lastSun 1:00s 0 -
Rule Iraq 1986 1990 - Mar lastSun 1:00s 1:00 -
# IATA SSIM (1991/1996) says Apr 1 12:01am UTC; guess the ':01' is a typo.
# Shanks & Pottenger say Iraq did not observe DST 1992/1997; ignore this.
#
Rule Iraq 1991 2007 - Apr 1 3:00s 1:00 -
Rule Iraq 1991 2007 - Oct 1 3:00s 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Baghdad 2:57:40 - LMT 1890
2:57:36 - BMT 1918 # Baghdad Mean Time?
3:00 - +03 1982 May
3:00 Iraq +03/+04
###############################################################################
# Israel
# From Ephraim Silverberg (2001-01-11):
#
# I coined "IST/IDT" circa 1988. Until then there were three
# different abbreviations in use:
#
# JST Jerusalem Standard Time [Danny Braniss, Hebrew University]
# IZT Israel Zonal (sic) Time [Prof. Haim Papo, Technion]
# EEST Eastern Europe Standard Time [used by almost everyone else]
#
# Since timezones should be called by country and not capital cities,
# I ruled out JST. As Israel is in Asia Minor and not Eastern Europe,
# EEST was equally unacceptable. Since "zonal" was not compatible with
# any other timezone abbreviation, I felt that 'IST' was the way to go
# and, indeed, it has received almost universal acceptance in timezone
# settings in Israeli computers.
#
# In any case, I am happy to share timezone abbreviations with India,
# high on my favorite-country list (and not only because my wife's
# family is from India).
# From Shanks & Pottenger:
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Zion 1940 only - Jun 1 0:00 1:00 D
Rule Zion 1942 1944 - Nov 1 0:00 0 S
Rule Zion 1943 only - Apr 1 2:00 1:00 D
Rule Zion 1944 only - Apr 1 0:00 1:00 D
Rule Zion 1945 only - Apr 16 0:00 1:00 D
Rule Zion 1945 only - Nov 1 2:00 0 S
Rule Zion 1946 only - Apr 16 2:00 1:00 D
Rule Zion 1946 only - Nov 1 0:00 0 S
Rule Zion 1948 only - May 23 0:00 2:00 DD
Rule Zion 1948 only - Sep 1 0:00 1:00 D
Rule Zion 1948 1949 - Nov 1 2:00 0 S
Rule Zion 1949 only - May 1 0:00 1:00 D
Rule Zion 1950 only - Apr 16 0:00 1:00 D
Rule Zion 1950 only - Sep 15 3:00 0 S
Rule Zion 1951 only - Apr 1 0:00 1:00 D
Rule Zion 1951 only - Nov 11 3:00 0 S
Rule Zion 1952 only - Apr 20 2:00 1:00 D
Rule Zion 1952 only - Oct 19 3:00 0 S
Rule Zion 1953 only - Apr 12 2:00 1:00 D
Rule Zion 1953 only - Sep 13 3:00 0 S
Rule Zion 1954 only - Jun 13 0:00 1:00 D
Rule Zion 1954 only - Sep 12 0:00 0 S
Rule Zion 1955 only - Jun 11 2:00 1:00 D
Rule Zion 1955 only - Sep 11 0:00 0 S
Rule Zion 1956 only - Jun 3 0:00 1:00 D
Rule Zion 1956 only - Sep 30 3:00 0 S
Rule Zion 1957 only - Apr 29 2:00 1:00 D
Rule Zion 1957 only - Sep 22 0:00 0 S
Rule Zion 1974 only - Jul 7 0:00 1:00 D
Rule Zion 1974 only - Oct 13 0:00 0 S
Rule Zion 1975 only - Apr 20 0:00 1:00 D
Rule Zion 1975 only - Aug 31 0:00 0 S
# From Alois Treindl (2019-03-06):
# http://www.moin.gov.il/Documents/שעון%20קיץ/clock-50-years-7-2014.pdf
# From Isaac Starkman (2019-03-06):
# Summer time was in that period in 1980 and 1984, see
# https://www.ynet.co.il/articles/0,7340,L-3951073,00.html
# You can of course read it in translation.
# I checked the local newspapers for that years.
# It started on midnight and end at 01.00 am.
# From Paul Eggert (2019-03-06):
# Also see this thread about the moin.gov.il URL:
# https://mm.icann.org/pipermail/tz/2018-November/027194.html
Rule Zion 1980 only - Aug 2 0:00 1:00 D
Rule Zion 1980 only - Sep 13 1:00 0 S
Rule Zion 1984 only - May 5 0:00 1:00 D
Rule Zion 1984 only - Aug 25 1:00 0 S
# From Shanks & Pottenger:
Rule Zion 1985 only - Apr 14 0:00 1:00 D
Rule Zion 1985 only - Sep 15 0:00 0 S
Rule Zion 1986 only - May 18 0:00 1:00 D
Rule Zion 1986 only - Sep 7 0:00 0 S
Rule Zion 1987 only - Apr 15 0:00 1:00 D
Rule Zion 1987 only - Sep 13 0:00 0 S
# From Avigdor Finkelstein (2014-03-05):
# I check the Parliament (Knesset) records and there it's stated that the
# [1988] transition should take place on Saturday night, when the Sabbath
# ends and changes to Sunday.
Rule Zion 1988 only - Apr 10 0:00 1:00 D
Rule Zion 1988 only - Sep 4 0:00 0 S
# From Ephraim Silverberg
# (1997-03-04, 1998-03-16, 1998-12-28, 2000-01-17, 2000-07-25, 2004-12-22,
# and 2005-02-17):
# According to the Office of the Secretary General of the Ministry of
# Interior, there is NO set rule for Daylight-Savings/Standard time changes.
# One thing is entrenched in law, however: that there must be at least 150
# days of daylight savings time annually. From 1993-1998, the change to
# daylight savings time was on a Friday morning from midnight IST to
# 1 a.m IDT; up until 1998, the change back to standard time was on a
# Saturday night from midnight daylight savings time to 11 p.m. standard
# time. 1996 is an exception to this rule where the change back to standard
# time took place on Sunday night instead of Saturday night to avoid
# conflicts with the Jewish New Year. In 1999, the change to
# daylight savings time was still on a Friday morning but from
# 2 a.m. IST to 3 a.m. IDT; furthermore, the change back to standard time
# was also on a Friday morning from 2 a.m. IDT to 1 a.m. IST for
# 1999 only. In the year 2000, the change to daylight savings time was
# similar to 1999, but although the change back will be on a Friday, it
# will take place from 1 a.m. IDT to midnight IST. Starting in 2001, all
# changes to/from will take place at 1 a.m. old time, but now there is no
# rule as to what day of the week it will take place in as the start date
# (except in 2003) is the night after the Passover Seder (i.e. the eve
# of the 16th of Nisan in the lunar Hebrew calendar) and the end date
# (except in 2002) is three nights before Yom Kippur [Day of Atonement]
# (the eve of the 7th of Tishrei in the lunar Hebrew calendar).
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Zion 1989 only - Apr 30 0:00 1:00 D
Rule Zion 1989 only - Sep 3 0:00 0 S
Rule Zion 1990 only - Mar 25 0:00 1:00 D
Rule Zion 1990 only - Aug 26 0:00 0 S
Rule Zion 1991 only - Mar 24 0:00 1:00 D
Rule Zion 1991 only - Sep 1 0:00 0 S
Rule Zion 1992 only - Mar 29 0:00 1:00 D
Rule Zion 1992 only - Sep 6 0:00 0 S
Rule Zion 1993 only - Apr 2 0:00 1:00 D
Rule Zion 1993 only - Sep 5 0:00 0 S
# The dates for 1994-1995 were obtained from Office of the Spokeswoman for the
# Ministry of Interior, Jerusalem, Israel. The spokeswoman can be reached by
# calling the office directly at 972-2-6701447 or 972-2-6701448.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Zion 1994 only - Apr 1 0:00 1:00 D
Rule Zion 1994 only - Aug 28 0:00 0 S
Rule Zion 1995 only - Mar 31 0:00 1:00 D
Rule Zion 1995 only - Sep 3 0:00 0 S
# The dates for 1996 were determined by the Minister of Interior of the
# time, Haim Ramon. The official announcement regarding 1996-1998
# (with the dates for 1997-1998 no longer being relevant) can be viewed at:
#
# ftp://ftp.cs.huji.ac.il/pub/tz/announcements/1996-1998.ramon.ps.gz
#
# The dates for 1997-1998 were altered by his successor, Rabbi Eli Suissa.
#
# The official announcements for the years 1997-1999 can be viewed at:
#
# ftp://ftp.cs.huji.ac.il/pub/tz/announcements/YYYY.ps.gz
#
# where YYYY is the relevant year.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Zion 1996 only - Mar 15 0:00 1:00 D
Rule Zion 1996 only - Sep 16 0:00 0 S
Rule Zion 1997 only - Mar 21 0:00 1:00 D
Rule Zion 1997 only - Sep 14 0:00 0 S
Rule Zion 1998 only - Mar 20 0:00 1:00 D
Rule Zion 1998 only - Sep 6 0:00 0 S
Rule Zion 1999 only - Apr 2 2:00 1:00 D
Rule Zion 1999 only - Sep 3 2:00 0 S
# The Knesset Interior Committee has changed the dates for 2000 for
# the third time in just over a year and have set new dates for the
# years 2001-2004 as well.
#
# The official announcement for the start date of 2000 can be viewed at:
#
# ftp://ftp.cs.huji.ac.il/pub/tz/announcements/2000-start.ps.gz
#
# The official announcement for the end date of 2000 and the dates
# for the years 2001-2004 can be viewed at:
#
# ftp://ftp.cs.huji.ac.il/pub/tz/announcements/2000-2004.ps.gz
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Zion 2000 only - Apr 14 2:00 1:00 D
Rule Zion 2000 only - Oct 6 1:00 0 S
Rule Zion 2001 only - Apr 9 1:00 1:00 D
Rule Zion 2001 only - Sep 24 1:00 0 S
Rule Zion 2002 only - Mar 29 1:00 1:00 D
Rule Zion 2002 only - Oct 7 1:00 0 S
Rule Zion 2003 only - Mar 28 1:00 1:00 D
Rule Zion 2003 only - Oct 3 1:00 0 S
Rule Zion 2004 only - Apr 7 1:00 1:00 D
Rule Zion 2004 only - Sep 22 1:00 0 S
# The proposed law agreed upon by the Knesset Interior Committee on
# 2005-02-14 is that, for 2005 and beyond, DST starts at 02:00 the
# last Friday before April 2nd (i.e. the last Friday in March or April
# 1st itself if it falls on a Friday) and ends at 02:00 on the Saturday
# night _before_ the fast of Yom Kippur.
#
# Those who can read Hebrew can view the announcement at:
#
# ftp://ftp.cs.huji.ac.il/pub/tz/announcements/2005+beyond.ps
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Zion 2005 2012 - Apr Fri<=1 2:00 1:00 D
Rule Zion 2005 only - Oct 9 2:00 0 S
Rule Zion 2006 only - Oct 1 2:00 0 S
Rule Zion 2007 only - Sep 16 2:00 0 S
Rule Zion 2008 only - Oct 5 2:00 0 S
Rule Zion 2009 only - Sep 27 2:00 0 S
Rule Zion 2010 only - Sep 12 2:00 0 S
Rule Zion 2011 only - Oct 2 2:00 0 S
Rule Zion 2012 only - Sep 23 2:00 0 S
# From Ephraim Silverberg (2013-06-27):
# On June 23, 2013, the Israeli government approved changes to the
# Time Decree Law. The next day, the changes passed the First Reading
# in the Knesset. The law is expected to pass the Second and Third
# (final) Readings by the beginning of September 2013.
#
# As of 2013, DST starts at 02:00 on the Friday before the last Sunday
# in March. DST ends at 02:00 on the last Sunday of October.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Zion 2013 max - Mar Fri>=23 2:00 1:00 D
Rule Zion 2013 max - Oct lastSun 2:00 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Jerusalem 2:20:54 - LMT 1880
2:20:40 - JMT 1918 # Jerusalem Mean Time?
2:00 Zion I%sT
###############################################################################
# Japan
# '9:00' and 'JST' is from Guy Harris.
# From Paul Eggert (1995-03-06):
# Today's _Asahi Evening News_ (page 4) reports that Japan had
# daylight saving between 1948 and 1951, but "the system was discontinued
# because the public believed it would lead to longer working hours."
# From Mayumi Negishi in the 2005-08-10 Japan Times:
# http://www.japantimes.co.jp/cgi-bin/getarticle.pl5?nn20050810f2.htm
# Occupation authorities imposed daylight-saving time on Japan on
# [1948-05-01].... But lack of prior debate and the execution of
# daylight-saving time just three days after the bill was passed generated
# deep hatred of the concept.... The Diet unceremoniously passed a bill to
# dump the unpopular system in October 1951, less than a month after the San
# Francisco Peace Treaty was signed. (A government poll in 1951 showed 53%
# of the Japanese wanted to scrap daylight-saving time, as opposed to 30% who
# wanted to keep it.)
# From Takayuki Nikai (2018-01-19):
# The source of information is Japanese law.
# http://www.shugiin.go.jp/internet/itdb_housei.nsf/html/houritsu/00219480428029.htm
# http://www.shugiin.go.jp/internet/itdb_housei.nsf/html/houritsu/00719500331039.htm
# ... In summary, it is written as follows. From 24:00 on the first Saturday
# in May, until 0:00 on the day after the second Saturday in September.
# From Phake Nick (2018-09-27):
# [T]he webpage authored by National Astronomical Observatory of Japan
# https://eco.mtk.nao.ac.jp/koyomi/wiki/BBFEB9EF2FB2C6BBFEB9EF.html
# ... mentioned that using Showa 23 (year 1948) as example, 13pm of September
# 11 in summer time will equal to 0am of September 12 in standard time.
# It cited a document issued by the Liaison Office which briefly existed
# during the postwar period of Japan, where the detail on implementation
# of the summer time is described in the document.
# https://eco.mtk.nao.ac.jp/koyomi/wiki/BBFEB9EF2FB2C6BBFEB9EFB2C6BBFEB9EFA4CEBCC2BBDCA4CBA4C4A4A4A4C6.pdf
# The text in the document do instruct a fall back to occur at
# September 11, 13pm in summer time, while ordinary citizens can
# change the clock before they sleep.
#
# From Paul Eggert (2018-09-27):
# This instruction is equivalent to "Sat>=8 25:00", so use that. zic treats
# it like "Sun>=9 01:00", which is not quite the same but is the best we can
# do in any POSIX or C platform. The "25:00" assumes zic from 2007 or later,
# which should be safe now.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Japan 1948 only - May Sat>=1 24:00 1:00 D
Rule Japan 1948 1951 - Sep Sat>=8 25:00 0 S
Rule Japan 1949 only - Apr Sat>=1 24:00 1:00 D
Rule Japan 1950 1951 - May Sat>=1 24:00 1:00 D
# From Hideyuki Suzuki (1998-11-09):
# 'Tokyo' usually stands for the former location of Tokyo Astronomical
# Observatory: 139° 44' 40.90" E (9h 18m 58.727s), 35° 39' 16.0" N.
# This data is from 'Rika Nenpyou (Chronological Scientific Tables) 1996'
# edited by National Astronomical Observatory of Japan....
# JST (Japan Standard Time) has been used since 1888-01-01 00:00 (JST).
# The law is enacted on 1886-07-07.
# From Hideyuki Suzuki (1998-11-16):
# The ordinance No. 51 (1886) established "standard time" in Japan,
# which stands for the time on 135° E.
# In the ordinance No. 167 (1895), "standard time" was renamed to "central
# standard time". And the same ordinance also established "western standard
# time", which stands for the time on 120° E.... But "western standard
# time" was abolished in the ordinance No. 529 (1937). In the ordinance No.
# 167, there is no mention regarding for what place western standard time is
# standard....
#
# I wrote "ordinance" above, but I don't know how to translate.
# In Japanese it's "chokurei", which means ordinance from emperor.
# From Yu-Cheng Chuang (2013-07-12):
# ...the Meiji Emperor announced Ordinance No. 167 of Meiji Year 28 "The clause
# about standard time" ... The adoption began from Jan 1, 1896.
# https://ja.wikisource.org/wiki/標準時ニ關スル件_(公布時)
#
# ...the Showa Emperor announced Ordinance No. 529 of Showa Year 12 ... which
# means the whole Japan territory, including later occupations, adopt Japan
# Central Time (UT+9). The adoption began on Oct 1, 1937.
# https://ja.wikisource.org/wiki/明治二十八年勅令第百六十七號標準時ニ關スル件中改正ノ件
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Tokyo 9:18:59 - LMT 1887 Dec 31 15:00u
9:00 Japan J%sT
# Since 1938, all Japanese possessions have been like Asia/Tokyo,
# except that Truk (Chuuk), Ponape (Pohnpei), and Jaluit (Kosrae) did not
# switch from +10 to +09 until 1941-04-01; see the 'australasia' file.
# Jordan
#
# From <http://star.arabia.com/990701/JO9.html>
# Jordan Week (1999-07-01) via Steffen Thorsen (1999-09-09):
# Clocks in Jordan were forwarded one hour on Wednesday at midnight,
# in accordance with the government's decision to implement summer time
# all year round.
#
# From <http://star.arabia.com/990930/JO9.html>
# Jordan Week (1999-09-30) via Steffen Thorsen (1999-11-09):
# Winter time starts today Thursday, 30 September. Clocks will be turned back
# by one hour. This is the latest government decision and it's final!
# The decision was taken because of the increase in working hours in
# government's departments from six to seven hours.
#
# From Paul Eggert (2005-11-22):
# Starting 2003 transitions are from Steffen Thorsen's web site timeanddate.com.
#
# From Steffen Thorsen (2005-11-23):
# For Jordan I have received multiple independent user reports every year
# about DST end dates, as the end-rule is different every year.
#
# From Steffen Thorsen (2006-10-01), after a heads-up from Hilal Malawi:
# http://www.petranews.gov.jo/nepras/2006/Sep/05/4000.htm
# "Jordan will switch to winter time on Friday, October 27".
#
# From Steffen Thorsen (2009-04-02):
# This single one might be good enough, (2009-03-24, Arabic):
# http://petra.gov.jo/Artical.aspx?Lng=2&Section=8&Artical=95279
#
# Google's translation:
#
# > The Council of Ministers decided in 2002 to adopt the principle of timely
# > submission of the summer at 60 minutes as of midnight on the last Thursday
# > of the month of March of each year.
#
# So - this means the midnight between Thursday and Friday since 2002.
# From Arthur David Olson (2009-04-06):
# We still have Jordan switching to DST on Thursdays in 2000 and 2001.
# From Steffen Thorsen (2012-10-25):
# Yesterday the government in Jordan announced that they will not
# switch back to standard time this winter, so the will stay on DST
# until about the same time next year (at least).
# http://www.petra.gov.jo/Public_News/Nws_NewsDetails.aspx?NewsID=88950
# From Steffen Thorsen (2013-12-11):
# Jordan Times and other sources say that Jordan is going back to
# UTC+2 on 2013-12-19 at midnight:
# http://jordantimes.com/govt-decides-to-switch-back-to-wintertime
# Official, in Arabic:
# http://www.petra.gov.jo/public_news/Nws_NewsDetails.aspx?Menu_ID=&Site_Id=2&lang=1&NewsID=133230&CatID=14
# ... Our background/permalink about it
# https://www.timeanddate.com/news/time/jordan-reverses-dst-decision.html
# ...
# http://www.petra.gov.jo/Public_News/Nws_NewsDetails.aspx?lang=2&site_id=1&NewsID=133313&Type=P
# ... says midnight for the coming one and 1:00 for the ones in the future
# (and they will use DST again next year, using the normal schedule).
# From Paul Eggert (2013-12-11):
# As Steffen suggested, consider the past 21-month experiment to be DST.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Jordan 1973 only - Jun 6 0:00 1:00 S
Rule Jordan 1973 1975 - Oct 1 0:00 0 -
Rule Jordan 1974 1977 - May 1 0:00 1:00 S
Rule Jordan 1976 only - Nov 1 0:00 0 -
Rule Jordan 1977 only - Oct 1 0:00 0 -
Rule Jordan 1978 only - Apr 30 0:00 1:00 S
Rule Jordan 1978 only - Sep 30 0:00 0 -
Rule Jordan 1985 only - Apr 1 0:00 1:00 S
Rule Jordan 1985 only - Oct 1 0:00 0 -
Rule Jordan 1986 1988 - Apr Fri>=1 0:00 1:00 S
Rule Jordan 1986 1990 - Oct Fri>=1 0:00 0 -
Rule Jordan 1989 only - May 8 0:00 1:00 S
Rule Jordan 1990 only - Apr 27 0:00 1:00 S
Rule Jordan 1991 only - Apr 17 0:00 1:00 S
Rule Jordan 1991 only - Sep 27 0:00 0 -
Rule Jordan 1992 only - Apr 10 0:00 1:00 S
Rule Jordan 1992 1993 - Oct Fri>=1 0:00 0 -
Rule Jordan 1993 1998 - Apr Fri>=1 0:00 1:00 S
Rule Jordan 1994 only - Sep Fri>=15 0:00 0 -
Rule Jordan 1995 1998 - Sep Fri>=15 0:00s 0 -
Rule Jordan 1999 only - Jul 1 0:00s 1:00 S
Rule Jordan 1999 2002 - Sep lastFri 0:00s 0 -
Rule Jordan 2000 2001 - Mar lastThu 0:00s 1:00 S
Rule Jordan 2002 2012 - Mar lastThu 24:00 1:00 S
Rule Jordan 2003 only - Oct 24 0:00s 0 -
Rule Jordan 2004 only - Oct 15 0:00s 0 -
Rule Jordan 2005 only - Sep lastFri 0:00s 0 -
Rule Jordan 2006 2011 - Oct lastFri 0:00s 0 -
Rule Jordan 2013 only - Dec 20 0:00 0 -
Rule Jordan 2014 max - Mar lastThu 24:00 1:00 S
Rule Jordan 2014 max - Oct lastFri 0:00s 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Amman 2:23:44 - LMT 1931
2:00 Jordan EE%sT
# Kazakhstan
# From Kazakhstan Embassy's News Bulletin No. 11
# <http://www.kazsociety.org.uk/news/2005/03/30.htm> (2005-03-21):
# The Government of Kazakhstan passed a resolution March 15 abolishing
# daylight saving time citing lack of economic benefits and health
# complications coupled with a decrease in productivity.
#
# From Branislav Kojic (in Astana) via Gwillim Law (2005-06-28):
# ... what happened was that the former Kazakhstan Eastern time zone
# was "blended" with the Central zone. Therefore, Kazakhstan now has
# two time zones, and difference between them is one hour. The zone
# closer to UTC is the former Western zone (probably still called the
# same), encompassing four provinces in the west: Aqtöbe, Atyraū,
# Mangghystaū, and West Kazakhstan. The other zone encompasses
# everything else.... I guess that would make Kazakhstan time zones
# de jure UTC+5 and UTC+6 respectively.
# From Stepan Golosunov (2016-03-27):
# Review of the linked documents from http://adilet.zan.kz/
# produced the following data for post-1991 Kazakhstan:
#
# 0. Act of the Cabinet of Ministers of the USSR
# from 1991-02-04 No. 20
# http://pravo.gov.ru/proxy/ips/?docbody=&nd=102010545
# removed the extra hour ("decree time") on the territory of the USSR
# starting with the last Sunday of March 1991.
# It also allowed (but not mandated) Kazakh SSR, Kirghiz SSR, Tajik SSR,
# Turkmen SSR and Uzbek SSR to not have "summer" time.
#
# The 1992-01-13 act also refers to the act of the Cabinet of Ministers
# of the Kazakh SSR from 1991-03-20 No. 170 "About the act of the Cabinet
# of Ministers of the USSR from 1991-02-04 No. 20" but I didn't found its
# text.
#
# According to Izvestia newspaper No. 68 (23334) from 1991-03-20
# -- page 6; available at http://libinfo.org/newsr/newsr2574.djvu via
# http://libinfo.org/index.php?id=58564 -- on 1991-03-31 at 2:00 during
# transition to "summer" time:
# Republic of Georgia, Latvian SSR, Lithuanian SSR, SSR Moldova,
# Estonian SSR; Komi ASSR; Kaliningrad oblast; Nenets autonomous okrug
# were to move clocks 1 hour forward.
# Kazakh SSR (excluding Uralsk oblast); Republic of Kyrgyzstan, Tajik
# SSR; Andijan, Jizzakh, Namangan, Sirdarya, Tashkent, Fergana oblasts
# of the Uzbek SSR were to move clocks 1 hour backwards.
# Other territories were to not move clocks.
# When the "summer" time would end on 1991-09-29, clocks were to be
# moved 1 hour backwards on the territory of the USSR excluding
# Kazakhstan, Kirghizia, Uzbekistan, Turkmenia, Tajikistan.
#
# Apparently there were last minute changes. Apparently Kazakh act No. 170
# was one of such changes.
#
# https://ru.wikipedia.org/wiki/Декретное_время
# claims that Sovetskaya Rossiya newspaper on 1991-03-29 published that
# Nenets autonomous okrug, Komi and Kazakhstan (excluding Uralsk oblast)
# were to not move clocks and Uralsk oblast was to move clocks
# forward; on 1991-09-29 Kazakhstan was to move clocks backwards.
# (Probably there were changes even after that publication. There is an
# article claiming that Kaliningrad oblast decided on 1991-03-29 to not
# move clocks.)
#
# This implies that on 1991-03-31 Asia/Oral remained on +04/+05 while
# the rest of Kazakhstan switched from +06/+07 to +05/06 or from +05/06
# to +04/+05. It's unclear how Qyzylorda oblast moved into the fifth
# time belt. (By switching from +04/+05 to +05/+06 on 1991-09-29?) ...
#
# 1. Act of the Cabinet of Ministers of the Republic of Kazakhstan
# from 1992-01-13 No. 28
# http://adilet.zan.kz/rus/docs/P920000028_
# (text includes modification from the 1996 act)
# introduced new rules for calculation of time, mirroring Russian
# 1992-01-08 act. It specified that time would be calculated
# according to time belts plus extra hour ("decree time"), moved clocks
# on the whole territory of Kazakhstan 1 hour forward on 1992-01-19 at
# 2:00, specified DST rules. It acknowledged that Kazakhstan was
# located in the fourth and the fifth time belts and specified the
# border between them to be located east of Qostanay and Aktyubinsk
# oblasts (notably including Turgai and Qyzylorda oblasts into the fifth
# time belt).
#
# This means switch on 1992-01-19 at 2:00 from +04/+05 to +05/+06 for
# Asia/Aqtau, Asia/Aqtobe, Asia/Oral, Atyraū and Qostanay oblasts; from
# +05/+06 to +06/+07 for Asia/Almaty and Asia/Qyzylorda (and Arkalyk)....
#
# 2. Act of the Cabinet of Ministers of the Republic of Kazakhstan
# from 1992-03-27 No. 284
# http://adilet.zan.kz/rus/docs/P920000284_
# cancels extra hour ("decree time") for Uralsk and Qyzylorda oblasts
# since the last Sunday of March 1992, while keeping them in the fourth
# and the fifth time belts respectively.
#
# 3. Order of the Prime Minister of the Republic of Kazakhstan
# from 1994-09-23 No. 384
# http://adilet.zan.kz/rus/docs/R940000384_
# cancels the extra hour ("decree time") on the territory of Mangghystaū
# oblast since the last Sunday of September 1994 (saying that time on
# the territory would correspond to the third time belt as a
# result)....
#
# 4. Act of the Government of the Republic of Kazakhstan
# from 1996-05-08 No. 575
# http://adilet.zan.kz/rus/docs/P960000575_
# amends the 1992-01-13 act to end summer time in October instead
# of September, mirroring identical Russian change from 1996-04-23 act.
#
# 5. Act of the Government of the Republic of Kazakhstan
# from 1999-03-26 No. 305
# http://adilet.zan.kz/rus/docs/P990000305_
# cancels the extra hour ("decree time") for Atyraū oblast since the
# last Sunday of March 1999 while retaining the oblast in the fourth
# time belt.
#
# This means change from +05/+06 to +04/+05....
#
# 6. Act of the Government of the Republic of Kazakhstan
# from 2000-11-23 No. 1749
# http://adilet.zan.kz/rus/archive/docs/P000001749_/23.11.2000
# replaces the previous five documents.
#
# The only changes I noticed are in definition of the border between the
# fourth and the fifth time belts. They account for changes in spelling
# and administrative division (splitting of Turgai oblast in 1997
# probably changed time in territories incorporated into Qostanay oblast
# (including Arkalyk) from +06/+07 to +05/+06) and move Qyzylorda oblast
# from being in the fifth time belt and not using decree time into the
# fourth time belt (no change in practice).
#
# 7. Act of the Government of the Republic of Kazakhstan
# from 2003-12-29 No. 1342
# http://adilet.zan.kz/rus/docs/P030001342_
# modified the 2000-11-23 act. No relevant changes, apparently.
#
# 8. Act of the Government of the Republic of Kazakhstan
# from 2004-07-20 No. 775
# http://adilet.zan.kz/rus/archive/docs/P040000775_/20.07.2004
# modified the 2000-11-23 act to move Qostanay and Qyzylorda oblasts into
# the fifth time belt and add Aktobe oblast to the list of regions not
# using extra hour ("decree time"), leaving Kazakhstan with only 2 time
# zones (+04/+05 and +06/+07). The changes were to be implemented
# during DST transitions in 2004 and 2005 but the acts got radically
# amended before implementation happened.
#
# 9. Act of the Government of the Republic of Kazakhstan
# from 2004-09-15 No. 1059
# http://adilet.zan.kz/rus/docs/P040001059_
# modified the 2000-11-23 act to remove exceptions from the "decree time"
# (leaving Kazakhstan in +05/+06 and +06/+07 zones), amended the
# 2004-07-20 act to implement changes for Atyraū, West Kazakhstan,
# Qostanay, Qyzylorda and Mangghystaū oblasts by not moving clocks
# during the 2004 transition to "winter" time.
#
# This means transition from +04/+05 to +05/+06 for Atyraū oblast (no
# zone currently), Asia/Oral, Asia/Aqtau and transition from +05/+06 to
# +06/+07 for Qostanay oblast (Qostanay and Arkalyk, no zones currently)
# and Asia/Qyzylorda on 2004-10-31 at 3:00....
#
# 10. Act of the Government of the Republic of Kazakhstan
# from 2005-03-15 No. 231
# http://adilet.zan.kz/rus/docs/P050000231_
# removes DST provisions from the 2000-11-23 act, removes most of the
# (already implemented) provisions from the 2004-07-20 and 2004-09-15
# acts, comes into effect 10 days after official publication.
# The only practical effect seems to be the abolition of the summer
# time.
#
# Unamended version of the act of the Government of the Russian Federation
# No. 23 from 1992-01-08 [See 'europe' file for details].
# Kazakh 1992-01-13 act appears to provide the same rules and 1992-03-27
# act was to be enacted on the last Sunday of March 1992.
# From Stepan Golosunov (2016-11-08):
# Turgai reorganization should affect only southern part of Qostanay
# oblast. Which should probably be separated into Asia/Arkalyk zone.
# (There were also 1970, 1988 and 1990 Turgai oblast reorganizations
# according to wikipedia.)
#
# [For Qostanay] http://www.ng.kz/gazeta/195/hranit/
# suggests that clocks were to be moved 40 minutes backwards on
# 1920-01-01 to the fourth time belt. But I do not understand
# how that could happen....
#
# [For Atyrau and Oral] 1919 decree
# (http://www.worldtimezone.com/dst_news/dst_news_russia-1919-02-08.html
# and in Byalokoz) lists Ural river (plus 10 versts on its left bank) in
# the third time belt (before 1930 this means +03).
# From Alexander Konzurovski (2018-12-20):
# Qyzyolrda Region (Asia/Qyzylorda) is changing its time zone from
# UTC+6 to UTC+5 effective December 21st, 2018. The legal document is
# located here: http://adilet.zan.kz/rus/docs/P1800000817 (russian language).
# Zone NAME STDOFF RULES FORMAT [UNTIL]
#
# Almaty (formerly Alma-Ata), representing most locations in Kazakhstan
# This includes KZ-AKM, KZ-ALA, KZ-ALM, KZ-AST, KZ-BAY, KZ-VOS, KZ-ZHA,
# KZ-KAR, KZ-SEV, KZ-PAV, and KZ-YUZ.
Zone Asia/Almaty 5:07:48 - LMT 1924 May 2 # or Alma-Ata
5:00 - +05 1930 Jun 21
6:00 RussiaAsia +06/+07 1991 Mar 31 2:00s
5:00 RussiaAsia +05/+06 1992 Jan 19 2:00s
6:00 RussiaAsia +06/+07 2004 Oct 31 2:00s
6:00 - +06
# Qyzylorda (aka Kyzylorda, Kizilorda, Kzyl-Orda, etc.) (KZ-KZY)
Zone Asia/Qyzylorda 4:21:52 - LMT 1924 May 2
4:00 - +04 1930 Jun 21
5:00 - +05 1981 Apr 1
5:00 1:00 +06 1981 Oct 1
6:00 - +06 1982 Apr 1
5:00 RussiaAsia +05/+06 1991 Mar 31 2:00s
4:00 RussiaAsia +04/+05 1991 Sep 29 2:00s
5:00 RussiaAsia +05/+06 1992 Jan 19 2:00s
6:00 RussiaAsia +06/+07 1992 Mar 29 2:00s
5:00 RussiaAsia +05/+06 2004 Oct 31 2:00s
6:00 - +06 2018 Dec 21 0:00
5:00 - +05
#
# Qostanay (aka Kostanay, Kustanay) (KZ-KUS)
# The 1991/2 rules are unclear partly because of the 1997 Turgai
# reorganization.
Zone Asia/Qostanay 4:14:28 - LMT 1924 May 2
4:00 - +04 1930 Jun 21
5:00 - +05 1981 Apr 1
5:00 1:00 +06 1981 Oct 1
6:00 - +06 1982 Apr 1
5:00 RussiaAsia +05/+06 1991 Mar 31 2:00s
4:00 RussiaAsia +04/+05 1992 Jan 19 2:00s
5:00 RussiaAsia +05/+06 2004 Oct 31 2:00s
6:00 - +06
# Aqtöbe (aka Aktobe, formerly Aktyubinsk) (KZ-AKT)
Zone Asia/Aqtobe 3:48:40 - LMT 1924 May 2
4:00 - +04 1930 Jun 21
5:00 - +05 1981 Apr 1
5:00 1:00 +06 1981 Oct 1
6:00 - +06 1982 Apr 1
5:00 RussiaAsia +05/+06 1991 Mar 31 2:00s
4:00 RussiaAsia +04/+05 1992 Jan 19 2:00s
5:00 RussiaAsia +05/+06 2004 Oct 31 2:00s
5:00 - +05
# Mangghystaū (KZ-MAN)
# Aqtau was not founded until 1963, but it represents an inhabited region,
# so include timestamps before 1963.
Zone Asia/Aqtau 3:21:04 - LMT 1924 May 2
4:00 - +04 1930 Jun 21
5:00 - +05 1981 Oct 1
6:00 - +06 1982 Apr 1
5:00 RussiaAsia +05/+06 1991 Mar 31 2:00s
4:00 RussiaAsia +04/+05 1992 Jan 19 2:00s
5:00 RussiaAsia +05/+06 1994 Sep 25 2:00s
4:00 RussiaAsia +04/+05 2004 Oct 31 2:00s
5:00 - +05
# Atyraū (KZ-ATY) is like Mangghystaū except it switched from
# +04/+05 to +05/+06 in spring 1999, not fall 1994.
Zone Asia/Atyrau 3:27:44 - LMT 1924 May 2
3:00 - +03 1930 Jun 21
5:00 - +05 1981 Oct 1
6:00 - +06 1982 Apr 1
5:00 RussiaAsia +05/+06 1991 Mar 31 2:00s
4:00 RussiaAsia +04/+05 1992 Jan 19 2:00s
5:00 RussiaAsia +05/+06 1999 Mar 28 2:00s
4:00 RussiaAsia +04/+05 2004 Oct 31 2:00s
5:00 - +05
# West Kazakhstan (KZ-ZAP)
# From Paul Eggert (2016-03-18):
# The 1989 transition is from USSR act No. 227 (1989-03-14).
Zone Asia/Oral 3:25:24 - LMT 1924 May 2 # or Ural'sk
3:00 - +03 1930 Jun 21
5:00 - +05 1981 Apr 1
5:00 1:00 +06 1981 Oct 1
6:00 - +06 1982 Apr 1
5:00 RussiaAsia +05/+06 1989 Mar 26 2:00s
4:00 RussiaAsia +04/+05 1992 Jan 19 2:00s
5:00 RussiaAsia +05/+06 1992 Mar 29 2:00s
4:00 RussiaAsia +04/+05 2004 Oct 31 2:00s
5:00 - +05
# Kyrgyzstan (Kirgizstan)
# Transitions through 1991 are from Shanks & Pottenger.
# From Paul Eggert (2005-08-15):
# According to an article dated today in the Kyrgyzstan Development Gateway
# http://eng.gateway.kg/cgi-bin/page.pl?id=1&story_name=doc9979.shtml
# Kyrgyzstan is canceling the daylight saving time system. I take the article
# to mean that they will leave their clocks at 6 hours ahead of UTC.
# From Malik Abdugaliev (2005-09-21):
# Our government cancels daylight saving time 6th of August 2005.
# From 2005-08-12 our GMT-offset is +6, w/o any daylight saving.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Kyrgyz 1992 1996 - Apr Sun>=7 0:00s 1:00 -
Rule Kyrgyz 1992 1996 - Sep lastSun 0:00 0 -
Rule Kyrgyz 1997 2005 - Mar lastSun 2:30 1:00 -
Rule Kyrgyz 1997 2004 - Oct lastSun 2:30 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Bishkek 4:58:24 - LMT 1924 May 2
5:00 - +05 1930 Jun 21
6:00 RussiaAsia +06/+07 1991 Mar 31 2:00s
5:00 RussiaAsia +05/+06 1991 Aug 31 2:00
5:00 Kyrgyz +05/+06 2005 Aug 12
6:00 - +06
###############################################################################
# Korea (North and South)
# From Annie I. Bang (2006-07-10):
# http://www.koreaherald.com/view.php?ud=200607100012
# Korea ran a daylight saving program from 1949-61 but stopped it
# during the 1950-53 Korean War. The system was temporarily enforced
# between 1987 and 1988 ...
# From Sanghyuk Jung (2014-10-29):
# https://mm.icann.org/pipermail/tz/2014-October/021830.html
# According to the Korean Wikipedia
# https://ko.wikipedia.org/wiki/한국_표준시
# [oldid=12896437 2014-09-04 08:03 UTC]
# DST in Republic of Korea was as follows.... And I checked old
# newspapers in Korean, all articles correspond with data in Wikipedia.
# For example, the article in 1948 (Korean Language) proved that DST
# started at June 1 in that year. For another example, the article in
# 1988 said that DST started at 2:00 AM in that year.
# From Phake Nick (2018-10-27):
# 1. According to official announcement from Korean government, the DST end
# date in South Korea should be
# 1955-09-08 without specifying time
# http://theme.archives.go.kr/next/common/viewEbook.do?singleData=N&archiveEventId=0027977557
# 1956-09-29 without specifying time
# http://theme.archives.go.kr/next/common/viewEbook.do?singleData=N&archiveEventId=0027978341
# 1957-09-21 24 o'clock
# http://theme.archives.go.kr/next/common/viewEbook.do?singleData=N&archiveEventId=0027979690#3
# 1958-09-20 24 o'clock
# http://theme.archives.go.kr/next/common/viewEbook.do?singleData=N&archiveEventId=0027981189
# 1959-09-19 24 o'clock
# http://theme.archives.go.kr/next/common/viewEbook.do?singleData=N&archiveEventId=0027982974#2
# 1960-09-17 24 o'clock
# http://theme.archives.go.kr/next/common/viewEbook.do?singleData=N&archiveEventId=0028044104
# ...
# 2.... https://namu.wiki/w/대한민국%20표준시 ... [says]
# when Korea was using GMT+8:30 as standard time, the international
# aviation/marine/meteorological industry in the country refused to
# follow and continued to use GMT+9:00 for interoperability.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule ROK 1948 only - Jun 1 0:00 1:00 D
Rule ROK 1948 only - Sep 12 24:00 0 S
Rule ROK 1949 only - Apr 3 0:00 1:00 D
Rule ROK 1949 1951 - Sep Sat>=7 24:00 0 S
Rule ROK 1950 only - Apr 1 0:00 1:00 D
Rule ROK 1951 only - May 6 0:00 1:00 D
Rule ROK 1955 only - May 5 0:00 1:00 D
Rule ROK 1955 only - Sep 8 24:00 0 S
Rule ROK 1956 only - May 20 0:00 1:00 D
Rule ROK 1956 only - Sep 29 24:00 0 S
Rule ROK 1957 1960 - May Sun>=1 0:00 1:00 D
Rule ROK 1957 1960 - Sep Sat>=17 24:00 0 S
Rule ROK 1987 1988 - May Sun>=8 2:00 1:00 D
Rule ROK 1987 1988 - Oct Sun>=8 3:00 0 S
# From Paul Eggert (2016-08-23):
# The Korean Wikipedia entry gives the following sources for UT offsets:
#
# 1908: Official Journal Article No. 3994 (decree No. 5)
# 1912: Governor-General of Korea Official Gazette Issue No. 367
# (Announcement No. 338)
# 1954: Presidential Decree No. 876 (1954-03-17)
# 1961: Law No. 676 (1961-08-07)
#
# (Another source "1987: Law No. 3919 (1986-12-31)" was in the 2014-10-30
# edition of the Korean Wikipedia entry.)
#
# I guessed that time zone abbreviations through 1945 followed the same
# rules as discussed under Taiwan, with nominal switches from JST to KST
# when the respective cities were taken over by the Allies after WWII.
#
# For Pyongyang, guess no changes from World War II until 2015, as we
# have no information otherwise.
# From Steffen Thorsen (2015-08-07):
# According to many news sources, North Korea is going to change to
# the 8:30 time zone on August 15, one example:
# http://www.bbc.com/news/world-asia-33815049
#
# From Paul Eggert (2015-08-15):
# Bells rang out midnight (00:00) Friday as part of the celebrations. See:
# Talmadge E. North Korea celebrates new time zone, 'Pyongyang Time'
# http://news.yahoo.com/north-korea-celebrates-time-zone-pyongyang-time-164038128.html
# There is no common English-language abbreviation for this time zone.
# Use KST, as that's what we already use for 1954-1961 in ROK.
# From Kang Seonghoon (2018-04-29):
# North Korea will revert its time zone from UTC+8:30 (PYT; Pyongyang
# Time) back to UTC+9 (KST; Korea Standard Time).
#
# From Seo Sanghyeon (2018-04-30):
# Rodong Sinmun 2018-04-30 announced Pyongyang Time transition plan.
# https://www.nknews.org/kcna/wp-content/uploads/sites/5/2018/04/rodong-2018-04-30.pdf
# ... the transition date is 2018-05-05 ... Citation should be Decree
# No. 2232 of April 30, 2018, of the Presidium of the Supreme People's
# Assembly, as published in Rodong Sinmun.
# From Tim Parenti (2018-04-29):
# It appears to be the front page story at the top in the right-most column.
#
# From Paul Eggert (2018-05-04):
# The BBC reported that the transition was from 23:30 to 24:00 today.
# https://www.bbc.com/news/world-asia-44010705
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Seoul 8:27:52 - LMT 1908 Apr 1
8:30 - KST 1912 Jan 1
9:00 - JST 1945 Sep 8
- 9:00 - KST 1954 Mar 21
+ 9:00 ROK K%sT 1954 Mar 21
8:30 ROK K%sT 1961 Aug 10
9:00 ROK K%sT
Zone Asia/Pyongyang 8:23:00 - LMT 1908 Apr 1
8:30 - KST 1912 Jan 1
9:00 - JST 1945 Aug 24
9:00 - KST 2015 Aug 15 00:00
8:30 - KST 2018 May 4 23:30
9:00 - KST
###############################################################################
# Kuwait
# See Asia/Riyadh.
# Laos
# See Asia/Bangkok.
# Lebanon
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Lebanon 1920 only - Mar 28 0:00 1:00 S
Rule Lebanon 1920 only - Oct 25 0:00 0 -
Rule Lebanon 1921 only - Apr 3 0:00 1:00 S
Rule Lebanon 1921 only - Oct 3 0:00 0 -
Rule Lebanon 1922 only - Mar 26 0:00 1:00 S
Rule Lebanon 1922 only - Oct 8 0:00 0 -
Rule Lebanon 1923 only - Apr 22 0:00 1:00 S
Rule Lebanon 1923 only - Sep 16 0:00 0 -
Rule Lebanon 1957 1961 - May 1 0:00 1:00 S
Rule Lebanon 1957 1961 - Oct 1 0:00 0 -
Rule Lebanon 1972 only - Jun 22 0:00 1:00 S
Rule Lebanon 1972 1977 - Oct 1 0:00 0 -
Rule Lebanon 1973 1977 - May 1 0:00 1:00 S
Rule Lebanon 1978 only - Apr 30 0:00 1:00 S
Rule Lebanon 1978 only - Sep 30 0:00 0 -
Rule Lebanon 1984 1987 - May 1 0:00 1:00 S
Rule Lebanon 1984 1991 - Oct 16 0:00 0 -
Rule Lebanon 1988 only - Jun 1 0:00 1:00 S
Rule Lebanon 1989 only - May 10 0:00 1:00 S
Rule Lebanon 1990 1992 - May 1 0:00 1:00 S
Rule Lebanon 1992 only - Oct 4 0:00 0 -
Rule Lebanon 1993 max - Mar lastSun 0:00 1:00 S
Rule Lebanon 1993 1998 - Sep lastSun 0:00 0 -
Rule Lebanon 1999 max - Oct lastSun 0:00 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Beirut 2:22:00 - LMT 1880
2:00 Lebanon EE%sT
# Malaysia
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule NBorneo 1935 1941 - Sep 14 0:00 0:20 -
Rule NBorneo 1935 1941 - Dec 14 0:00 0 -
#
# peninsular Malaysia
# taken from Mok Ly Yng (2003-10-30)
# http://www.math.nus.edu.sg/aslaksen/teaching/timezone.html
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Kuala_Lumpur 6:46:46 - LMT 1901 Jan 1
6:55:25 - SMT 1905 Jun 1 # Singapore M.T.
7:00 - +07 1933 Jan 1
7:00 0:20 +0720 1936 Jan 1
7:20 - +0720 1941 Sep 1
7:30 - +0730 1942 Feb 16
9:00 - +09 1945 Sep 12
7:30 - +0730 1982 Jan 1
8:00 - +08
# Sabah & Sarawak
# From Paul Eggert (2014-08-12):
# The data entries here are mostly from Shanks & Pottenger, but the 1942, 1945
# and 1982 transition dates are from Mok Ly Yng.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Kuching 7:21:20 - LMT 1926 Mar
7:30 - +0730 1933
8:00 NBorneo +08/+0820 1942 Feb 16
9:00 - +09 1945 Sep 12
8:00 - +08
# Maldives
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Indian/Maldives 4:54:00 - LMT 1880 # Malé
4:54:00 - MMT 1960 # Malé Mean Time
5:00 - +05
# Mongolia
# Shanks & Pottenger say that Mongolia has three time zones, but
# The USNO (1995-12-21) and the CIA map Standard Time Zones of the World
# (2005-03) both say that it has just one.
# From Oscar van Vlijmen (1999-12-11):
# General Information Mongolia
# <http://www.mongoliatourism.gov.mn/general.htm> (1999-09)
# "Time: Mongolia has two time zones. Three westernmost provinces of
# Bayan-Ölgii, Uvs, and Hovd are one hour earlier than the capital city, and
# the rest of the country follows the Ulaanbaatar time, which is UTC/GMT plus
# eight hours."
# From Rives McDow (1999-12-13):
# Mongolia discontinued the use of daylight savings time in 1999; 1998
# being the last year it was implemented. The dates of implementation I am
# unsure of, but most probably it was similar to Russia, except for the time
# of implementation may have been different....
# Some maps in the past have indicated that there was an additional time
# zone in the eastern part of Mongolia, including the provinces of Dornod,
# Sükhbaatar, and possibly Khentii.
# From Paul Eggert (1999-12-15):
# Naming and spelling is tricky in Mongolia.
# We'll use Hovd (also spelled Chovd and Khovd) to represent the west zone;
# the capital of the Hovd province is sometimes called Hovd, sometimes Dund-Us,
# and sometimes Jirgalanta (with variant spellings), but the name Hovd
# is good enough for our purposes.
# From Rives McDow (2001-05-13):
# In addition to Mongolia starting daylight savings as reported earlier
# (adopted DST on 2001-04-27 02:00 local time, ending 2001-09-28),
# there are three time zones.
#
# Provinces [at 7:00]: Bayan-Ölgii, Uvs, Khovd, Zavkhan, Govi-Altai
# Provinces [at 8:00]: Khövsgöl, Bulgan, Arkhangai, Khentii, Töv,
# Bayankhongor, Övörkhangai, Dundgovi, Dornogovi, Ömnögovi
# Provinces [at 9:00]: Dornod, Sükhbaatar
#
# [The province of Selenge is omitted from the above lists.]
# From Ganbold Ts., Ulaanbaatar (2004-04-17):
# Daylight saving occurs at 02:00 local time last Saturday of March.
# It will change back to normal at 02:00 local time last Saturday of
# September.... As I remember this rule was changed in 2001.
#
# From Paul Eggert (2004-04-17):
# For now, assume Rives McDow's informant got confused about Friday vs
# Saturday, and that his 2001 dates should have 1 added to them.
# From Paul Eggert (2005-07-26):
# We have wildly conflicting information about Mongolia's time zones.
# Bill Bonnet (2005-05-19) reports that the US Embassy in Ulaanbaatar says
# there is only one time zone and that DST is observed, citing Microsoft
# Windows XP as the source. Risto Nykänen (2005-05-16) reports that
# travelmongolia.org says there are two time zones (UT +07, +08) with no DST.
# Oscar van Vlijmen (2005-05-20) reports that the Mongolian Embassy in
# Washington, DC says there are two time zones, with DST observed.
# He also found
# http://ubpost.mongolnews.mn/index.php?subaction=showcomments&id=1111634894&archive=&start_from=&ucat=1&
# which also says that there is DST, and which has a comment by "Toddius"
# (2005-03-31 06:05 +0700) saying "Mongolia actually has 3.5 time zones.
# The West (OLGII) is +7 GMT, most of the country is ULAT is +8 GMT
# and some Eastern provinces are +9 GMT but Sükhbaatar Aimag is SUHK +8.5 GMT.
# The SUKH timezone is new this year, it is one of the few things the
# parliament passed during the tumultuous winter session."
# For now, let's ignore this information, until we have more confirmation.
# From Ganbold Ts. (2007-02-26):
# Parliament of Mongolia has just changed the daylight-saving rule in February.
# They decided not to adopt daylight-saving time....
# http://www.mongolnews.mn/index.php?module=unuudur&sec=view&id=15742
# From Deborah Goldsmith (2008-03-30):
# We received a bug report claiming that the tz database UTC offset for
# Asia/Choibalsan (GMT+09:00) is incorrect, and that it should be GMT
# +08:00 instead. Different sources appear to disagree with the tz
# database on this, e.g.:
#
# https://www.timeanddate.com/worldclock/city.html?n=1026
# http://www.worldtimeserver.com/current_time_in_MN.aspx
#
# both say GMT+08:00.
# From Steffen Thorsen (2008-03-31):
# eznis airways, which operates several domestic flights, has a flight
# schedule here:
# http://www.eznis.com/Container.jsp?id=112
# (click the English flag for English)
#
# There it appears that flights between Choibalsan and Ulaanbaatar arrive
# about 1:35 - 1:50 hours later in local clock time, no matter the
# direction, while Ulaanbaatar-Khovd takes 2 hours in the Eastern
# direction and 3:35 back, which indicates that Ulaanbaatar and Khovd are
# in different time zones (like we know about), while Choibalsan and
# Ulaanbaatar are in the same time zone (correction needed).
# From Arthur David Olson (2008-05-19):
# Assume that Choibalsan is indeed offset by 8:00.
# XXX--in the absence of better information, assume that transition
# was at the start of 2008-03-31 (the day of Steffen Thorsen's report);
# this is almost surely wrong.
# From Ganbold Tsagaankhuu (2015-03-10):
# It seems like yesterday Mongolian Government meeting has concluded to use
# daylight saving time in Mongolia.... Starting at 2:00AM of last Saturday of
# March 2015, daylight saving time starts. And 00:00AM of last Saturday of
# September daylight saving time ends. Source:
# http://zasag.mn/news/view/8969
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Mongol 1983 1984 - Apr 1 0:00 1:00 -
Rule Mongol 1983 only - Oct 1 0:00 0 -
# Shanks & Pottenger and IATA SSIM say 1990s switches occurred at 00:00,
# but McDow says the 2001 switches occurred at 02:00. Also, IATA SSIM
# (1996-09) says 1996-10-25. Go with Shanks & Pottenger through 1998.
#
# Shanks & Pottenger say that the Sept. 1984 through Sept. 1990 switches
# in Choibalsan (more precisely, in Dornod and Sükhbaatar) took place
# at 02:00 standard time, not at 00:00 local time as in the rest of
# the country. That would be odd, and possibly is a result of their
# correction of 02:00 (in the previous edition) not being done correctly
# in the latest edition; so ignore it for now.
# From Ganbold Tsagaankhuu (2017-02-09):
# Mongolian Government meeting has concluded today to cancel daylight
# saving time adoption in Mongolia. Source: http://zasag.mn/news/view/16192
Rule Mongol 1985 1998 - Mar lastSun 0:00 1:00 -
Rule Mongol 1984 1998 - Sep lastSun 0:00 0 -
# IATA SSIM (1999-09) says Mongolia no longer observes DST.
Rule Mongol 2001 only - Apr lastSat 2:00 1:00 -
Rule Mongol 2001 2006 - Sep lastSat 2:00 0 -
Rule Mongol 2002 2006 - Mar lastSat 2:00 1:00 -
Rule Mongol 2015 2016 - Mar lastSat 2:00 1:00 -
Rule Mongol 2015 2016 - Sep lastSat 0:00 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
# Hovd, a.k.a. Chovd, Dund-Us, Dzhargalant, Khovd, Jirgalanta
Zone Asia/Hovd 6:06:36 - LMT 1905 Aug
6:00 - +06 1978
7:00 Mongol +07/+08
# Ulaanbaatar, a.k.a. Ulan Bataar, Ulan Bator, Urga
Zone Asia/Ulaanbaatar 7:07:32 - LMT 1905 Aug
7:00 - +07 1978
8:00 Mongol +08/+09
# Choibalsan, a.k.a. Bajan Tümen, Bajan Tumen, Chojbalsan,
# Choybalsan, Sanbejse, Tchoibalsan
Zone Asia/Choibalsan 7:38:00 - LMT 1905 Aug
7:00 - +07 1978
8:00 - +08 1983 Apr
9:00 Mongol +09/+10 2008 Mar 31
8:00 Mongol +08/+09
# Nepal
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Kathmandu 5:41:16 - LMT 1920
5:30 - +0530 1986
5:45 - +0545
# Oman
# See Asia/Dubai.
# Pakistan
# From Rives McDow (2002-03-13):
# I have been advised that Pakistan has decided to adopt dst on a
# TRIAL basis for one year, starting 00:01 local time on April 7, 2002
# and ending at 00:01 local time October 6, 2002. This is what I was
# told, but I believe that the actual time of change may be 00:00; the
# 00:01 was to make it clear which day it was on.
# From Paul Eggert (2002-03-15):
# Jesper Nørgaard found this URL:
# http://www.pak.gov.pk/public/news/app/app06_dec.htm
# (dated 2001-12-06) which says that the Cabinet adopted a scheme "to
# advance the clocks by one hour on the night between the first
# Saturday and Sunday of April and revert to the original position on
# 15th October each year". This agrees with McDow's 04-07 at 00:00,
# but disagrees about the October transition, and makes it sound like
# it's not on a trial basis. Also, the "between the first Saturday
# and Sunday of April" phrase, if taken literally, means that the
# transition takes place at 00:00 on the first Sunday on or after 04-02.
# From Paul Eggert (2003-02-09):
# DAWN <http://www.dawn.com/2002/10/06/top13.htm> reported on 2002-10-05
# that 2002 DST ended that day at midnight. Go with McDow for now.
# From Steffen Thorsen (2003-03-14):
# According to http://www.dawn.com/2003/03/07/top15.htm
# there will be no DST in Pakistan this year:
#
# ISLAMABAD, March 6: Information and Media Development Minister Sheikh
# Rashid Ahmed on Thursday said the cabinet had reversed a previous
# decision to advance clocks by one hour in summer and put them back by
# one hour in winter with the aim of saving light hours and energy.
#
# The minister told a news conference that the experiment had rather
# shown 8 per cent higher consumption of electricity.
# From Alex Krivenyshev (2008-05-15):
#
# Here is an article that Pakistan plan to introduce Daylight Saving Time
# on June 1, 2008 for 3 months.
#
# "... The federal cabinet on Wednesday announced a new conservation plan to
# help reduce load shedding by approving the closure of commercial centres at
# 9pm and moving clocks forward by one hour for the next three months. ...."
#
# http://www.worldtimezone.com/dst_news/dst_news_pakistan01.html
# http://www.dailytimes.com.pk/default.asp?page=2008%5C05%5C15%5Cstory_15-5-2008_pg1_4
# From Arthur David Olson (2008-05-19):
# XXX--midnight transitions is a guess; 2008 only is a guess.
# From Alexander Krivenyshev (2008-08-28):
# Pakistan government has decided to keep the watches one-hour advanced
# for another 2 months - plan to return to Standard Time on October 31
# instead of August 31.
#
# http://www.worldtimezone.com/dst_news/dst_news_pakistan02.html
# http://dailymailnews.com/200808/28/news/dmbrn03.html
# From Alexander Krivenyshev (2009-04-08):
# Based on previous media reports that "... proposed plan to
# advance clocks by one hour from May 1 will cause disturbance
# to the working schedules rather than bringing discipline in
# official working."
# http://www.thenews.com.pk/daily_detail.asp?id=171280
#
# recent news that instead of May 2009 - Pakistan plan to
# introduce DST from April 15, 2009
#
# FYI: Associated Press Of Pakistan
# April 08, 2009
# Cabinet okays proposal to advance clocks by one hour from April 15
# http://www.app.com.pk/en_/index.php?option=com_content&task=view&id=73043&Itemid=1
# http://www.worldtimezone.com/dst_news/dst_news_pakistan05.html
#
# ....
# The Federal Cabinet on Wednesday approved the proposal to
# advance clocks in the country by one hour from April 15 to
# conserve energy"
# From Steffen Thorsen (2009-09-17):
# "The News International," Pakistan reports that: "The Federal
# Government has decided to restore the previous time by moving the
# clocks backward by one hour from October 1. A formal announcement to
# this effect will be made after the Prime Minister grants approval in
# this regard."
# http://www.thenews.com.pk/updates.asp?id=87168
# From Alexander Krivenyshev (2009-09-28):
# According to Associated Press Of Pakistan, it is confirmed that
# Pakistan clocks across the country would be turned back by an hour from
# October 1, 2009.
#
# "Clocks to go back one hour from 1 Oct"
# http://www.app.com.pk/en_/index.php?option=com_content&task=view&id=86715&Itemid=2
# http://www.worldtimezone.com/dst_news/dst_news_pakistan07.htm
#
# From Steffen Thorsen (2009-09-29):
# Now they seem to have changed their mind, November 1 is the new date:
# http://www.thenews.com.pk/top_story_detail.asp?Id=24742
# "The country's clocks will be reversed by one hour on November 1.
# Officials of Federal Ministry for Interior told this to Geo News on
# Monday."
#
# And more importantly, it seems that these dates will be kept every year:
# "It has now been decided that clocks will be wound forward by one hour
# on April 15 and reversed by an hour on November 1 every year without
# obtaining prior approval, the officials added."
#
# We have confirmed this year's end date with both with the Ministry of
# Water and Power and the Pakistan Electric Power Company:
# https://www.timeanddate.com/news/time/pakistan-ends-dst09.html
# From Christoph Göhre (2009-10-01):
# [T]he German Consulate General in Karachi reported me today that Pakistan
# will go back to standard time on 1st of November.
# From Steffen Thorsen (2010-03-26):
# Steffen Thorsen wrote:
# > On Thursday (2010-03-25) it was announced that DST would start in
# > Pakistan on 2010-04-01.
# >
# > Then today, the president said that they might have to revert the
# > decision if it is not supported by the parliament. So at the time
# > being, it seems unclear if DST will be actually observed or not - but
# > April 1 could be a more likely date than April 15.
# Now, it seems that the decision to not observe DST in final:
#
# "Govt Withdraws Plan To Advance Clocks"
# http://www.apakistannews.com/govt-withdraws-plan-to-advance-clocks-172041
#
# "People laud PM's announcement to end DST"
# http://www.app.com.pk/en_/index.php?option=com_content&task=view&id=99374&Itemid=2
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Pakistan 2002 only - Apr Sun>=2 0:00 1:00 S
Rule Pakistan 2002 only - Oct Sun>=2 0:00 0 -
Rule Pakistan 2008 only - Jun 1 0:00 1:00 S
Rule Pakistan 2008 2009 - Nov 1 0:00 0 -
Rule Pakistan 2009 only - Apr 15 0:00 1:00 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Karachi 4:28:12 - LMT 1907
5:30 - +0530 1942 Sep
5:30 1:00 +0630 1945 Oct 15
5:30 - +0530 1951 Sep 30
5:00 - +05 1971 Mar 26
5:00 Pakistan PK%sT # Pakistan Time
# Palestine
# From Amos Shapir (1998-02-15):
#
# From 1917 until 1948-05-15, all of Palestine, including the parts now
# known as the Gaza Strip and the West Bank, was under British rule.
# Therefore the rules given for Israel for that period, apply there too...
#
# The Gaza Strip was under Egyptian rule between 1948-05-15 until 1967-06-05
# (except a short occupation by Israel from 1956-11 till 1957-03, but no
# time zone was affected then). It was never formally annexed to Egypt,
# though.
#
# The rest of Palestine was under Jordanian rule at that time, formally
# annexed in 1950 as the West Bank (and the word "Trans" was dropped from
# the country's previous name of "the Hashemite Kingdom of the
# Trans-Jordan"). So the rules for Jordan for that time apply. Major
# towns in that area are Nablus (Shchem), El-Halil (Hebron), Ramallah, and
# East Jerusalem.
#
# Both areas were occupied by Israel in June 1967, but not annexed (except
# for East Jerusalem). They were on Israel time since then; there might
# have been a Military Governor's order about time zones, but I'm not aware
# of any (such orders may have been issued semi-annually whenever summer
# time was in effect, but maybe the legal aspect of time was just neglected).
#
# The Palestinian Authority was established in 1993, and got hold of most
# towns in the West Bank and Gaza by 1995. I know that in order to
# demonstrate...independence, they have been switching to
# summer time and back on a different schedule than Israel's, but I don't
# know when this was started, or what algorithm is used (most likely the
# Jordanian one).
#
# To summarize, the table should probably look something like that:
#
# Area \ when | 1918-1947 | 1948-1967 | 1967-1995 | 1996-
# ------------+-----------+-----------+-----------+-----------
# Israel | Zion | Zion | Zion | Zion
# West bank | Zion | Jordan | Zion | Jordan
# Gaza | Zion | Egypt | Zion | Jordan
#
# I guess more info may be available from the PA's web page (if/when they
# have one).
# From Paul Eggert (2006-03-22):
# Shanks & Pottenger write that Gaza did not observe DST until 1957, but go
# with Shapir and assume that it observed DST from 1940 through 1947,
# and that it used Jordanian rules starting in 1996.
# We don't yet need a separate entry for the West Bank, since
# the only differences between it and Gaza that we know about
# occurred before our cutoff date of 1970.
# However, as we get more information, we may need to add entries
# for parts of the West Bank as they transitioned from Israel's rules
# to Palestine's rules.
# From IINS News Service - Israel - 1998-03-23 10:38:07 Israel time,
# forwarded by Ephraim Silverberg:
#
# Despite the fact that Israel changed over to daylight savings time
# last week, the PLO Authority (PA) has decided not to turn its clocks
# one-hour forward at this time. As a sign of independence from Israeli rule,
# the PA has decided to implement DST in April.
# From Paul Eggert (1999-09-20):
# Daoud Kuttab writes in Holiday havoc
# http://www.jpost.com/com/Archive/22.Apr.1999/Opinion/Article-2.html
# (Jerusalem Post, 1999-04-22) that
# the Palestinian National Authority changed to DST on 1999-04-15.
# I vaguely recall that they switch back in October (sorry, forgot the source).
# For now, let's assume that the spring switch was at 24:00,
# and that they switch at 0:00 on the 3rd Fridays of April and October.
# From Paul Eggert (2005-11-22):
# Starting 2004 transitions are from Steffen Thorsen's web site timeanddate.com.
# From Steffen Thorsen (2005-11-23):
# A user from Gaza reported that Gaza made the change early because of
# the Ramadan. Next year Ramadan will be even earlier, so I think
# there is a good chance next year's end date will be around two weeks
# earlier - the same goes for Jordan.
# From Steffen Thorsen (2006-08-17):
# I was informed by a user in Bethlehem that in Bethlehem it started the
# same day as Israel, and after checking with other users in the area, I
# was informed that they started DST one day after Israel. I was not
# able to find any authoritative sources at the time, nor details if
# Gaza changed as well, but presumed Gaza to follow the same rules as
# the West Bank.
# From Steffen Thorsen (2006-09-26):
# according to the Palestine News Network (2006-09-19):
# http://english.pnn.ps/index.php?option=com_content&task=view&id=596&Itemid=5
# > The Council of Ministers announced that this year its winter schedule
# > will begin early, as of midnight Thursday. It is also time to turn
# > back the clocks for winter. Friday will begin an hour late this week.
# I guess it is likely that next year's date will be moved as well,
# because of the Ramadan.
# From Jesper Nørgaard Welen (2007-09-18):
# According to Steffen Thorsen's web site the Gaza Strip and the rest of the
# Palestinian territories left DST early on 13.th. of September at 2:00.
# From Paul Eggert (2007-09-20):
# My understanding is that Gaza and the West Bank disagree even over when
# the weekend is (Thursday+Friday versus Friday+Saturday), so I'd be a bit
# surprised if they agreed about DST. But for now, assume they agree.
# For lack of better information, predict that future changes will be
# the 2nd Thursday of September at 02:00.
# From Alexander Krivenyshev (2008-08-28):
# Here is an article, that Mideast running on different clocks at Ramadan.
#
# Gaza Strip (as Egypt) ended DST at midnight Thursday (Aug 28, 2008), while
# the West Bank will end Daylight Saving Time at midnight Sunday (Aug 31, 2008).
#
# http://www.guardian.co.uk/world/feedarticle/7759001
# http://www.abcnews.go.com/International/wireStory?id=5676087
# http://www.worldtimezone.com/dst_news/dst_news_gazastrip01.html
# From Alexander Krivenyshev (2009-03-26):
# According to the Palestine News Network (arabic.pnn.ps), Palestinian
# government decided to start Daylight Time on Thursday night March
# 26 and continue until the night of 27 September 2009.
#
# (in Arabic)
# http://arabic.pnn.ps/index.php?option=com_content&task=view&id=50850
#
# (English translation)
# http://www.worldtimezone.com/dst_news/dst_news_westbank01.html
# From Steffen Thorsen (2009-08-31):
# Palestine's Council of Ministers announced that they will revert back to
# winter time on Friday, 2009-09-04.
#
# One news source:
# http://www.safa.ps/ara/?action=showdetail&seid=4158
# (Palestinian press agency, Arabic),
# Google translate: "Decided that the Palestinian government in Ramallah
# headed by Salam Fayyad, the start of work in time for the winter of
# 2009, starting on Friday approved the fourth delay Sept. clock sixty
# minutes per hour as of Friday morning."
#
# We are not sure if Gaza will do the same, last year they had a different
# end date, we will keep this page updated:
# https://www.timeanddate.com/news/time/westbank-gaza-dst-2009.html
# From Alexander Krivenyshev (2009-09-02):
# Seems that Gaza Strip will go back to Winter Time same date as West Bank.
#
# According to Palestinian Ministry Of Interior, West Bank and Gaza Strip plan
# to change time back to Standard time on September 4, 2009.
#
# "Winter time unite the West Bank and Gaza"
# (from Palestinian National Authority):
# http://www.moi.gov.ps/en/?page=633167343250594025&nid=11505
# http://www.worldtimezone.com/dst_news/dst_news_gazastrip02.html
# From Alexander Krivenyshev (2010-03-19):
# According to Voice of Palestine DST will last for 191 days, from March
# 26, 2010 till "the last Sunday before the tenth day of Tishri
# (October), each year" (October 03, 2010?)
#
# http://palvoice.org/forums/showthread.php?t=245697
# (in Arabic)
# http://www.worldtimezone.com/dst_news/dst_news_westbank03.html
# From Steffen Thorsen (2010-03-24):
# ...Ma'an News Agency reports that Hamas cabinet has decided it will
# start one day later, at 12:01am. Not sure if they really mean 12:01am or
# noon though:
#
# http://www.maannews.net/eng/ViewDetails.aspx?ID=271178
# (Ma'an News Agency)
# "At 12:01am Friday, clocks in Israel and the West Bank will change to
# 1:01am, while Gaza clocks will change at 12:01am Saturday morning."
# From Steffen Thorsen (2010-08-11):
# According to several sources, including
# http://www.maannews.net/eng/ViewDetails.aspx?ID=306795
# the clocks were set back one hour at 2010-08-11 00:00:00 local time in
# Gaza and the West Bank.
# Some more background info:
# https://www.timeanddate.com/news/time/westbank-gaza-end-dst-2010.html
# From Steffen Thorsen (2011-08-26):
# Gaza and the West Bank did go back to standard time in the beginning of
# August, and will now enter daylight saving time again on 2011-08-30
# 00:00 (so two periods of DST in 2011). The pause was because of
# Ramadan.
#
# http://www.maannews.net/eng/ViewDetails.aspx?ID=416217
# Additional info:
# https://www.timeanddate.com/news/time/palestine-dst-2011.html
# From Alexander Krivenyshev (2011-08-27):
# According to the article in The Jerusalem Post:
# "...Earlier this month, the Palestinian government in the West Bank decided to
# move to standard time for 30 days, during Ramadan. The Palestinians in the
# Gaza Strip accepted the change and also moved their clocks one hour back.
# The Hamas government said on Saturday that it won't observe summertime after
# the Muslim feast of Id al-Fitr, which begins on Tuesday..."
# ...
# https://www.jpost.com/MiddleEast/Article.aspx?id=235650
# http://www.worldtimezone.com/dst_news/dst_news_gazastrip05.html
# The rules for Egypt are stolen from the 'africa' file.
# From Steffen Thorsen (2011-09-30):
# West Bank did end Daylight Saving Time this morning/midnight (2011-09-30
# 00:00).
# So West Bank and Gaza now have the same time again.
#
# Many sources, including:
# http://www.maannews.net/eng/ViewDetails.aspx?ID=424808
# From Steffen Thorsen (2012-03-26):
# Palestinian news sources tell that both Gaza and West Bank will start DST
# on Friday (Thursday midnight, 2012-03-29 24:00).
# Some of many sources in Arabic:
# http://www.samanews.com/index.php?act=Show&id=122638
#
# http://safa.ps/details/news/74352/%D8%A8%D8%AF%D8%A1-%D8%A7%D9%84%D8%AA%D9%88%D9%82%D9%8A%D8%AA-%D8%A7%D9%84%D8%B5%D9%8A%D9%81%D9%8A-%D8%A8%D8%A7%D9%84%D8%B6%D9%81%D8%A9-%D9%88%D8%BA%D8%B2%D8%A9-%D9%84%D9%8A%D9%84%D8%A9-%D8%A7%D9%84%D8%AC%D9%85%D8%B9%D8%A9.html
#
# Our brief summary:
# https://www.timeanddate.com/news/time/gaza-west-bank-dst-2012.html
# From Steffen Thorsen (2013-03-26):
# The following news sources tells that Palestine will "start daylight saving
# time from midnight on Friday, March 29, 2013" (translated).
# [These are in Arabic and are for Gaza and for Ramallah, respectively.]
# http://www.samanews.com/index.php?act=Show&id=154120
# http://safa.ps/details/news/99844/%D8%B1%D8%A7%D9%85-%D8%A7%D9%84%D9%84%D9%87-%D8%A8%D8%AF%D8%A1-%D8%A7%D9%84%D8%AA%D9%88%D9%82%D9%8A%D8%AA-%D8%A7%D9%84%D8%B5%D9%8A%D9%81%D9%8A-29-%D8%A7%D9%84%D8%AC%D8%A7%D8%B1%D9%8A.html
# From Steffen Thorsen (2013-09-24):
# The Gaza and West Bank are ending DST Thursday at midnight
# (2013-09-27 00:00:00) (one hour earlier than last year...).
# This source in English, says "that winter time will go into effect
# at midnight on Thursday in the West Bank and Gaza Strip":
# http://english.wafa.ps/index.php?action=detail&id=23246
# official source...:
# http://www.palestinecabinet.gov.ps/ar/Views/ViewDetails.aspx?pid=1252
# From Steffen Thorsen (2015-03-03):
# Sources such as http://www.alquds.com/news/article/view/id/548257
# and https://www.raya.ps/ar/news/890705.html say Palestine areas will
# start DST on 2015-03-28 00:00 which is one day later than expected.
#
# From Paul Eggert (2015-03-03):
# https://www.timeanddate.com/time/change/west-bank/ramallah?year=2014
# says that the fall 2014 transition was Oct 23 at 24:00.
# From Hannah Kreitem (2016-03-09):
# http://www.palestinecabinet.gov.ps/WebSite/ar/ViewDetails?ID=31728
# [Google translation]: "The Council also decided to start daylight
# saving in Palestine as of one o'clock on Saturday morning,
# 2016-03-26, to provide the clock 60 minutes ahead."
# From Sharef Mustafa (2016-10-19):
# [T]he Palestinian cabinet decision (Mar 8th 2016) published on
# http://www.palestinecabinet.gov.ps/WebSite/Upload/Decree/GOV_17/16032016134830.pdf
# states that summer time will end on Oct 29th at 01:00.
#
# From Tim Parenti (2016-10-19):
# Predict fall transitions on October's last Saturday at 01:00 from now on.
# This is consistent with the 2016 transition as well as our spring
# predictions.
#
# From Paul Eggert (2016-10-19):
# It's also consistent with predictions in the following URLs today:
# https://www.timeanddate.com/time/change/gaza-strip/gaza
# https://www.timeanddate.com/time/change/west-bank/hebron
# From Sharef Mustafa (2018-03-16):
# Palestine summer time will start on Mar 24th 2018 by advancing the
# clock by 60 minutes as per Palestinian cabinet decision published on
# the official website, though the decree did not specify the exact
# time of the time shift.
# http://www.palestinecabinet.gov.ps/Website/AR/NDecrees/ViewFile.ashx?ID=e7a42ab7-ee23-435a-b9c8-a4f7e81f3817
# From Even Scharning (2019-03-23):
# http://pnn.ps/news/401130
# http://palweather.ps/ar/node/50136.html
#
# From Sharif Mustafa (2019-03-26):
# The Palestinian cabinet announced today that the switch to DST will
# be on Fri Mar 29th 2019 by advancing the clock by 60 minutes.
# The decree signing date is Mar 12th but it was not published till today.
# The decree does not specify the exact time of switch.
# http://palestinecabinet.gov.ps/Website/AR/NDecrees/ViewFile.ashx?ID=e54e9ea1-50ee-4137-84df-0d6c78da259b
#
# From Even Scharning (2019-04-10):
# Our source in Palestine said it happened Friday 29 at 00:00 local time....
#
# From Paul Eggert (2019-04-10):
# For now, guess spring-ahead transitions are March's last Friday at 00:00.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule EgyptAsia 1957 only - May 10 0:00 1:00 S
Rule EgyptAsia 1957 1958 - Oct 1 0:00 0 -
Rule EgyptAsia 1958 only - May 1 0:00 1:00 S
Rule EgyptAsia 1959 1967 - May 1 1:00 1:00 S
Rule EgyptAsia 1959 1965 - Sep 30 3:00 0 -
Rule EgyptAsia 1966 only - Oct 1 3:00 0 -
Rule Palestine 1999 2005 - Apr Fri>=15 0:00 1:00 S
Rule Palestine 1999 2003 - Oct Fri>=15 0:00 0 -
Rule Palestine 2004 only - Oct 1 1:00 0 -
Rule Palestine 2005 only - Oct 4 2:00 0 -
Rule Palestine 2006 2007 - Apr 1 0:00 1:00 S
Rule Palestine 2006 only - Sep 22 0:00 0 -
Rule Palestine 2007 only - Sep Thu>=8 2:00 0 -
Rule Palestine 2008 2009 - Mar lastFri 0:00 1:00 S
Rule Palestine 2008 only - Sep 1 0:00 0 -
Rule Palestine 2009 only - Sep Fri>=1 1:00 0 -
Rule Palestine 2010 only - Mar 26 0:00 1:00 S
Rule Palestine 2010 only - Aug 11 0:00 0 -
Rule Palestine 2011 only - Apr 1 0:01 1:00 S
Rule Palestine 2011 only - Aug 1 0:00 0 -
Rule Palestine 2011 only - Aug 30 0:00 1:00 S
Rule Palestine 2011 only - Sep 30 0:00 0 -
Rule Palestine 2012 2014 - Mar lastThu 24:00 1:00 S
Rule Palestine 2012 only - Sep 21 1:00 0 -
Rule Palestine 2013 only - Sep Fri>=21 0:00 0 -
Rule Palestine 2014 2015 - Oct Fri>=21 0:00 0 -
Rule Palestine 2015 only - Mar lastFri 24:00 1:00 S
Rule Palestine 2016 2018 - Mar Sat>=24 1:00 1:00 S
Rule Palestine 2016 max - Oct lastSat 1:00 0 -
Rule Palestine 2019 max - Mar lastFri 0:00 1:00 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Gaza 2:17:52 - LMT 1900 Oct
2:00 Zion EET/EEST 1948 May 15
2:00 EgyptAsia EE%sT 1967 Jun 5
2:00 Zion I%sT 1996
2:00 Jordan EE%sT 1999
2:00 Palestine EE%sT 2008 Aug 29 0:00
2:00 - EET 2008 Sep
2:00 Palestine EE%sT 2010
2:00 - EET 2010 Mar 27 0:01
2:00 Palestine EE%sT 2011 Aug 1
2:00 - EET 2012
2:00 Palestine EE%sT
Zone Asia/Hebron 2:20:23 - LMT 1900 Oct
2:00 Zion EET/EEST 1948 May 15
2:00 EgyptAsia EE%sT 1967 Jun 5
2:00 Zion I%sT 1996
2:00 Jordan EE%sT 1999
2:00 Palestine EE%sT
# Paracel Is
# no information
# Philippines
# From Paul Eggert (2018-11-18):
# The Spanish initially used American (west-of-Greenwich) time.
# It is unknown what time Manila kept when the British occupied it from
# 1762-10-06 through 1764-04; for now assume it kept American time.
# On 1844-08-16, Narciso Clavería, governor-general of the
# Philippines, issued a proclamation announcing that 1844-12-30 was to
# be immediately followed by 1845-01-01; see R.H. van Gent's
# History of the International Date Line
# https://www.staff.science.uu.nl/~gent0113/idl/idl_philippines.htm
# The rest of the data entries are from Shanks & Pottenger.
# From Jesper Nørgaard Welen (2006-04-26):
# ... claims that Philippines had DST last time in 1990:
# http://story.philippinetimes.com/p.x/ct/9/id/145be20cc6b121c0/cid/3e5bbccc730d258c/
# [a story dated 2006-04-25 by Cris Larano of Dow Jones Newswires,
# but no details]
# From Paul Eggert (2014-08-14):
# The following source says DST may be instituted November-January and again
# March-June, but this is not definite. It also says DST was last proclaimed
# during the Ramos administration (1992-1998); but again, no details.
# Carcamo D. PNoy urged to declare use of daylight saving time.
# Philippine Star 2014-08-05
# http://www.philstar.com/headlines/2014/08/05/1354152/pnoy-urged-declare-use-daylight-saving-time
# From Paul Goyette (2018-06-15):
# In the Philippines, there is a national law, Republic Act No. 10535
# which declares the official time here as "Philippine Standard Time".
# The act [1] even specifies use of PST as the abbreviation, although
# the FAQ provided by PAGASA [2] uses the "acronym PhST to distinguish
# it from the Pacific Standard Time (PST)."
# [1] http://www.officialgazette.gov.ph/2013/05/15/republic-act-no-10535/
# [2] https://www1.pagasa.dost.gov.ph/index.php/astronomy/philippine-standard-time#republic-act-10535
#
# From Paul Eggert (2018-06-19):
# I surveyed recent news reports, and my impression is that "PST" is
# more popular among reliable English-language news sources. This is
# not just a measure of Google hit counts: it's also the sizes and
# influence of the sources. There is no current abbreviation for DST,
# so use "PDT", the usual American style.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Phil 1936 only - Nov 1 0:00 1:00 D
Rule Phil 1937 only - Feb 1 0:00 0 S
Rule Phil 1954 only - Apr 12 0:00 1:00 D
Rule Phil 1954 only - Jul 1 0:00 0 S
Rule Phil 1978 only - Mar 22 0:00 1:00 D
Rule Phil 1978 only - Sep 21 0:00 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Manila -15:56:00 - LMT 1844 Dec 31
8:04:00 - LMT 1899 May 11
8:00 Phil P%sT 1942 May
9:00 - JST 1944 Nov
8:00 Phil P%sT
# Qatar
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Qatar 3:26:08 - LMT 1920 # Al Dawhah / Doha
4:00 - +04 1972 Jun
3:00 - +03
Link Asia/Qatar Asia/Bahrain
# Saudi Arabia
#
# From Paul Eggert (2018-08-29):
# Time in Saudi Arabia and other countries in the Arabian peninsula was not
# standardized until 1968 or so; we don't know exactly when, and possibly it
# has never been made official. Richard P Hunt, in "Islam city yielding to
# modern times", New York Times (1961-04-09), p 20, wrote that only airlines
# observed standard time, and that people in Jeddah mostly observed quasi-solar
# time, doing so by setting their watches at sunrise to 6 o'clock (or to 12
# o'clock for "Arab" time).
#
# Timekeeping differed depending on who you were and which part of Saudi
# Arabia you were in. In 1969, Elias Antar wrote that although a common
# practice had been to set one's watch to 12:00 (i.e., midnight) at sunset -
# which meant that the time on one side of a mountain could differ greatly from
# the time on the other side - many foreigners set their watches to 6pm
# instead, while airlines instead used UTC +03 (except in Dhahran, where they
# used UTC +04), Aramco used UTC +03 with DST, and the Trans-Arabian Pipe Line
# Company used Aramco time in eastern Saudi Arabia and airline time in western.
# (The American Military Aid Advisory Group used plain UTC.) Antar writes,
# "A man named Higgins, so the story goes, used to run a local power
# station. One day, the whole thing became too much for Higgins and he
# assembled his staff and laid down the law. 'I've had enough of this,' he
# shrieked. 'It is now 12 o'clock Higgins Time, and from now on this station is
# going to run on Higgins Time.' And so, until last year, it did." See:
# Antar E. Dinner at When? Saudi Aramco World, 1969 March/April. 2-3.
# http://archive.aramcoworld.com/issue/196902/dinner.at.when.htm
# Also see: Antar EN. Arabian flying is confusing.
# Port Angeles (WA) Evening News. 1965-03-10. page 3.
#
# The TZ database cannot represent quasi-solar time; airline time is the best
# we can do. The 1946 foreign air news digest of the U.S. Civil Aeronautics
# Board (OCLC 42299995) reported that the "... Arabian Government, inaugurated
# a weekly Dhahran-Cairo service, via the Saudi Arabian cities of Riyadh and
# Jidda, on March 14, 1947". Shanks & Pottenger guessed 1950; go with the
# earlier date.
#
# Shanks & Pottenger also state that until 1968-05-01 Saudi Arabia had two
# time zones; the other zone, at UT +04, was in the far eastern part of
# the country. Presumably this is documenting airline time. Ignore this,
# as it's before our 1970 cutoff.
#
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Riyadh 3:06:52 - LMT 1947 Mar 14
3:00 - +03
Link Asia/Riyadh Asia/Aden # Yemen
Link Asia/Riyadh Asia/Kuwait
# Singapore
# taken from Mok Ly Yng (2003-10-30)
# http://www.math.nus.edu.sg/aslaksen/teaching/timezone.html
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Singapore 6:55:25 - LMT 1901 Jan 1
6:55:25 - SMT 1905 Jun 1 # Singapore M.T.
7:00 - +07 1933 Jan 1
7:00 0:20 +0720 1936 Jan 1
7:20 - +0720 1941 Sep 1
7:30 - +0730 1942 Feb 16
9:00 - +09 1945 Sep 12
7:30 - +0730 1982 Jan 1
8:00 - +08
# Spratly Is
# no information
# Sri Lanka
# From Paul Eggert (2013-02-21):
# Milne says "Madras mean time use from May 1, 1898. Prior to this Colombo
# mean time, 5h. 4m. 21.9s. F., was used." But 5:04:21.9 differs considerably
# from Colombo's meridian 5:19:24, so for now ignore Milne and stick with
# Shanks and Pottenger.
# From Paul Eggert (1996-09-03):
# "Sri Lanka advances clock by an hour to avoid blackout"
# (<http://www.virtual-pc.com/lankaweb/news/items/240596-2.html>, 1996-05-24,
# no longer available as of 1999-08-17)
# reported "the country's standard time will be put forward by one hour at
# midnight Friday (1830 GMT) 'in the light of the present power crisis'."
#
# From Dharmasiri Senanayake, Sri Lanka Media Minister (1996-10-24), as quoted
# by Shamindra in Daily News - Hot News Section
# <news:54rka5$m5h@mtinsc01-mgt.ops.worldnet.att.net> (1996-10-26):
# With effect from 12.30 a.m. on 26th October 1996
# Sri Lanka will be six (06) hours ahead of GMT.
# From Jesper Nørgaard Welen (2006-04-14), quoting Sri Lanka News Online
# <http://news.sinhalaya.com/wmview.php?ArtID=11002> (2006-04-13):
# 0030 hrs on April 15, 2006 (midnight of April 14, 2006 +30 minutes)
# at present, become 2400 hours of April 14, 2006 (midnight of April 14, 2006).
# From Peter Apps and Ranga Sirila of Reuters (2006-04-12) in:
# http://today.reuters.co.uk/news/newsArticle.aspx?type=scienceNews&storyID=2006-04-12T172228Z_01_COL295762_RTRIDST_0_SCIENCE-SRILANKA-TIME-DC.XML
# [The Tamil Tigers] never accepted the original 1996 time change and simply
# kept their clocks set five and a half hours ahead of Greenwich Mean
# Time (GMT), in line with neighbor India.
# From Paul Eggert (2006-04-18):
# People who live in regions under Tamil control can use [TZ='Asia/Kolkata'],
# as that zone has agreed with the Tamil areas since our cutoff date of 1970.
# From Sadika Sumanapala (2016-10-19):
# According to http://www.sltime.org (maintained by Measurement Units,
# Standards & Services Department, Sri Lanka) abbreviation for Sri Lanka
# standard time is SLST.
#
# From Paul Eggert (2016-10-18):
# "SLST" seems to be reasonably recent and rarely-used outside time
# zone nerd sources. I searched Google News and found three uses of
# it in the International Business Times of India in February and
# March of this year when discussing cricket match times, but nothing
# since then (though there has been a lot of cricket) and nothing in
# other English-language news sources. Our old abbreviation "LKT" is
# even worse. For now, let's use a numeric abbreviation; we can
# switch to "SLST" if it catches on.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Colombo 5:19:24 - LMT 1880
5:19:32 - MMT 1906 # Moratuwa Mean Time
5:30 - +0530 1942 Jan 5
5:30 0:30 +06 1942 Sep
5:30 1:00 +0630 1945 Oct 16 2:00
5:30 - +0530 1996 May 25 0:00
6:30 - +0630 1996 Oct 26 0:30
6:00 - +06 2006 Apr 15 0:30
5:30 - +0530
# Syria
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Syria 1920 1923 - Apr Sun>=15 2:00 1:00 S
Rule Syria 1920 1923 - Oct Sun>=1 2:00 0 -
Rule Syria 1962 only - Apr 29 2:00 1:00 S
Rule Syria 1962 only - Oct 1 2:00 0 -
Rule Syria 1963 1965 - May 1 2:00 1:00 S
Rule Syria 1963 only - Sep 30 2:00 0 -
Rule Syria 1964 only - Oct 1 2:00 0 -
Rule Syria 1965 only - Sep 30 2:00 0 -
Rule Syria 1966 only - Apr 24 2:00 1:00 S
Rule Syria 1966 1976 - Oct 1 2:00 0 -
Rule Syria 1967 1978 - May 1 2:00 1:00 S
Rule Syria 1977 1978 - Sep 1 2:00 0 -
Rule Syria 1983 1984 - Apr 9 2:00 1:00 S
Rule Syria 1983 1984 - Oct 1 2:00 0 -
Rule Syria 1986 only - Feb 16 2:00 1:00 S
Rule Syria 1986 only - Oct 9 2:00 0 -
Rule Syria 1987 only - Mar 1 2:00 1:00 S
Rule Syria 1987 1988 - Oct 31 2:00 0 -
Rule Syria 1988 only - Mar 15 2:00 1:00 S
Rule Syria 1989 only - Mar 31 2:00 1:00 S
Rule Syria 1989 only - Oct 1 2:00 0 -
Rule Syria 1990 only - Apr 1 2:00 1:00 S
Rule Syria 1990 only - Sep 30 2:00 0 -
Rule Syria 1991 only - Apr 1 0:00 1:00 S
Rule Syria 1991 1992 - Oct 1 0:00 0 -
Rule Syria 1992 only - Apr 8 0:00 1:00 S
Rule Syria 1993 only - Mar 26 0:00 1:00 S
Rule Syria 1993 only - Sep 25 0:00 0 -
# IATA SSIM (1998-02) says 1998-04-02;
# (1998-09) says 1999-03-29 and 1999-09-29; (1999-02) says 1999-04-02,
# 2000-04-02, and 2001-04-02; (1999-09) says 2000-03-31 and 2001-03-31;
# (2006) says 2006-03-31 and 2006-09-22;
# for now ignore all these claims and go with Shanks & Pottenger,
# except for the 2006-09-22 claim (which seems right for Ramadan).
Rule Syria 1994 1996 - Apr 1 0:00 1:00 S
Rule Syria 1994 2005 - Oct 1 0:00 0 -
Rule Syria 1997 1998 - Mar lastMon 0:00 1:00 S
Rule Syria 1999 2006 - Apr 1 0:00 1:00 S
# From Stephen Colebourne (2006-09-18):
# According to IATA data, Syria will change DST on 21st September [21:00 UTC]
# this year [only].... This is probably related to Ramadan, like Egypt.
Rule Syria 2006 only - Sep 22 0:00 0 -
# From Paul Eggert (2007-03-29):
# Today the AP reported "Syria will switch to summertime at midnight Thursday."
# http://www.iht.com/articles/ap/2007/03/29/africa/ME-GEN-Syria-Time-Change.php
Rule Syria 2007 only - Mar lastFri 0:00 1:00 S
# From Jesper Nørgaard (2007-10-27):
# The sister center ICARDA of my work CIMMYT is confirming that Syria DST will
# not take place 1st November at 0:00 o'clock but 1st November at 24:00 or
# rather Midnight between Thursday and Friday. This does make more sense than
# having it between Wednesday and Thursday (two workdays in Syria) since the
# weekend in Syria is not Saturday and Sunday, but Friday and Saturday. So now
# it is implemented at midnight of the last workday before weekend...
#
# From Steffen Thorsen (2007-10-27):
# Jesper Nørgaard Welen wrote:
#
# > "Winter local time in Syria will be observed at midnight of Thursday 1
# > November 2007, and the clock will be put back 1 hour."
#
# I found confirmation on this in this gov.sy-article (Arabic):
# http://wehda.alwehda.gov.sy/_print_veiw.asp?FileName=12521710520070926111247
#
# which using Google's translate tools says:
# Council of Ministers also approved the commencement of work on
# identifying the winter time as of Friday, 2/11/2007 where the 60th
# minute delay at midnight Thursday 1/11/2007.
Rule Syria 2007 only - Nov Fri>=1 0:00 0 -
# From Stephen Colebourne (2008-03-17):
# For everyone's info, I saw an IATA time zone change for [Syria] for
# this month (March 2008) in the last day or so....
# Country Time Standard --- DST Start --- --- DST End --- DST
# Name Zone Variation Time Date Time Date
# Variation
# Syrian Arab
# Republic SY +0200 2200 03APR08 2100 30SEP08 +0300
# 2200 02APR09 2100 30SEP09 +0300
# 2200 01APR10 2100 30SEP10 +0300
# From Arthur David Olson (2008-03-17):
# Here's a link to English-language coverage by the Syrian Arab News
# Agency (SANA)...
# http://www.sana.sy/eng/21/2008/03/11/165173.htm
# ...which reads (in part) "The Cabinet approved the suggestion of the
# Ministry of Electricity to begin daylight savings time on Friday April
# 4th, advancing clocks one hour ahead on midnight of Thursday April 3rd."
# Since Syria is two hours east of UTC, the 2200 and 2100 transition times
# shown above match up with midnight in Syria.
# From Arthur David Olson (2008-03-18):
# My best guess at a Syrian rule is "the Friday nearest April 1";
# coding that involves either using a "Mar Fri>=29" construct that old time zone
# compilers can't handle or having multiple Rules (a la Israel).
# For now, use "Apr Fri>=1", and go with IATA on a uniform Sep 30 end.
# From Steffen Thorsen (2008-10-07):
# Syria has now officially decided to end DST on 2008-11-01 this year,
# according to the following article in the Syrian Arab News Agency (SANA).
#
# The article is in Arabic, and seems to tell that they will go back to
# winter time on 2008-11-01 at 00:00 local daylight time (delaying/setting
# clocks back 60 minutes).
#
# http://sana.sy/ara/2/2008/10/07/195459.htm
# From Steffen Thorsen (2009-03-19):
# Syria will start DST on 2009-03-27 00:00 this year according to many sources,
# two examples:
#
# http://www.sana.sy/eng/21/2009/03/17/217563.htm
# (English, Syrian Arab News # Agency)
# http://thawra.alwehda.gov.sy/_View_news2.asp?FileName=94459258720090318012209
# (Arabic, gov-site)
#
# We have not found any sources saying anything about when DST ends this year.
#
# Our summary
# https://www.timeanddate.com/news/time/syria-dst-starts-march-27-2009.html
# From Steffen Thorsen (2009-10-27):
# The Syrian Arab News Network on 2009-09-29 reported that Syria will
# revert back to winter (standard) time on midnight between Thursday
# 2009-10-29 and Friday 2009-10-30:
# http://www.sana.sy/ara/2/2009/09/29/247012.htm (Arabic)
# From Arthur David Olson (2009-10-28):
# We'll see if future DST switching times turn out to be end of the last
# Thursday of the month or the start of the last Friday of the month or
# something else. For now, use the start of the last Friday.
# From Steffen Thorsen (2010-03-17):
# The "Syrian News Station" reported on 2010-03-16 that the Council of
# Ministers has decided that Syria will start DST on midnight Thursday
# 2010-04-01: (midnight between Thursday and Friday):
# http://sns.sy/sns/?path=news/read/11421 (Arabic)
# From Steffen Thorsen (2012-03-26):
# Today, Syria's government announced that they will start DST early on Friday
# (00:00). This is a bit earlier than the past two years.
#
# From Syrian Arab News Agency, in Arabic:
# http://www.sana.sy/ara/2/2012/03/26/408215.htm
#
# Our brief summary:
# https://www.timeanddate.com/news/time/syria-dst-2012.html
# From Arthur David Olson (2012-03-27):
# Assume last Friday in March going forward XXX.
Rule Syria 2008 only - Apr Fri>=1 0:00 1:00 S
Rule Syria 2008 only - Nov 1 0:00 0 -
Rule Syria 2009 only - Mar lastFri 0:00 1:00 S
Rule Syria 2010 2011 - Apr Fri>=1 0:00 1:00 S
Rule Syria 2012 max - Mar lastFri 0:00 1:00 S
Rule Syria 2009 max - Oct lastFri 0:00 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Damascus 2:25:12 - LMT 1920 # Dimashq
2:00 Syria EE%sT
# Tajikistan
# From Shanks & Pottenger.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Dushanbe 4:35:12 - LMT 1924 May 2
5:00 - +05 1930 Jun 21
6:00 RussiaAsia +06/+07 1991 Mar 31 2:00s
5:00 1:00 +05/+06 1991 Sep 9 2:00s
5:00 - +05
# Thailand
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Bangkok 6:42:04 - LMT 1880
6:42:04 - BMT 1920 Apr # Bangkok Mean Time
7:00 - +07
Link Asia/Bangkok Asia/Phnom_Penh # Cambodia
Link Asia/Bangkok Asia/Vientiane # Laos
# Turkmenistan
# From Shanks & Pottenger.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Ashgabat 3:53:32 - LMT 1924 May 2 # or Ashkhabad
4:00 - +04 1930 Jun 21
5:00 RussiaAsia +05/+06 1991 Mar 31 2:00
4:00 RussiaAsia +04/+05 1992 Jan 19 2:00
5:00 - +05
# United Arab Emirates
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Dubai 3:41:12 - LMT 1920
4:00 - +04
Link Asia/Dubai Asia/Muscat # Oman
# Uzbekistan
# Byalokoz 1919 says Uzbekistan was 4:27:53.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Samarkand 4:27:53 - LMT 1924 May 2
4:00 - +04 1930 Jun 21
5:00 - +05 1981 Apr 1
5:00 1:00 +06 1981 Oct 1
6:00 - +06 1982 Apr 1
5:00 RussiaAsia +05/+06 1992
5:00 - +05
# Milne says Tashkent was 4:37:10.8; round to nearest.
Zone Asia/Tashkent 4:37:11 - LMT 1924 May 2
5:00 - +05 1930 Jun 21
6:00 RussiaAsia +06/+07 1991 Mar 31 2:00
5:00 RussiaAsia +05/+06 1992
5:00 - +05
# Vietnam
# From Paul Eggert (2014-10-04):
# Milne gives 7:16:56 for the meridian of Saigon in 1899, as being
# used in Lower Laos, Cambodia, and Annam. But this is quite a ways
# from Saigon's location. For now, ignore this and stick with Shanks
# and Pottenger for LMT before 1906.
# From Arthur David Olson (2008-03-18):
# The English-language name of Vietnam's most populous city is "Ho Chi Minh
# City"; use Ho_Chi_Minh below to avoid a name of more than 14 characters.
# From Paul Eggert (2014-10-21) after a heads-up from Trần Ngọc Quân:
# Trần Tiến Bình's authoritative book "Lịch Việt Nam: thế kỷ XX-XXI (1901-2100)"
# (Nhà xuất bản Văn Hoá - Thông Tin, Hanoi, 2005), pp 49-50,
# is quoted verbatim in:
# http://www.thoigian.com.vn/?mPage=P80D01
# is translated by Brian Inglis in:
# https://mm.icann.org/pipermail/tz/2014-October/021654.html
# and is the basis for the information below.
#
# The 1906 transition was effective July 1 and standardized Indochina to
# Phù Liễn Observatory, legally 104° 17' 17" east of Paris.
# It's unclear whether this meant legal Paris Mean Time (00:09:21) or
# the Paris Meridian (2° 20' 14.03" E); the former yields 07:06:30.1333...
# and the latter 07:06:29.333... so either way it rounds to 07:06:30,
# which is used below even though the modern-day Phù Liễn Observatory
# is closer to 07:06:31. Abbreviate Phù Liễn Mean Time as PLMT.
#
# The following transitions occurred in Indochina in general (before 1954)
# and in South Vietnam in particular (after 1954):
# To 07:00 on 1911-05-01.
# To 08:00 on 1942-12-31 at 23:00.
-# To 09:00 in 1945-03-14 at 23:00.
+# To 09:00 on 1945-03-14 at 23:00.
# To 07:00 on 1945-09-02 in Vietnam.
# To 08:00 on 1947-04-01 in French-controlled Indochina.
# To 07:00 on 1955-07-01 in South Vietnam.
# To 08:00 on 1959-12-31 at 23:00 in South Vietnam.
# To 07:00 on 1975-06-13 in South Vietnam.
#
# Trần cites the following sources; it's unclear which supplied the info above.
#
# Hoàng Xuân Hãn: "Lịch và lịch Việt Nam". Tập san Khoa học Xã hội,
# No. 9, Paris, February 1982.
#
# Lê Thành Lân: "Lịch và niên biểu lịch sử hai mươi thế kỷ (0001-2010)",
# NXB Thống kê, Hanoi, 2000.
#
# Lê Thành Lân: "Lịch hai thế kỷ (1802-2010) và các lịch vĩnh cửu",
# NXB Thuận Hoá, Huế, 1995.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Ho_Chi_Minh 7:06:40 - LMT 1906 Jul 1
7:06:30 - PLMT 1911 May 1 # Phù Liễn MT
7:00 - +07 1942 Dec 31 23:00
8:00 - +08 1945 Mar 14 23:00
9:00 - +09 1945 Sep 2
7:00 - +07 1947 Apr 1
8:00 - +08 1955 Jul 1
7:00 - +07 1959 Dec 31 23:00
8:00 - +08 1975 Jun 13
7:00 - +07
# From Paul Eggert (2019-02-19):
#
# The Ho Chi Minh entry suffices for most purposes as it agrees with all of
# Vietnam since 1975-06-13. Presumably clocks often changed in south Vietnam
# in the early 1970s as locations changed hands during the war; however the
# details are unknown and would likely be too voluminous for this database.
#
# For timestamps in north Vietnam back to 1970 (the tzdb cutoff),
# use Asia/Bangkok; see the VN entries in the file zone1970.tab.
# For timestamps before 1970, see Asia/Hanoi in the file 'backzone'.
# Yemen
# See Asia/Riyadh.
Index: stable/12/contrib/tzdata/australasia
===================================================================
--- stable/12/contrib/tzdata/australasia (revision 352352)
+++ stable/12/contrib/tzdata/australasia (revision 352353)
@@ -1,2098 +1,2114 @@
# tzdb data for Australasia and environs, and for much of the Pacific
# This file is in the public domain, so clarified as of
# 2009-05-17 by Arthur David Olson.
# This file also includes Pacific islands.
# Notes are at the end of this file
###############################################################################
# Australia
# Please see the notes below for the controversy about "EST" versus "AEST" etc.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Aus 1917 only - Jan 1 0:01 1:00 D
Rule Aus 1917 only - Mar 25 2:00 0 S
Rule Aus 1942 only - Jan 1 2:00 1:00 D
Rule Aus 1942 only - Mar 29 2:00 0 S
Rule Aus 1942 only - Sep 27 2:00 1:00 D
Rule Aus 1943 1944 - Mar lastSun 2:00 0 S
Rule Aus 1943 only - Oct 3 2:00 1:00 D
# Go with Whitman and the Australian National Standards Commission, which
# says W Australia didn't use DST in 1943/1944. Ignore Whitman's claim that
# 1944/1945 was just like 1943/1944.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
# Northern Territory
Zone Australia/Darwin 8:43:20 - LMT 1895 Feb
9:00 - ACST 1899 May
9:30 Aus AC%sT
# Western Australia
#
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule AW 1974 only - Oct lastSun 2:00s 1:00 D
Rule AW 1975 only - Mar Sun>=1 2:00s 0 S
Rule AW 1983 only - Oct lastSun 2:00s 1:00 D
Rule AW 1984 only - Mar Sun>=1 2:00s 0 S
Rule AW 1991 only - Nov 17 2:00s 1:00 D
Rule AW 1992 only - Mar Sun>=1 2:00s 0 S
Rule AW 2006 only - Dec 3 2:00s 1:00 D
Rule AW 2007 2009 - Mar lastSun 2:00s 0 S
Rule AW 2007 2008 - Oct lastSun 2:00s 1:00 D
Zone Australia/Perth 7:43:24 - LMT 1895 Dec
8:00 Aus AW%sT 1943 Jul
8:00 AW AW%sT
Zone Australia/Eucla 8:35:28 - LMT 1895 Dec
8:45 Aus +0845/+0945 1943 Jul
8:45 AW +0845/+0945
# Queensland
#
# From Alex Livingston (1996-11-01):
# I have heard or read more than once that some resort islands off the coast
# of Queensland chose to keep observing daylight-saving time even after
# Queensland ceased to.
#
# From Paul Eggert (1996-11-22):
# IATA SSIM (1993-02/1994-09) say that the Holiday Islands (Hayman, Lindeman,
# Hamilton) observed DST for two years after the rest of Queensland stopped.
# Hamilton is the largest, but there is also a Hamilton in Victoria,
# so use Lindeman.
#
# From J William Piggott (2016-02-20):
# There is no location named Holiday Islands in Queensland Australia; holiday
# islands is a colloquial term used globally. Hayman and Lindeman are at the
# north and south extremes of the Whitsunday Islands archipelago, and
# Hamilton is in between; it is reasonable to believe that this time zone
# applies to all of the Whitsundays.
# http://www.australia.gov.au/about-australia/australian-story/austn-islands
#
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule AQ 1971 only - Oct lastSun 2:00s 1:00 D
Rule AQ 1972 only - Feb lastSun 2:00s 0 S
Rule AQ 1989 1991 - Oct lastSun 2:00s 1:00 D
Rule AQ 1990 1992 - Mar Sun>=1 2:00s 0 S
Rule Holiday 1992 1993 - Oct lastSun 2:00s 1:00 D
Rule Holiday 1993 1994 - Mar Sun>=1 2:00s 0 S
Zone Australia/Brisbane 10:12:08 - LMT 1895
10:00 Aus AE%sT 1971
10:00 AQ AE%sT
Zone Australia/Lindeman 9:55:56 - LMT 1895
10:00 Aus AE%sT 1971
10:00 AQ AE%sT 1992 Jul
10:00 Holiday AE%sT
# South Australia
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule AS 1971 1985 - Oct lastSun 2:00s 1:00 D
Rule AS 1986 only - Oct 19 2:00s 1:00 D
Rule AS 1987 2007 - Oct lastSun 2:00s 1:00 D
Rule AS 1972 only - Feb 27 2:00s 0 S
Rule AS 1973 1985 - Mar Sun>=1 2:00s 0 S
Rule AS 1986 1990 - Mar Sun>=15 2:00s 0 S
Rule AS 1991 only - Mar 3 2:00s 0 S
Rule AS 1992 only - Mar 22 2:00s 0 S
Rule AS 1993 only - Mar 7 2:00s 0 S
Rule AS 1994 only - Mar 20 2:00s 0 S
Rule AS 1995 2005 - Mar lastSun 2:00s 0 S
Rule AS 2006 only - Apr 2 2:00s 0 S
Rule AS 2007 only - Mar lastSun 2:00s 0 S
Rule AS 2008 max - Apr Sun>=1 2:00s 0 S
Rule AS 2008 max - Oct Sun>=1 2:00s 1:00 D
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Australia/Adelaide 9:14:20 - LMT 1895 Feb
9:00 - ACST 1899 May
9:30 Aus AC%sT 1971
9:30 AS AC%sT
# Tasmania
#
# From Paul Eggert (2005-08-16):
# http://www.bom.gov.au/climate/averages/tables/dst_times.shtml
# says King Island didn't observe DST from WWII until late 1971.
#
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule AT 1967 only - Oct Sun>=1 2:00s 1:00 D
Rule AT 1968 only - Mar lastSun 2:00s 0 S
Rule AT 1968 1985 - Oct lastSun 2:00s 1:00 D
Rule AT 1969 1971 - Mar Sun>=8 2:00s 0 S
Rule AT 1972 only - Feb lastSun 2:00s 0 S
Rule AT 1973 1981 - Mar Sun>=1 2:00s 0 S
Rule AT 1982 1983 - Mar lastSun 2:00s 0 S
Rule AT 1984 1986 - Mar Sun>=1 2:00s 0 S
Rule AT 1986 only - Oct Sun>=15 2:00s 1:00 D
Rule AT 1987 1990 - Mar Sun>=15 2:00s 0 S
Rule AT 1987 only - Oct Sun>=22 2:00s 1:00 D
Rule AT 1988 1990 - Oct lastSun 2:00s 1:00 D
Rule AT 1991 1999 - Oct Sun>=1 2:00s 1:00 D
Rule AT 1991 2005 - Mar lastSun 2:00s 0 S
Rule AT 2000 only - Aug lastSun 2:00s 1:00 D
Rule AT 2001 max - Oct Sun>=1 2:00s 1:00 D
Rule AT 2006 only - Apr Sun>=1 2:00s 0 S
Rule AT 2007 only - Mar lastSun 2:00s 0 S
Rule AT 2008 max - Apr Sun>=1 2:00s 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Australia/Hobart 9:49:16 - LMT 1895 Sep
10:00 - AEST 1916 Oct 1 2:00
10:00 1:00 AEDT 1917 Feb
10:00 Aus AE%sT 1967
10:00 AT AE%sT
Zone Australia/Currie 9:35:28 - LMT 1895 Sep
10:00 - AEST 1916 Oct 1 2:00
10:00 1:00 AEDT 1917 Feb
10:00 Aus AE%sT 1971 Jul
10:00 AT AE%sT
# Victoria
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule AV 1971 1985 - Oct lastSun 2:00s 1:00 D
Rule AV 1972 only - Feb lastSun 2:00s 0 S
Rule AV 1973 1985 - Mar Sun>=1 2:00s 0 S
Rule AV 1986 1990 - Mar Sun>=15 2:00s 0 S
Rule AV 1986 1987 - Oct Sun>=15 2:00s 1:00 D
Rule AV 1988 1999 - Oct lastSun 2:00s 1:00 D
Rule AV 1991 1994 - Mar Sun>=1 2:00s 0 S
Rule AV 1995 2005 - Mar lastSun 2:00s 0 S
Rule AV 2000 only - Aug lastSun 2:00s 1:00 D
Rule AV 2001 2007 - Oct lastSun 2:00s 1:00 D
Rule AV 2006 only - Apr Sun>=1 2:00s 0 S
Rule AV 2007 only - Mar lastSun 2:00s 0 S
Rule AV 2008 max - Apr Sun>=1 2:00s 0 S
Rule AV 2008 max - Oct Sun>=1 2:00s 1:00 D
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Australia/Melbourne 9:39:52 - LMT 1895 Feb
10:00 Aus AE%sT 1971
10:00 AV AE%sT
# New South Wales
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule AN 1971 1985 - Oct lastSun 2:00s 1:00 D
Rule AN 1972 only - Feb 27 2:00s 0 S
Rule AN 1973 1981 - Mar Sun>=1 2:00s 0 S
Rule AN 1982 only - Apr Sun>=1 2:00s 0 S
Rule AN 1983 1985 - Mar Sun>=1 2:00s 0 S
Rule AN 1986 1989 - Mar Sun>=15 2:00s 0 S
Rule AN 1986 only - Oct 19 2:00s 1:00 D
Rule AN 1987 1999 - Oct lastSun 2:00s 1:00 D
Rule AN 1990 1995 - Mar Sun>=1 2:00s 0 S
Rule AN 1996 2005 - Mar lastSun 2:00s 0 S
Rule AN 2000 only - Aug lastSun 2:00s 1:00 D
Rule AN 2001 2007 - Oct lastSun 2:00s 1:00 D
Rule AN 2006 only - Apr Sun>=1 2:00s 0 S
Rule AN 2007 only - Mar lastSun 2:00s 0 S
Rule AN 2008 max - Apr Sun>=1 2:00s 0 S
Rule AN 2008 max - Oct Sun>=1 2:00s 1:00 D
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Australia/Sydney 10:04:52 - LMT 1895 Feb
10:00 Aus AE%sT 1971
10:00 AN AE%sT
Zone Australia/Broken_Hill 9:25:48 - LMT 1895 Feb
10:00 - AEST 1896 Aug 23
9:00 - ACST 1899 May
9:30 Aus AC%sT 1971
9:30 AN AC%sT 2000
9:30 AS AC%sT
# Lord Howe Island
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule LH 1981 1984 - Oct lastSun 2:00 1:00 -
Rule LH 1982 1985 - Mar Sun>=1 2:00 0 -
Rule LH 1985 only - Oct lastSun 2:00 0:30 -
Rule LH 1986 1989 - Mar Sun>=15 2:00 0 -
Rule LH 1986 only - Oct 19 2:00 0:30 -
Rule LH 1987 1999 - Oct lastSun 2:00 0:30 -
Rule LH 1990 1995 - Mar Sun>=1 2:00 0 -
Rule LH 1996 2005 - Mar lastSun 2:00 0 -
Rule LH 2000 only - Aug lastSun 2:00 0:30 -
Rule LH 2001 2007 - Oct lastSun 2:00 0:30 -
Rule LH 2006 only - Apr Sun>=1 2:00 0 -
Rule LH 2007 only - Mar lastSun 2:00 0 -
Rule LH 2008 max - Apr Sun>=1 2:00 0 -
Rule LH 2008 max - Oct Sun>=1 2:00 0:30 -
Zone Australia/Lord_Howe 10:36:20 - LMT 1895 Feb
10:00 - AEST 1981 Mar
10:30 LH +1030/+1130 1985 Jul
10:30 LH +1030/+11
# Australian miscellany
#
# Ashmore Is, Cartier
# no indigenous inhabitants; only seasonal caretakers
# no times are set
#
# Coral Sea Is
# no indigenous inhabitants; only meteorologists
# no times are set
#
# Macquarie
# Permanent occupation (scientific station) 1911-1915 and since 25 March 1948;
# sealing and penguin oil station operated Nov 1899 to Apr 1919. See the
# Tasmania Parks & Wildlife Service history of sealing at Macquarie Island
# http://www.parks.tas.gov.au/index.aspx?base=1828
# http://www.parks.tas.gov.au/index.aspx?base=1831
# Guess that it was like Australia/Hobart while inhabited before 2010.
#
# From Steffen Thorsen (2010-03-10):
# We got these changes from the Australian Antarctic Division:
# - Macquarie Island will stay on UTC+11 for winter and therefore not
# switch back from daylight savings time when other parts of Australia do
# on 4 April.
#
# From Arthur David Olson (2013-05-23):
# The 1919 transition is overspecified below so pre-2013 zics
# will produce a binary file with an [A]EST-type as the first 32-bit type;
# this is required for correct handling of times before 1916 by
# pre-2013 versions of localtime.
Zone Antarctica/Macquarie 0 - -00 1899 Nov
10:00 - AEST 1916 Oct 1 2:00
10:00 1:00 AEDT 1917 Feb
10:00 Aus AE%sT 1919 Apr 1 0:00s
0 - -00 1948 Mar 25
10:00 Aus AE%sT 1967
10:00 AT AE%sT 2010 Apr 4 3:00
11:00 - +11
# Christmas
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Indian/Christmas 7:02:52 - LMT 1895 Feb
7:00 - +07
# Cocos (Keeling) Is
# These islands were ruled by the Ross family from about 1830 to 1978.
# We don't know when standard time was introduced; for now, we guess 1900.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Indian/Cocos 6:27:40 - LMT 1900
6:30 - +0630
# Fiji
# Milne gives 11:55:44 for Suva.
# From Alexander Krivenyshev (2009-11-10):
# According to Fiji Broadcasting Corporation, Fiji plans to re-introduce DST
# from November 29th 2009 to April 25th 2010.
#
# "Daylight savings to commence this month"
# http://www.radiofiji.com.fj/fullstory.php?id=23719
# http://www.worldtimezone.com/dst_news/dst_news_fiji01.html
# From Steffen Thorsen (2009-11-10):
# The Fiji Government has posted some more details about the approved
# amendments:
# http://www.fiji.gov.fj/publish/page_16198.shtml
# From Steffen Thorsen (2010-03-03):
# The Cabinet in Fiji has decided to end DST about a month early, on
# 2010-03-28 at 03:00.
# The plan is to observe DST again, from 2010-10-24 to sometime in March
# 2011 (last Sunday a good guess?).
#
# Official source:
# http://www.fiji.gov.fj/index.php?option=com_content&view=article&id=1096:3310-cabinet-approves-change-in-daylight-savings-dates&catid=49:cabinet-releases&Itemid=166
#
# A bit more background info here:
# https://www.timeanddate.com/news/time/fiji-dst-ends-march-2010.html
# From Alexander Krivenyshev (2010-10-24):
# According to Radio Fiji and Fiji Times online, Fiji will end DST 3
# weeks earlier than expected - on March 6, 2011, not March 27, 2011...
# Here is confirmation from Government of the Republic of the Fiji Islands,
# Ministry of Information (fiji.gov.fj) web site:
# http://www.fiji.gov.fj/index.php?option=com_content&view=article&id=2608:daylight-savings&catid=71:press-releases&Itemid=155
# http://www.worldtimezone.com/dst_news/dst_news_fiji04.html
# From Steffen Thorsen (2011-10-03):
# Now the dates have been confirmed, and at least our start date
# assumption was correct (end date was one week wrong).
#
# http://www.fiji.gov.fj/index.php?option=com_content&view=article&id=4966:daylight-saving-starts-in-fiji&catid=71:press-releases&Itemid=155
# which says
# Members of the public are reminded to change their time to one hour in
# advance at 2am to 3am on October 23, 2011 and one hour back at 3am to
# 2am on February 26 next year.
# From Ken Rylander (2011-10-24)
# Another change to the Fiji DST end date. In the TZ database the end date for
# Fiji DST 2012, is currently Feb 26. This has been changed to Jan 22.
#
# http://www.fiji.gov.fj/index.php?option=com_content&view=article&id=5017:amendments-to-daylight-savings&catid=71:press-releases&Itemid=155
# states:
#
# The end of daylight saving scheduled initially for the 26th of February 2012
# has been brought forward to the 22nd of January 2012.
# The commencement of daylight saving will remain unchanged and start
# on the 23rd of October, 2011.
# From the Fiji Government Online Portal (2012-08-21) via Steffen Thorsen:
# The Minister for Labour, Industrial Relations and Employment Mr Jone Usamate
# today confirmed that Fiji will start daylight savings at 2 am on Sunday 21st
# October 2012 and end at 3 am on Sunday 20th January 2013.
# http://www.fiji.gov.fj/index.php?option=com_content&view=article&id=6702&catid=71&Itemid=155
# From the Fijian Government Media Center (2013-08-30) via David Wheeler:
# Fiji will start daylight savings on Sunday 27th October, 2013 ...
# move clocks forward by one hour from 2am
# http://www.fiji.gov.fj/Media-Center/Press-Releases/DAYLIGHT-SAVING-STARTS-ON-SUNDAY,-27th-OCTOBER-201.aspx
# From Steffen Thorsen (2013-01-10):
# Fiji will end DST on 2014-01-19 02:00:
# http://www.fiji.gov.fj/Media-Center/Press-Releases/DAYLIGHT-SAVINGS-TO-END-THIS-MONTH-%281%29.aspx
# From Ken Rylander (2014-10-20):
# DST will start Nov. 2 this year.
# http://www.fiji.gov.fj/Media-Center/Press-Releases/DAYLIGHT-SAVING-STARTS-ON-SUNDAY,-NOVEMBER-2ND.aspx
# From a government order dated 2015-08-26 and published as Legal Notice No. 77
# in the Government of Fiji Gazette Supplement No. 24 (2015-08-28),
# via Ken Rylander (2015-09-02):
# the daylight saving period is 1 hour in advance of the standard time
# commencing at 2.00 am on Sunday 1st November, 2015 and ending at
# 3.00 am on Sunday 17th January, 2016.
# From Raymond Kumar (2016-10-04):
# http://www.fiji.gov.fj/Media-Center/Press-Releases/DAYLIGHT-SAVING-STARTS-ON-6th-NOVEMBER,-2016.aspx
# "Fiji's daylight savings will begin on Sunday, 6 November 2016, when
# clocks go forward an hour at 2am to 3am.... Daylight Saving will
# end at 3.00am on Sunday 15th January 2017."
# From Paul Eggert (2017-08-21):
# Dominic Fok writes (2017-08-20) that DST ends 2018-01-14, citing
# Extraordinary Government of Fiji Gazette Supplement No. 21 (2017-08-27),
# [Legal Notice No. 41] of an order of the previous day by J Usamate.
# From Raymond Kumar (2018-07-13):
# http://www.fijitimes.com/government-approves-2018-daylight-saving/
# ... The daylight saving period will end at 3am on Sunday January 13, 2019.
-#
-# From Paul Eggert (2018-07-15):
-# For now, guess DST from 02:00 the first Sunday in November to 03:00
-# the first Sunday on or after January 13. January transitions reportedly
+
+# From Paul Eggert (2019-08-06):
+# Today Raymond Kumar reported the Government of Fiji Gazette Supplement No. 27
+# (2019-08-02) said that Fiji observes DST "commencing at 2.00 am on
+# Sunday, 10 November 2019 and ending at 3.00 am on Sunday, 12 January 2020."
+# For now, guess DST from 02:00 the second Sunday in November to 03:00
+# the first Sunday on or after January 12. January transitions reportedly
# depend on when school terms start. Although the guess is ad hoc, it matches
-# transitions since late 2014 and seems more likely to match future
-# practice than guessing no DST.
+# transitions planned this year and seems more likely to match future practice
+# than guessing no DST.
+# From Michael Deckers (2019-08-06):
+# https://www.laws.gov.fj/LawsAsMade/downloadfile/848
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Fiji 1998 1999 - Nov Sun>=1 2:00 1:00 -
Rule Fiji 1999 2000 - Feb lastSun 3:00 0 -
Rule Fiji 2009 only - Nov 29 2:00 1:00 -
Rule Fiji 2010 only - Mar lastSun 3:00 0 -
Rule Fiji 2010 2013 - Oct Sun>=21 2:00 1:00 -
Rule Fiji 2011 only - Mar Sun>=1 3:00 0 -
Rule Fiji 2012 2013 - Jan Sun>=18 3:00 0 -
Rule Fiji 2014 only - Jan Sun>=18 2:00 0 -
-Rule Fiji 2014 max - Nov Sun>=1 2:00 1:00 -
-Rule Fiji 2015 max - Jan Sun>=13 3:00 0 -
+Rule Fiji 2014 2018 - Nov Sun>=1 2:00 1:00 -
+Rule Fiji 2015 max - Jan Sun>=12 3:00 0 -
+Rule Fiji 2019 max - Nov Sun>=8 2:00 1:00 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Fiji 11:55:44 - LMT 1915 Oct 26 # Suva
12:00 Fiji +12/+13
# French Polynesia
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Gambier -8:59:48 - LMT 1912 Oct # Rikitea
-9:00 - -09
Zone Pacific/Marquesas -9:18:00 - LMT 1912 Oct
-9:30 - -0930
Zone Pacific/Tahiti -9:58:16 - LMT 1912 Oct # Papeete
-10:00 - -10
# Clipperton (near North America) is administered from French Polynesia;
# it is uninhabited.
# Guam
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
# http://guamlegislature.com/Public_Laws_5th/PL05-025.pdf
# http://documents.guam.gov/wp-content/uploads/E.O.-59-7-Guam-Daylight-Savings-Time-May-6-1959.pdf
Rule Guam 1959 only - Jun 27 2:00 1:00 D
# http://documents.guam.gov/wp-content/uploads/E.O.-61-5-Revocation-of-Daylight-Saving-Time-and-Restoratio.pdf
Rule Guam 1961 only - Jan 29 2:00 0 S
# http://documents.guam.gov/wp-content/uploads/E.O.-67-13-Guam-Daylight-Savings-Time.pdf
Rule Guam 1967 only - Sep 1 2:00 1:00 D
# http://documents.guam.gov/wp-content/uploads/E.O.-69-2-Repeal-of-Guam-Daylight-Saving-Time.pdf
Rule Guam 1969 only - Jan 26 0:01 0 S
# http://documents.guam.gov/wp-content/uploads/E.O.-69-10-Guam-Daylight-Saving-Time.pdf
Rule Guam 1969 only - Jun 22 2:00 1:00 D
Rule Guam 1969 only - Aug 31 2:00 0 S
# http://documents.guam.gov/wp-content/uploads/E.O.-70-10-Guam-Daylight-Saving-Time.pdf
# http://documents.guam.gov/wp-content/uploads/E.O.-70-30-End-of-Guam-Daylight-Saving-Time.pdf
# http://documents.guam.gov/wp-content/uploads/E.O.-71-5-Guam-Daylight-Savings-Time.pdf
Rule Guam 1970 1971 - Apr lastSun 2:00 1:00 D
Rule Guam 1970 1971 - Sep Sun>=1 2:00 0 S
# http://documents.guam.gov/wp-content/uploads/E.O.-73-28.-Guam-Day-light-Saving-Time.pdf
Rule Guam 1973 only - Dec 16 2:00 1:00 D
# http://documents.guam.gov/wp-content/uploads/E.O.-74-7-Guam-Daylight-Savings-Time-Rescinded.pdf
Rule Guam 1974 only - Feb 24 2:00 0 S
# http://documents.guam.gov/wp-content/uploads/E.O.-76-13-Daylight-Savings-Time.pdf
Rule Guam 1976 only - May 26 2:00 1:00 D
# http://documents.guam.gov/wp-content/uploads/E.O.-76-25-Revocation-of-E.O.-76-13.pdf
Rule Guam 1976 only - Aug 22 2:01 0 S
# http://documents.guam.gov/wp-content/uploads/E.O.-77-4-Daylight-Savings-Time.pdf
Rule Guam 1977 only - Apr 24 2:00 1:00 D
# http://documents.guam.gov/wp-content/uploads/E.O.-77-18-Guam-Standard-Time.pdf
Rule Guam 1977 only - Aug 28 2:00 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Guam -14:21:00 - LMT 1844 Dec 31
9:39:00 - LMT 1901 # Agana
10:00 - GST 1941 Dec 10 # Guam
9:00 - +09 1944 Jul 31
10:00 Guam G%sT 2000 Dec 23
10:00 - ChST # Chamorro Standard Time
Link Pacific/Guam Pacific/Saipan # N Mariana Is
# Kiribati
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Tarawa 11:32:04 - LMT 1901 # Bairiki
12:00 - +12
Zone Pacific/Enderbury -11:24:20 - LMT 1901
-12:00 - -12 1979 Oct
-11:00 - -11 1994 Dec 31
13:00 - +13
Zone Pacific/Kiritimati -10:29:20 - LMT 1901
-10:40 - -1040 1979 Oct
-10:00 - -10 1994 Dec 31
14:00 - +14
# N Mariana Is
# See Pacific/Guam.
# Marshall Is
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Majuro 11:24:48 - LMT 1901
11:00 - +11 1914 Oct
9:00 - +09 1919 Feb 1
11:00 - +11 1937
10:00 - +10 1941 Apr 1
9:00 - +09 1944 Jan 30
11:00 - +11 1969 Oct
12:00 - +12
Zone Pacific/Kwajalein 11:09:20 - LMT 1901
11:00 - +11 1937
10:00 - +10 1941 Apr 1
9:00 - +09 1944 Feb 6
11:00 - +11 1969 Oct
-12:00 - -12 1993 Aug 20 24:00
12:00 - +12
# Micronesia
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Chuuk -13:52:52 - LMT 1844 Dec 31
10:07:08 - LMT 1901
10:00 - +10 1914 Oct
9:00 - +09 1919 Feb 1
10:00 - +10 1941 Apr 1
9:00 - +09 1945 Aug
10:00 - +10
Zone Pacific/Pohnpei -13:27:08 - LMT 1844 Dec 31 # Kolonia
10:32:52 - LMT 1901
11:00 - +11 1914 Oct
9:00 - +09 1919 Feb 1
11:00 - +11 1937
10:00 - +10 1941 Apr 1
9:00 - +09 1945 Aug
11:00 - +11
Zone Pacific/Kosrae -13:08:04 - LMT 1844 Dec 31
10:51:56 - LMT 1901
11:00 - +11 1914 Oct
9:00 - +09 1919 Feb 1
11:00 - +11 1937
10:00 - +10 1941 Apr 1
9:00 - +09 1945 Aug
11:00 - +11 1969 Oct
12:00 - +12 1999
11:00 - +11
# Nauru
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Nauru 11:07:40 - LMT 1921 Jan 15 # Uaobe
11:30 - +1130 1942 Aug 29
9:00 - +09 1945 Sep 8
11:30 - +1130 1979 Feb 10 2:00
12:00 - +12
# New Caledonia
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule NC 1977 1978 - Dec Sun>=1 0:00 1:00 -
Rule NC 1978 1979 - Feb 27 0:00 0 -
Rule NC 1996 only - Dec 1 2:00s 1:00 -
# Shanks & Pottenger say the following was at 2:00; go with IATA.
Rule NC 1997 only - Mar 2 2:00s 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Noumea 11:05:48 - LMT 1912 Jan 13 # Nouméa
11:00 NC +11/+12
###############################################################################
# New Zealand
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule NZ 1927 only - Nov 6 2:00 1:00 S
Rule NZ 1928 only - Mar 4 2:00 0 M
Rule NZ 1928 1933 - Oct Sun>=8 2:00 0:30 S
Rule NZ 1929 1933 - Mar Sun>=15 2:00 0 M
Rule NZ 1934 1940 - Apr lastSun 2:00 0 M
Rule NZ 1934 1940 - Sep lastSun 2:00 0:30 S
Rule NZ 1946 only - Jan 1 0:00 0 S
# Since 1957 Chatham has been 45 minutes ahead of NZ, but until 2018a
# there was no documented single notation for the date and time of this
# transition. Duplicate the Rule lines for now, to give the 2018a change
# time to percolate out.
Rule NZ 1974 only - Nov Sun>=1 2:00s 1:00 D
Rule Chatham 1974 only - Nov Sun>=1 2:45s 1:00 -
Rule NZ 1975 only - Feb lastSun 2:00s 0 S
Rule Chatham 1975 only - Feb lastSun 2:45s 0 -
Rule NZ 1975 1988 - Oct lastSun 2:00s 1:00 D
Rule Chatham 1975 1988 - Oct lastSun 2:45s 1:00 -
Rule NZ 1976 1989 - Mar Sun>=1 2:00s 0 S
Rule Chatham 1976 1989 - Mar Sun>=1 2:45s 0 -
Rule NZ 1989 only - Oct Sun>=8 2:00s 1:00 D
Rule Chatham 1989 only - Oct Sun>=8 2:45s 1:00 -
Rule NZ 1990 2006 - Oct Sun>=1 2:00s 1:00 D
Rule Chatham 1990 2006 - Oct Sun>=1 2:45s 1:00 -
Rule NZ 1990 2007 - Mar Sun>=15 2:00s 0 S
Rule Chatham 1990 2007 - Mar Sun>=15 2:45s 0 -
Rule NZ 2007 max - Sep lastSun 2:00s 1:00 D
Rule Chatham 2007 max - Sep lastSun 2:45s 1:00 -
Rule NZ 2008 max - Apr Sun>=1 2:00s 0 S
Rule Chatham 2008 max - Apr Sun>=1 2:45s 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Auckland 11:39:04 - LMT 1868 Nov 2
11:30 NZ NZ%sT 1946 Jan 1
12:00 NZ NZ%sT
Zone Pacific/Chatham 12:13:48 - LMT 1868 Nov 2
12:15 - +1215 1946 Jan 1
12:45 Chatham +1245/+1345
Link Pacific/Auckland Antarctica/McMurdo
# Auckland Is
# uninhabited; Māori and Moriori, colonial settlers, pastoralists, sealers,
# and scientific personnel have wintered
# Campbell I
# minor whaling stations operated 1909/1914
# scientific station operated 1941/1995;
# previously whalers, sealers, pastoralists, and scientific personnel wintered
# was probably like Pacific/Auckland
# Cook Is
# From Shanks & Pottenger:
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Cook 1978 only - Nov 12 0:00 0:30 -
Rule Cook 1979 1991 - Mar Sun>=1 0:00 0 -
Rule Cook 1979 1990 - Oct lastSun 0:00 0:30 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Rarotonga -10:39:04 - LMT 1901 # Avarua
-10:30 - -1030 1978 Nov 12
-10:00 Cook -10/-0930
###############################################################################
# Niue
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Niue -11:19:40 - LMT 1901 # Alofi
-11:20 - -1120 1951
-11:30 - -1130 1978 Oct 1
-11:00 - -11
# Norfolk
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Norfolk 11:11:52 - LMT 1901 # Kingston
11:12 - +1112 1951
- 11:30 - +1130 1974 Oct 27 02:00
- 11:30 1:00 +1230 1975 Mar 2 02:00
- 11:30 - +1130 2015 Oct 4 02:00
- 11:00 - +11
+ 11:30 - +1130 1974 Oct 27 02:00s
+ 11:30 1:00 +1230 1975 Mar 2 02:00s
+ 11:30 - +1130 2015 Oct 4 02:00s
+ 11:00 - +11 2019 Jul
+ 11:00 AN +11/+12
# Palau (Belau)
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Palau -15:02:04 - LMT 1844 Dec 31 # Koror
8:57:56 - LMT 1901
9:00 - +09
# Papua New Guinea
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Port_Moresby 9:48:40 - LMT 1880
9:48:32 - PMMT 1895 # Port Moresby Mean Time
10:00 - +10
#
# From Paul Eggert (2014-10-13):
# Base the Bougainville entry on the Arawa-Kieta region, which appears to have
# the most people even though it was devastated in the Bougainville Civil War.
#
# Although Shanks gives 1942-03-15 / 1943-11-01 for UT +09, these dates
# are apparently rough guesswork from the starts of military campaigns.
# The World War II entries below are instead based on Arawa-Kieta.
# The Japanese occupied Kieta in July 1942,
# according to the Pacific War Online Encyclopedia
# https://pwencycl.kgbudge.com/B/o/Bougainville.htm
# and seem to have controlled it until their 1945-08-21 surrender.
#
# The Autonomous Region of Bougainville switched from UT +10 to +11
# on 2014-12-28 at 02:00. They call +11 "Bougainville Standard Time".
# See:
# http://www.bougainville24.com/bougainville-issues/bougainville-gets-own-timezone/
#
Zone Pacific/Bougainville 10:22:16 - LMT 1880
9:48:32 - PMMT 1895
10:00 - +10 1942 Jul
9:00 - +09 1945 Aug 21
10:00 - +10 2014 Dec 28 2:00
11:00 - +11
# Pitcairn
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Pitcairn -8:40:20 - LMT 1901 # Adamstown
-8:30 - -0830 1998 Apr 27 0:00
-8:00 - -08
# American Samoa
Zone Pacific/Pago_Pago 12:37:12 - LMT 1892 Jul 5
-11:22:48 - LMT 1911
-11:00 - SST # S=Samoa
Link Pacific/Pago_Pago Pacific/Midway # in US minor outlying islands
# Samoa (formerly and also known as Western Samoa)
# From Steffen Thorsen (2009-10-16):
# We have been in contact with the government of Samoa again, and received
# the following info:
#
# "Cabinet has now approved Daylight Saving to be effected next year
# commencing from the last Sunday of September 2010 and conclude first
# Sunday of April 2011."
#
# Background info:
# https://www.timeanddate.com/news/time/samoa-dst-plan-2009.html
#
# Samoa's Daylight Saving Time Act 2009 is available here, but does not
# contain any dates:
# http://www.parliament.gov.ws/documents/acts/Daylight%20Saving%20Act%20%202009%20%28English%29%20-%20Final%207-7-091.pdf
# From Laupue Raymond Hughes (2010-10-07):
# Please see
# http://www.mcil.gov.ws
# the Ministry of Commerce, Industry and Labour (sideframe) "Last Sunday
# September 2010 (26/09/10) - adjust clocks forward from 12:00 midnight
# to 01:00am and First Sunday April 2011 (03/04/11) - adjust clocks
# backwards from 1:00am to 12:00am"
# From Laupue Raymond Hughes (2011-03-07):
# [http://www.mcil.gov.ws/ftcd/daylight_saving_2011.pdf]
#
# ... when the standard time strikes the hour of four o'clock (4.00am
# or 0400 Hours) on the 2nd April 2011, then all instruments used to
# measure standard time are to be adjusted/changed to three o'clock
# (3:00am or 0300Hrs).
# From David Zülke (2011-05-09):
# Subject: Samoa to move timezone from east to west of international date line
#
# http://www.morningstar.co.uk/uk/markets/newsfeeditem.aspx?id=138501958347963
# From Paul Eggert (2014-06-27):
# The International Date Line Act 2011
# http://www.parliament.gov.ws/images/ACTS/International_Date_Line_Act__2011_-_Eng.pdf
# changed Samoa from UT -11 to +13, effective "12 o'clock midnight, on
# Thursday 29th December 2011". The International Date Line was adjusted
# accordingly.
# From Laupue Raymond Hughes (2011-09-02):
# http://www.mcil.gov.ws/mcil_publications.html
#
# here is the official website publication for Samoa DST and dateline change
#
# DST
# Year End Time Start Time
# 2011 - - - - - - 24 September 3:00am to 4:00am
# 2012 01 April 4:00am to 3:00am - - - - - -
#
# Dateline Change skip Friday 30th Dec 2011
# Thursday 29th December 2011 23:59:59 Hours
# Saturday 31st December 2011 00:00:00 Hours
#
# From Nicholas Pereira (2012-09-10):
# Daylight Saving Time commences on Sunday 30th September 2012 and
# ends on Sunday 7th of April 2013....
# http://www.mcil.gov.ws/mcil_publications.html
#
# From Paul Eggert (2014-07-08):
# That web page currently lists transitions for 2012/3 and 2013/4.
# Assume the pattern instituted in 2012 will continue indefinitely.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule WS 2010 only - Sep lastSun 0:00 1 -
Rule WS 2011 only - Apr Sat>=1 4:00 0 -
Rule WS 2011 only - Sep lastSat 3:00 1 -
Rule WS 2012 max - Apr Sun>=1 4:00 0 -
Rule WS 2012 max - Sep lastSun 3:00 1 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Apia 12:33:04 - LMT 1892 Jul 5
-11:26:56 - LMT 1911
-11:30 - -1130 1950
-11:00 WS -11/-10 2011 Dec 29 24:00
13:00 WS +13/+14
# Solomon Is
# excludes Bougainville, for which see Papua New Guinea
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Guadalcanal 10:39:48 - LMT 1912 Oct # Honiara
11:00 - +11
# Tokelau
#
# From Gwillim Law (2011-12-29)
# A correspondent informed me that Tokelau, like Samoa, will be skipping
# December 31 this year ...
#
# From Steffen Thorsen (2012-07-25)
# ... we double checked by calling hotels and offices based in Tokelau asking
# about the time there, and they all told a time that agrees with UTC+13....
# Shanks says UT-10 from 1901 [but] ... there is a good chance the change
# actually was to UT-11 back then.
#
# From Paul Eggert (2012-07-25)
# A Google Books snippet of Appendix to the Journals of the House of
# Representatives of New Zealand, Session 1948,
# <https://books.google.com/books?id=ZaVCAQAAIAAJ>, page 65, says Tokelau
# was "11 hours slow on G.M.T." Go with Thorsen and assume Shanks & Pottenger
# are off by an hour starting in 1901.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Fakaofo -11:24:56 - LMT 1901
-11:00 - -11 2011 Dec 30
13:00 - +13
# Tonga
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Tonga 1999 only - Oct 7 2:00s 1:00 -
Rule Tonga 2000 only - Mar 19 2:00s 0 -
Rule Tonga 2000 2001 - Nov Sun>=1 2:00 1:00 -
Rule Tonga 2001 2002 - Jan lastSun 2:00 0 -
Rule Tonga 2016 only - Nov Sun>=1 2:00 1:00 -
Rule Tonga 2017 only - Jan Sun>=15 3:00 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Tongatapu 12:19:20 - LMT 1901
12:20 - +1220 1941
13:00 - +13 1999
13:00 Tonga +13/+14
# Tuvalu
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Funafuti 11:56:52 - LMT 1901
12:00 - +12
# US minor outlying islands
# Howland, Baker
# Howland was mined for guano by American companies 1857-1878 and British
# 1886-1891; Baker was similar but exact dates are not known.
# Inhabited by civilians 1935-1942; U.S. military bases 1943-1944;
# uninhabited thereafter.
# Howland observed Hawaii Standard Time (UT -10:30) in 1937;
# see page 206 of Elgen M. Long and Marie K. Long,
# Amelia Earhart: the Mystery Solved, Simon & Schuster (2000).
# So most likely Howland and Baker observed Hawaii Time from 1935
# until they were abandoned after the war.
# Jarvis
# Mined for guano by American companies 1857-1879 and British 1883?-1891?.
# Inhabited by civilians 1935-1942; IGY scientific base 1957-1958;
# uninhabited thereafter.
# no information; was probably like Pacific/Kiritimati
# Johnston
#
# From Paul Eggert (2017-02-10):
# Sometimes Johnston kept Hawaii time, and sometimes it was an hour behind.
# Details are uncertain. We have no data for Johnston after 1970, so
# treat it like Hawaii for now. Since Johnston is now uninhabited,
# its link to Pacific/Honolulu is in the 'backward' file.
#
# In his memoirs of June 6th to October 4, 1945
# <http://www.315bw.org/Herb_Bach.htm> (2005), Herbert C. Bach writes,
# "We started our letdown to Kwajalein Atoll and landed there at 5:00 AM
# Johnston time, 1:30 AM Kwajalein time." This was in June 1945, and
# confirms that Johnston kept the same time as Honolulu in summer 1945.
#
# From Lyle McElhaney (2014-03-11):
# [W]hen JI was being used for that [atomic bomb] testing, the time being used
# was not Hawaiian time but rather the same time being used on the ships,
# which had a GMT offset of -11 hours. This apparently applied to at least the
# time from Operation Newsreel (Hardtack I/Teak shot, 1958-08-01) to the last
# Operation Fishbowl shot (Tightrope, 1962-11-04).... [See] Herman Hoerlin,
# "The United States High-Altitude Test Experience: A Review Emphasizing the
# Impact on the Environment", Los Alamos LA-6405, Oct 1976.
# https://www.fas.org/sgp/othergov/doe/lanl/docs1/00322994.pdf
# See the table on page 4 where he lists GMT and local times for the tests; a
# footnote for the JI tests reads that local time is "JI time = Hawaii Time
# Minus One Hour".
# Kingman
# uninhabited
# Midway
# See Pacific/Pago_Pago.
# Palmyra
# uninhabited since World War II; was probably like Pacific/Kiritimati
# Wake
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Wake 11:06:28 - LMT 1901
12:00 - +12
# Vanuatu
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Vanuatu 1983 only - Sep 25 0:00 1:00 -
Rule Vanuatu 1984 1991 - Mar Sun>=23 0:00 0 -
Rule Vanuatu 1984 only - Oct 23 0:00 1:00 -
Rule Vanuatu 1985 1991 - Sep Sun>=23 0:00 1:00 -
Rule Vanuatu 1992 1993 - Jan Sun>=23 0:00 0 -
Rule Vanuatu 1992 only - Oct Sun>=23 0:00 1:00 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Efate 11:13:16 - LMT 1912 Jan 13 # Vila
11:00 Vanuatu +11/+12
# Wallis and Futuna
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Wallis 12:15:20 - LMT 1901
12:00 - +12
###############################################################################
# NOTES
# This file is by no means authoritative; if you think you know better,
# go ahead and edit the file (and please send any changes to
# tz@iana.org for general use in the future). For more, please see
# the file CONTRIBUTING in the tz distribution.
# From Paul Eggert (2018-11-18):
#
# Unless otherwise specified, the source for data through 1990 is:
# Thomas G. Shanks and Rique Pottenger, The International Atlas (6th edition),
# San Diego: ACS Publications, Inc. (2003).
# Unfortunately this book contains many errors and cites no sources.
#
# Many years ago Gwillim Law wrote that a good source
# for time zone data was the International Air Transport
# Association's Standard Schedules Information Manual (IATA SSIM),
# published semiannually. Law sent in several helpful summaries
# of the IATA's data after 1990. Except where otherwise noted,
# IATA SSIM is the source for entries after 1990.
#
# Another source occasionally used is Edward W. Whitman, World Time Differences,
# Whitman Publishing Co, 2 Niagara Av, Ealing, London (undated), which
# I found in the UCLA library.
#
# For data circa 1899, a common source is:
# Milne J. Civil time. Geogr J. 1899 Feb;13(2):173-94.
# https://www.jstor.org/stable/1774359
#
# A reliable and entertaining source about time zones is
# Derek Howse, Greenwich time and longitude, Philip Wilson Publishers (1997).
#
# I invented the abbreviation marked "*".
# The following abbreviations are from other sources.
# Corrections are welcome!
# std dst
# LMT Local Mean Time
# 8:00 AWST AWDT Western Australia
# 9:30 ACST ACDT Central Australia
# 10:00 AEST AEDT Eastern Australia
# 10:00 GST GDT* Guam through 2000
# 10:00 ChST Chamorro
# 11:30 NZMT NZST New Zealand through 1945
# 12:00 NZST NZDT New Zealand 1946-present
# -11:00 SST Samoa
# -10:00 HST Hawaii
#
# See the 'northamerica' file for Hawaii.
# See the 'southamerica' file for Easter I and the Galápagos Is.
###############################################################################
# Australia
# From Paul Eggert (2014-06-30):
# Daylight saving time has long been controversial in Australia, pitting
# region against region, rural against urban, and local against global.
# For example, in her review of Graeme Davison's _The Unforgiving
# Minute: how Australians learned to tell the time_ (1993), Perth native
# Phillipa J Martyr wrote, "The section entitled 'Saving Daylight' was
# very informative, but was (as can, sadly, only be expected from a
# Melbourne-based study) replete with the usual chuckleheaded
# Queenslanders and straw-chewing yokels from the West prattling fables
# about fading curtains and crazed farm animals."
# Electronic Journal of Australian and New Zealand History (1997-03-03)
# http://www.jcu.edu.au/aff/history/reviews/davison.htm
# From Paul Eggert (2005-12-08):
# Implementation Dates of Daylight Saving Time within Australia
# http://www.bom.gov.au/climate/averages/tables/dst_times.shtml
# summarizes daylight saving issues in Australia.
# From Arthur David Olson (2005-12-12):
# Lawlink NSW:Daylight Saving in New South Wales
# http://www.lawlink.nsw.gov.au/lawlink/Corporate/ll_agdinfo.nsf/pages/community_relations_daylight_saving
# covers New South Wales in particular.
# From John Mackin (1991-03-06):
# We in Australia have _never_ referred to DST as 'daylight' time.
# It is called 'summer' time. Now by a happy coincidence, 'summer'
# and 'standard' happen to start with the same letter; hence, the
# abbreviation does _not_ change...
# The legislation does not actually define abbreviations, at least
# in this State, but the abbreviation is just commonly taken to be the
# initials of the phrase, and the legislation here uniformly uses
# the phrase 'summer time' and does not use the phrase 'daylight
# time'.
# Announcers on the Commonwealth radio network, the ABC (for Australian
# Broadcasting Commission), use the phrases 'Eastern Standard Time'
# or 'Eastern Summer Time'. (Note, though, that as I say in the
# current australasia file, there is really no such thing.) Announcers
# on its overseas service, Radio Australia, use the same phrases
# prefixed by the word 'Australian' when referring to local times;
# time announcements on that service, naturally enough, are made in UTC.
# From Paul Eggert (2014-06-30):
#
# Inspired by Mackin's remarks quoted above, earlier versions of this
# file used "EST" for both Eastern Standard Time and Eastern Summer
# Time in Australia, and similarly for "CST", "CWST", and "WST".
# However, these abbreviations were confusing and were not common
# practice among Australians, and there were justifiable complaints
# about them, so I attempted to survey current Australian usage.
# For the tz database, the full English phrase is not that important;
# what matters is the abbreviation. It's difficult to survey the web
# directly for abbreviation usage, as there are so many false hits for
# strings like "EST" and "EDT", so I looked for pages that defined an
# abbreviation for eastern or central DST in Australia, and got the
# following numbers of unique hits for the listed Google queries:
#
# 10 "Eastern Daylight Time AEST" site:au [some are false hits]
# 10 "Eastern Summer Time AEST" site:au
# 10 "Summer Time AEDT" site:au
# 13 "EDST Eastern Daylight Saving Time" site:au
# 18 "Summer Time ESST" site:au
# 28 "Eastern Daylight Saving Time EDST" site:au
# 39 "EDT Eastern Daylight Time" site:au [some are false hits]
# 53 "Eastern Daylight Time EDT" site:au [some are false hits]
# 54 "AEDT Australian Eastern Daylight Time" site:au
# 182 "Eastern Daylight Time AEDT" site:au
#
# 17 "Central Daylight Time CDT" site:au [some are false hits]
# 46 "Central Daylight Time ACDT" site:au
#
# I tried several other variants (e.g., "Eastern Summer Time EST") but
# they all returned fewer than 10 unique hits. I also looked for pages
# mentioning both "western standard time" and an abbreviation, since
# there is no WST in the US to generate false hits, and found:
#
# 156 "western standard time" AWST site:au
# 226 "western standard time" WST site:au
#
# I then surveyed the top ten newspapers in Australia by circulation as
# listed in Wikipedia, using Google queries like "AEDT site:heraldsun.com.au"
# and obtaining estimated counts from the initial page of search results.
# All ten papers greatly preferred "AEDT" to "EDT". The papers
# surveyed were the Herald Sun, The Daily Telegraph, The Courier-Mail,
# The Sydney Morning Herald, The West Australian, The Age, The Advertiser,
# The Australian, The Financial Review, and The Herald (Newcastle).
#
# I also searched for historical usage, to see whether abbreviations
# like "AEDT" are new. A Trove search <http://trove.nla.gov.au/>
# found only one newspaper (The Canberra Times) with a house style
# dating back to the 1970s, I expect because other newspapers weren't
# fully indexed. The Canberra Times strongly preferred abbreviations
# like "AEDT". The first occurrence of "AEDT" was a World Weather
# column (1971-11-17, page 24), and of "ACDT" was a Scoreboard column
# (1993-01-24, p 16). The style was the typical usage but was not
# strictly enforced; for example, "Welcome to the twilight zones ..."
# (1994-10-29, p 1) uses the abbreviations AEST/AEDT, CST/CDT, and
# WST, and goes on to say, "The confusion and frustration some feel
# about the lack of uniformity among Australia's six states and two
# territories has prompted one group to form its very own political
# party -- the Sydney-based Daylight Saving Extension Party."
#
# I also surveyed federal government sources. They did not agree:
#
# The Australian Government (2014-03-26)
# http://australia.gov.au/about-australia/our-country/time
# (This document was produced by the Department of Finance.)
# AEST ACST AWST AEDT ACDT
#
# Bureau of Meteorology (2012-11-08)
# http://www.bom.gov.au/climate/averages/tables/daysavtm.shtml
# EST CST WST EDT CDT
#
# Civil Aviation Safety Authority (undated)
# http://services.casa.gov.au/outnback/inc/pages/episode3/episode-3_time_zones.shtml
# EST CST WST (no abbreviations given for DST)
#
# Geoscience Australia (2011-11-24)
# http://www.ga.gov.au/geodesy/astro/sunrise.jsp
# AEST ACST AWST AEDT ACDT
#
# Parliamentary Library (2008-11-10)
# https://www.aph.gov.au/binaries/library/pubs/rp/2008-09/09rp14.pdf
# EST CST WST preferred for standard time; AEST AEDT ACST ACDT also used
#
# The Transport Safety Bureau has an extensive series of accident reports,
# and investigators seem to use whatever abbreviation they like.
# Googling site:atsb.gov.au found the following number of unique hits:
# 311 "ESuT", 195 "EDT", 26 "AEDT", 83 "CSuT", 46 "CDT".
# "_SuT" tended to appear in older reports, and "A_DT" tended to
# appear in reports of events with international implications.
#
# From the above it appears that there is a working consensus in
# Australia to use trailing "DT" for daylight saving time; although
# some sources use trailing "SST" or "ST" or "SuT" they are by far in
# the minority. The case for leading "A" is weaker, but since it
# seems to be preferred in the overall web and is preferred in all
# the leading newspaper websites and in many government departments,
# it has a stronger case than omitting the leading "A". The current
# version of the database therefore uses abbreviations like "AEST" and
# "AEDT" for Australian time zones.
# From Paul Eggert (1995-12-19):
# Shanks & Pottenger report 2:00 for all autumn changes in Australia and NZ.
# Mark Prior writes that his newspaper
# reports that NSW's fall 1995 change will occur at 2:00,
# but Robert Elz says it's been 3:00 in Victoria since 1970
# and perhaps the newspaper's '2:00' is referring to standard time.
# For now we'll continue to assume 2:00s for changes since 1960.
# From Eric Ulevik (1998-01-05):
#
# Here are some URLs to Australian time legislation. These URLs are stable,
# and should probably be included in the data file. There are probably more
# relevant entries in this database.
#
# NSW (including LHI and Broken Hill):
# Standard Time Act 1987 (updated 1995-04-04)
# https://www.austlii.edu.au/au/legis/nsw/consol_act/sta1987137/index.html
# ACT
# Standard Time and Summer Time Act 1972
# https://www.austlii.edu.au/au/legis/act/consol_act/stasta1972279/index.html
# SA
# Standard Time Act, 1898
# https://www.austlii.edu.au/au/legis/sa/consol_act/sta1898137/index.html
# From David Grosz (2005-06-13):
# It was announced last week that Daylight Saving would be extended by
# one week next year to allow for the 2006 Commonwealth Games.
# Daylight Saving is now to end for next year only on the first Sunday
# in April instead of the last Sunday in March.
#
# From Gwillim Law (2005-06-14):
# I did some Googling and found that all of those states (and territory) plan
# to extend DST together in 2006.
# ACT: http://www.cmd.act.gov.au/mediareleases/fileread.cfm?file=86.txt
# New South Wales: http://www.thecouriermail.news.com.au/common/story_page/0,5936,15538869%255E1702,00.html
# South Australia: http://www.news.com.au/story/0,10117,15555031-1246,00.html
# Tasmania: http://www.media.tas.gov.au/release.php?id=14772
# Victoria: I wasn't able to find anything separate, but the other articles
# allude to it.
# But not Queensland
# http://www.news.com.au/story/0,10117,15564030-1248,00.html
# Northern Territory
# From George Shepherd via Simon Woodhead via Robert Elz (1991-03-06):
# # The NORTHERN TERRITORY.. [ Courtesy N.T. Dept of the Chief Minister ]
# # [ Nov 1990 ]
# # N.T. have never utilised any DST due to sub-tropical/tropical location.
# ...
# Zone Australia/North 9:30 - CST
# From Bradley White (1991-03-04):
# A recent excerpt from an Australian newspaper...
# the Northern Territory do[es] not have daylight saving.
# Western Australia
# From George Shepherd via Simon Woodhead via Robert Elz (1991-03-06):
# # The state of WESTERN AUSTRALIA.. [ Courtesy W.A. dept Premier+Cabinet ]
# # [ Nov 1990 ]
# # W.A. suffers from a great deal of public and political opposition to
# # DST in principle. A bill is brought before parliament in most years, but
# # usually defeated either in the upper house, or in party caucus
# # before reaching parliament.
# ...
# Zone Australia/West 8:00 AW %sST
# ...
# Rule AW 1974 only - Oct lastSun 2:00 1:00 D
# Rule AW 1975 only - Mar Sun>=1 3:00 0 W
# Rule AW 1983 only - Oct lastSun 2:00 1:00 D
# Rule AW 1984 only - Mar Sun>=1 3:00 0 W
# From Bradley White (1991-03-04):
# A recent excerpt from an Australian newspaper...
# Western Australia...do[es] not have daylight saving.
# From John D. Newman via Bradley White (1991-11-02):
# Western Australia is still on "winter time". Some DH in Sydney
# rang me at home a few days ago at 6.00am. (He had just arrived at
# work at 9.00am.)
# W.A. is switching to Summer Time on Nov 17th just to confuse
# everybody again.
# From Arthur David Olson (1992-03-08):
# The 1992 ending date used in the rules is a best guess;
# it matches what was used in the past.
# The Australian Bureau of Meteorology FAQ
# http://www.bom.gov.au/faq/faqgen.htm
# (1999-09-27) writes that Giles Meteorological Station uses
# South Australian time even though it's located in Western Australia.
# From Paul Eggert (2018-04-01):
# The Guardian Express of Perth, Australia reported today that the
# government decided to advance the clocks permanently on January 1,
# 2019, from UT +08 to UT +09. The article noted that an exemption
# would be made for people aged 61 and over, who "can apply in writing
# to have the extra hour of sunshine removed from their area." See:
# Daylight saving coming to WA in 2019. Guardian Express. 2018-04-01.
# https://www.communitynews.com.au/guardian-express/news/exclusive-daylight-savings-coming-wa-summer-2018/
# Queensland
# From Paul Eggert (2018-02-26):
# I lack access to the following source for Queensland DST:
# Pearce C. History of daylight saving time in Queensland.
# Queensland Hist J. 2017 Aug;23(6):389-403
# https://search.informit.com.au/documentSummary;dn=994682348436426;res=IELHSS
# From George Shepherd via Simon Woodhead via Robert Elz (1991-03-06):
# # The state of QUEENSLAND.. [ Courtesy Qld. Dept Premier Econ&Trade Devel ]
# # [ Dec 1990 ]
# ...
# Zone Australia/Queensland 10:00 AQ %sST
# ...
# Rule AQ 1971 only - Oct lastSun 2:00 1:00 D
# Rule AQ 1972 only - Feb lastSun 3:00 0 E
# Rule AQ 1989 max - Oct lastSun 2:00 1:00 D
# Rule AQ 1990 max - Mar Sun>=1 3:00 0 E
# From Bradley White (1989-12-24):
# "Australia/Queensland" now observes daylight time (i.e. from
# October 1989).
# From Bradley White (1991-03-04):
# A recent excerpt from an Australian newspaper...
# ...Queensland...[has] agreed to end daylight saving
# at 3am tomorrow (March 3)...
# From John Mackin (1991-03-06):
# I can certainly confirm for my part that Daylight Saving in NSW did in fact
# end on Sunday, 3 March. I don't know at what hour, though. (It surprised
# me.)
# From Bradley White (1992-03-08):
# ...there was recently a referendum in Queensland which resulted
# in the experimental daylight saving system being abandoned. So, ...
# ...
# Rule QLD 1989 1991 - Oct lastSun 2:00 1:00 D
# Rule QLD 1990 1992 - Mar Sun>=1 3:00 0 S
# ...
# From Arthur David Olson (1992-03-08):
# The chosen rules the union of the 1971/1972 change and the 1989-1992 changes.
# From Christopher Hunt (2006-11-21), after an advance warning
# from Jesper Nørgaard Welen (2006-11-01):
# WA are trialing DST for three years.
# http://www.parliament.wa.gov.au/parliament/bills.nsf/9A1B183144403DA54825721200088DF1/$File/Bill175-1B.pdf
# From Rives McDow (2002-04-09):
# The most interesting region I have found consists of three towns on the
# southern coast.... South Australia observes daylight saving time; Western
# Australia does not. The two states are one and a half hours apart. The
# residents decided to forget about this nonsense of changing the clock so
# much and set the local time 20 hours and 45 minutes from the
# international date line, or right in the middle of the time of South
# Australia and Western Australia....
#
# From Paul Eggert (2002-04-09):
# This is confirmed by the section entitled
# "What's the deal with time zones???" in
# http://www.earthsci.unimelb.edu.au/~awatkins/null.html
#
# From Alex Livingston (2006-12-07):
# ... it was just on four years ago that I drove along the Eyre Highway,
# which passes through eastern Western Australia close to the southern
# coast of the continent.
#
# I paid particular attention to the time kept there. There can be no
# dispute that UTC+08:45 was considered "the time" from the border
# village just inside the border with South Australia to as far west
# as just east of Caiguna. There can also be no dispute that Eucla is
# the largest population centre in this zone....
#
# Now that Western Australia is observing daylight saving, the
# question arose whether this part of the state would follow suit. I
# just called the border village and confirmed that indeed they have,
# meaning that they are now observing UTC+09:45.
#
# (2006-12-09):
# I personally doubt that either experimentation with daylight saving
# in WA or its introduction in SA had anything to do with the genesis
# of this time zone. My hunch is that it's been around since well
# before 1975. I remember seeing it noted on road maps decades ago.
#
# From Gilmore Davidson (2019-04-08):
# https://www.abc.net.au/news/2019-04-08/this-remote-stretch-of-desert-has-its-own-custom-time-zone/10981000
# ... include[s] a rough description of the geographical boundaries...
# "The time zone exists for about 340 kilometres and takes in the tiny
# roadhouse communities of Cocklebiddy, Madura, Eucla and Border Village."
# ... and an indication that the zone has definitely been in existence
# since before the 1970 cut-off of the database ...
# From Paul Eggert (2019-05-17):
# That ABC Esperance story by Christien de Garis also says:
# Although the Central Western Time Zone is not officially recognised (your
# phones won't automatically change), there is a sign instructing you which
# way to wind your clocks 45 minutes and scrawled underneath one of them in
# Texta is the word: 'Why'?
# "Good question," Mr Pike said.
# "I don't even know that, and it's been going for over 50 years."
# From Paul Eggert (2006-12-15):
# For lack of better info, assume the tradition dates back to the
# introduction of standard time in 1895.
# southeast Australia
#
# From Paul Eggert (2007-07-23):
# Starting autumn 2008 Victoria, NSW, South Australia, Tasmania and the ACT
# end DST the first Sunday in April and start DST the first Sunday in October.
# http://www.theage.com.au/news/national/daylight-savings-to-span-six-months/2007/06/27/1182623966703.html
# South Australia
# From Bradley White (1991-03-04):
# A recent excerpt from an Australian newspaper...
# ...South Australia...[has] agreed to end daylight saving
# at 3am tomorrow (March 3)...
# From George Shepherd via Simon Woodhead via Robert Elz (1991-03-06):
# # The state of SOUTH AUSTRALIA....[ Courtesy of S.A. Dept of Labour ]
# # [ Nov 1990 ]
# ...
# Zone Australia/South 9:30 AS %sST
# ...
# Rule AS 1971 max - Oct lastSun 2:00 1:00 D
# Rule AS 1972 1985 - Mar Sun>=1 3:00 0 C
# Rule AS 1986 1990 - Mar Sun>=15 3:00 0 C
# Rule AS 1991 max - Mar Sun>=1 3:00 0 C
# From Bradley White (1992-03-11):
# Recent correspondence with a friend in Adelaide
# contained the following exchange: "Due to the Adelaide Festival,
# South Australia delays setting back our clocks for a few weeks."
# From Robert Elz (1992-03-13):
# I heard that apparently (or at least, it appears that)
# South Aus will have an extra 3 weeks daylight saving every even
# numbered year (from 1990). That's when the Adelaide Festival
# is on...
# From Robert Elz (1992-03-16, 00:57:07 +1000):
# DST didn't end in Adelaide today (yesterday)....
# But whether it's "4th Sunday" or "2nd last Sunday" I have no idea whatever...
# (it's just as likely to be "the Sunday we pick for this year"...).
# From Bradley White (1994-04-11):
# If Sun, 15 March, 1992 was at +1030 as kre asserts, but yet Sun, 20 March,
# 1994 was at +0930 as John Connolly's customer seems to assert, then I can
# only conclude that the actual rule is more complicated....
# From John Warburton (1994-10-07):
# The new Daylight Savings dates for South Australia ...
# was gazetted in the Government Hansard on Sep 26 1994....
# start on last Sunday in October and end in last sunday in March.
# From Paul Eggert (2007-07-23):
# See "southeast Australia" above for 2008 and later.
# Tasmania
# The rules for 1967 through 1991 were reported by George Shepherd
# via Simon Woodhead via Robert Elz (1991-03-06):
# # The state of TASMANIA.. [Courtesy Tasmanian Dept of Premier + Cabinet ]
# # [ Nov 1990 ]
# From Bill Hart via Guy Harris (1991-10-10):
# Oh yes, the new daylight savings rules are uniquely tasmanian, we have
# 6 weeks a year now when we are out of sync with the rest of Australia
# (but nothing new about that).
# From Alex Livingston (1999-10-04):
# I heard on the ABC (Australian Broadcasting Corporation) radio news on the
# (long) weekend that Tasmania, which usually goes its own way in this regard,
# has decided to join with most of NSW, the ACT, and most of Victoria
# (Australia) and start daylight saving on the last Sunday in August in 2000
# instead of the first Sunday in October.
# Sim Alam (2000-07-03) reported a legal citation for the 2000/2001 rules:
# http://www.thelaw.tas.gov.au/fragview/42++1968+GS3A@EN+2000070300
# From Paul Eggert (2007-07-23):
# See "southeast Australia" above for 2008 and later.
# Victoria
# The rules for 1971 through 1991 were reported by George Shepherd
# via Simon Woodhead via Robert Elz (1991-03-06):
# # The state of VICTORIA.. [ Courtesy of Vic. Dept of Premier + Cabinet ]
# # [ Nov 1990 ]
# From Scott Harrington (2001-08-29):
# On KQED's "City Arts and Lectures" program last night I heard an
# interesting story about daylight savings time. Dr. John Heilbron was
# discussing his book "The Sun in the Church: Cathedrals as Solar
# Observatories"[1], and in particular the Shrine of Remembrance[2] located
# in Melbourne, Australia.
#
# Apparently the shrine's main purpose is a beam of sunlight which
# illuminates a special spot on the floor at the 11th hour of the 11th day
# of the 11th month (Remembrance Day) every year in memory of Australia's
# fallen WWI soldiers. And if you go there on Nov. 11, at 11am local time,
# you will indeed see the sunbeam illuminate the special spot at the
# expected time.
#
# However, that is only because of some special mirror contraption that had
# to be employed, since due to daylight savings time, the true solar time of
# the remembrance moment occurs one hour later (or earlier?). Perhaps
# someone with more information on this jury-rig can tell us more.
#
# [1] http://www.hup.harvard.edu/catalog/HEISUN.html
# [2] http://www.shrine.org.au
# From Paul Eggert (2007-07-23):
# See "southeast Australia" above for 2008 and later.
# New South Wales
# From Arthur David Olson:
# New South Wales and subjurisdictions have their own ideas of a fun time.
# Based on law library research by John Mackin,
# who notes:
# In Australia, time is not legislated federally, but rather by the
# individual states. Thus, while such terms as "Eastern Standard Time"
# [I mean, of course, Australian EST, not any other kind] are in common
# use, _they have NO REAL MEANING_, as they are not defined in the
# legislation. This is very important to understand.
# I have researched New South Wales time only...
# From Eric Ulevik (1999-05-26):
# DST will start in NSW on the last Sunday of August, rather than the usual
# October in 2000. See: Matthew Moore,
# Two months more daylight saving, Sydney Morning Herald (1999-05-26).
# http://www.smh.com.au/news/9905/26/pageone/pageone4.html
# From Paul Eggert (1999-09-27):
# See the following official NSW source:
# Daylight Saving in New South Wales.
# http://dir.gis.nsw.gov.au/cgi-bin/genobject/document/other/daylightsaving/tigGmZ
#
# Narrabri Shire (NSW) council has announced it will ignore the extension of
# daylight saving next year. See:
# Narrabri Council to ignore daylight saving
# http://abc.net.au/news/regionals/neweng/monthly/regeng-22jul1999-1.htm
# (1999-07-22). For now, we'll wait to see if this really happens.
#
# Victoria will follow NSW. See:
# Vic to extend daylight saving (1999-07-28)
# http://abc.net.au/local/news/olympics/1999/07/item19990728112314_1.htm
#
# However, South Australia rejected the DST request. See:
# South Australia rejects Olympics daylight savings request (1999-07-19)
# http://abc.net.au/news/olympics/1999/07/item19990719151754_1.htm
#
# Queensland also will not observe DST for the Olympics. See:
# Qld says no to daylight savings for Olympics
# http://abc.net.au/news/olympics/1999/06/item19990601114608_1.htm
# (1999-06-01), which quotes Queensland Premier Peter Beattie as saying
# "Look you've got to remember in my family when this came up last time
# I voted for it, my wife voted against it and she said to me it's all very
# well for you, you don't have to worry about getting the children out of
# bed, getting them to school, getting them to sleep at night.
# I've been through all this argument domestically...my wife rules."
#
# Broken Hill will stick with South Australian time in 2000. See:
# Broken Hill to be behind the times (1999-07-21)
# http://abc.net.au/news/regionals/brokenh/monthly/regbrok-21jul1999-6.htm
# IATA SSIM (1998-09) says that the spring 2000 change for Australian
# Capital Territory, New South Wales except Lord Howe Island and Broken
# Hill, and Victoria will be August 27, presumably due to the Sydney Olympics.
# From Eric Ulevik, referring to Sydney's Sun Herald (2000-08-13), page 29:
# The Queensland Premier Peter Beattie is encouraging northern NSW
# towns to use Queensland time.
# From Paul Eggert (2007-07-23):
# See "southeast Australia" above for 2008 and later.
# Yancowinna
# From John Mackin (1989-01-04):
# 'Broken Hill' means the County of Yancowinna.
# From George Shepherd via Simon Woodhead via Robert Elz (1991-03-06):
# # YANCOWINNA.. [ Confirmation courtesy of Broken Hill Postmaster ]
# # [ Dec 1990 ]
# ...
# # Yancowinna uses Central Standard Time, despite [its] location on the
# # New South Wales side of the S.A. border. Most business and social dealings
# # are with CST zones, therefore CST is legislated by local government
# # although the switch to Summer Time occurs in line with N.S.W. There have
# # been years when this did not apply, but the historical data is not
# # presently available.
# Zone Australia/Yancowinna 9:30 AY %sST
# ...
# Rule AY 1971 1985 - Oct lastSun 2:00 1:00 D
# Rule AY 1972 only - Feb lastSun 3:00 0 C
# [followed by other Rules]
# Lord Howe Island
# From George Shepherd via Simon Woodhead via Robert Elz (1991-03-06):
# LHI... [ Courtesy of Pauline Van Winsen ]
# [ Dec 1990 ]
# Lord Howe Island is located off the New South Wales coast, and is half an
# hour ahead of NSW time.
# From James Lonergan, Secretary, Lord Howe Island Board (2000-01-27):
# Lord Howe Island summer time in 2000/2001 will commence on the same
# date as the rest of NSW (i.e. 2000-08-27). For your information the
# Lord Howe Island Board (controlling authority for the Island) is
# seeking the community's views on various options for summer time
# arrangements on the Island, e.g. advance clocks by 1 full hour
# instead of only 30 minutes. [Dependent] on the wishes of residents
# the Board may approach the NSW government to change the existing
# arrangements. The starting date for summer time on the Island will
# however always coincide with the rest of NSW.
# From James Lonergan, Secretary, Lord Howe Island Board (2000-10-25):
# Lord Howe Island advances clocks by 30 minutes during DST in NSW and retards
# clocks by 30 minutes when DST finishes. Since DST was most recently
# introduced in NSW, the "changeover" time on the Island has been 02:00 as
# shown on clocks on LHI. I guess this means that for 30 minutes at the start
# of DST, LHI is actually 1 hour ahead of the rest of NSW.
# From Paul Eggert (2006-03-22):
# For Lord Howe dates we use Shanks & Pottenger through 1989, and
# Lonergan thereafter. For times we use Lonergan.
# From Paul Eggert (2007-07-23):
# See "southeast Australia" above for 2008 and later.
# From Steffen Thorsen (2009-04-28):
# According to the official press release, South Australia's extended daylight
# saving period will continue with the same rules as used during the 2008-2009
# summer (southern hemisphere).
#
# From
# http://www.safework.sa.gov.au/uploaded_files/DaylightDatesSet.pdf
# The extended daylight saving period that South Australia has been trialling
# for over the last year is now set to be ongoing.
# Daylight saving will continue to start on the first Sunday in October each
# year and finish on the first Sunday in April the following year.
# Industrial Relations Minister, Paul Caica, says this provides South Australia
# with a consistent half hour time difference with NSW, Victoria, Tasmania and
# the ACT for all 52 weeks of the year...
#
# We have a wrap-up here:
# https://www.timeanddate.com/news/time/south-australia-extends-dst.html
###############################################################################
# New Zealand
# From Mark Davies (1990-10-03):
# the 1989/90 year was a trial of an extended "daylight saving" period.
# This trial was deemed successful and the extended period adopted for
# subsequent years (with the addition of a further week at the start).
# source - phone call to Ministry of Internal Affairs Head Office.
# From George Shepherd via Simon Woodhead via Robert Elz (1991-03-06):
# # The Country of New Zealand (Australia's east island -) Gee they hate that!
# # or is Australia the west island of N.Z.
# # [ courtesy of Geoff Tribble.. Auckland N.Z. ]
# # [ Nov 1990 ]
# ...
# Rule NZ 1974 1988 - Oct lastSun 2:00 1:00 D
# Rule NZ 1989 max - Oct Sun>=1 2:00 1:00 D
# Rule NZ 1975 1989 - Mar Sun>=1 3:00 0 S
# Rule NZ 1990 max - Mar lastSun 3:00 0 S
# ...
# Zone NZ 12:00 NZ NZ%sT # New Zealand
# Zone NZ-CHAT 12:45 - NZ-CHAT # Chatham Island
# From Arthur David Olson (1992-03-08):
# The chosen rules use the Davies October 8 values for the start of DST in 1989
# rather than the October 1 value.
# From Paul Eggert (1995-12-19);
# Shank & Pottenger report 2:00 for all autumn changes in Australia and NZ.
# Robert Uzgalis writes that the New Zealand Daylight
# Savings Time Order in Council dated 1990-06-18 specifies 2:00 standard
# time on both the first Sunday in October and the third Sunday in March.
# As with Australia, we'll assume the tradition is 2:00s, not 2:00.
#
# From Paul Eggert (2006-03-22):
# The Department of Internal Affairs (DIA) maintains a brief history,
# as does Carol Squires; see tz-link.html for the full references.
# Use these sources in preference to Shanks & Pottenger.
#
# For Chatham, IATA SSIM (1991/1999) gives the NZ rules but with
# transitions at 2:45 local standard time; this confirms that Chatham
# is always exactly 45 minutes ahead of Auckland.
# From Colin Sharples (2007-04-30):
# DST will now start on the last Sunday in September, and end on the
# first Sunday in April. The changes take effect this year, meaning
# that DST will begin on 2007-09-30 2008-04-06.
# http://www.dia.govt.nz/diawebsite.nsf/wpg_URL/Services-Daylight-Saving-Daylight-saving-to-be-extended
# From Paul Eggert (2014-07-14):
# Chatham Island time was formally standardized on 1957-01-01 by
# New Zealand's Standard Time Amendment Act 1956 (1956-10-26).
# https://www.austlii.edu.au/nz/legis/hist_act/staa19561956n100244.pdf
# According to Google Books snippet view, a speaker in the New Zealand
# parliamentary debates in 1956 said "Clause 78 makes provision for standard
# time in the Chatham Islands. The time there is 45 minutes in advance of New
# Zealand time. I understand that is the time they keep locally, anyhow."
# For now, assume this practice goes back to the introduction of standard time
# in New Zealand, as this would make Chatham Islands time almost exactly match
# LMT back when New Zealand was at UT +11:30; also, assume Chatham Islands did
# not observe New Zealand's prewar DST.
###############################################################################
# Bonin (Ogasawara) Islands and Marcus Island (Minami-Tori-shima)
# From Wakaba (2019-01-28) via Phake Nick:
# National Diet Library of Japan has several reports by Japanese Government
# officers that describe the time used in islands when they visited there.
# According to them (and other sources such as newspapers), standard time UTC
# + 10 (JST + 1) and DST UTC + 11 (JST + 2) was used until its return to Japan
# at 1968-06-26 00:00 JST. The exact periods of DST are still unknown.
# I guessed Guam, Mariana, and Bonin and Marcus districts might have
# synchronized their DST periods, but reports imply they had their own
# decisions, i.e. there were three or more different time zones....
#
# https://wiki.suikawiki.org/n/小笠原諸島の標準時
# From Phake Nick (2019-02-12):
# Because their last time change to return to Japanese time when they returned
# to Japanese rule was right before 1970, ... per the current tz database
# rule, the information doesn't warrant creation of a new timezone for Bonin
# Islands itself and is thus as an anecdotal note for interest purpose only.
# ... [The abovementioned link] described some special timekeeping phenomenon
# regarding Marcus island, another remote island currently owned by Japanese
# in the same administrative unit as Bonin Islands. Many reports claim that
# the American coastal guard on the American quarter of the island use its own
# coastal guard time, and most sources describe the time as UTC+11, being two
# hours faster than JST used by some Japanese personnel on the island. Some
# sites describe it as same as Wake Island/Guam time although it would be
# incorrect to be same as Guam. And then in a few Japanese governmental
# report from 1980s (from National Institute of Information and Communications
# Technology) regarding the construction of VLBI facility on the Marcus
# Island, it claimed that there are three time standards being used on the
# island at the time which include not just JST (UTC+9) or [US]CG time
# (UTC+11) but also a JMSDF time (UTC+10) (Japan Maritime Self-Defense
# Force). Unfortunately there are no other sources that mentioned such time
# and there are also no information on things like how the time was used.
# Fiji
# Howse writes (p 153) that in 1879 the British governor of Fiji
# enacted an ordinance standardizing the islands on Antipodean Time
# instead of the American system (which was one day behind).
# From Rives McDow (1998-10-08):
# Fiji will introduce DST effective 0200 local time, 1998-11-01
# until 0300 local time 1999-02-28. Each year the DST period will
# be from the first Sunday in November until the last Sunday in February.
# From Paul Eggert (2000-01-08):
# IATA SSIM (1999-09) says DST ends 0100 local time. Go with McDow.
# From the BBC World Service in
# http://news.bbc.co.uk/2/hi/asia-pacific/205226.stm (1998-10-31 16:03 UTC):
# The Fijian government says the main reasons for the time change is to
# improve productivity and reduce road accidents.... [T]he move is also
# intended to boost Fiji's ability to attract tourists to witness the dawning
# of the new millennium.
# http://www.fiji.gov.fj/press/2000_09/2000_09_13-05.shtml (2000-09-13)
# reports that Fiji has discontinued DST.
# Kiribati
# From Paul Eggert (1996-01-22):
# Today's _Wall Street Journal_ (page 1) reports that Kiribati
# "declared it the same day [throughout] the country as of Jan. 1, 1995"
# as part of the competition to be first into the 21st century.
# From Kerry Shetline (2018-02-03):
# December 31 was the day that was skipped, so that the transition
# would be from Friday December 30, 1994 to Sunday January 1, 1995.
# From Paul Eggert (2018-02-04):
# One source for this is page 202 of: Bartky IR. One Time Fits All:
# The Campaigns for Global Uniformity (2007).
# Kwajalein
# From an AP article (1993-08-22):
# "The nearly 3,000 Americans living on this remote Pacific atoll have a good
# excuse for not remembering Saturday night: there wasn't one. Residents were
# going to bed Friday night and waking up Sunday morning because at midnight
# -- 8 A.M. Eastern daylight time on Saturday -- Kwajalein was jumping from
# one side of the international date line to the other."
# "In Marshall Islands, Friday is followed by Sunday", NY Times. 1993-08-22.
# https://www.nytimes.com/1993/08/22/world/in-marshall-islands-friday-is-followed-by-sunday.html
# From Phake Nick (2018-10-27):
# <https://wiki.suikawiki.org/n/南洋群島の標準時> ... pointed out that
# currently tzdata say Pacific/Kwajalein switched from GMT+11 to GMT-12 in
# 1969 October without explanation, however an 1993 article from NYT say it
# synchorized its day with US mainland about 40 years ago and thus the switch
# should occur at around 1950s instead.
#
# From Paul Eggert (2018-11-18):
# The NYT (actually, AP) article is vague and possibly wrong about this.
# The article says the earlier switch was "40 years ago when the United States
# Army established a missile test range here". However, the Kwajalein Test
# Center was established on 1960-10-01 and was run by the US Navy. It was
# transferred to the US Army on 1964-07-01. See "Seize the High Ground"
# <https://history.army.mil/html/books/070/70-88-1/cmhPub_70-88-1.pdf>.
# Given that Shanks was right on the money about the 1993 change, I'm inclined
# to take Shanks's word for the 1969 change unless we find better evidence.
# N Mariana Is, Guam
# From Phake Nick (2018-10-27):
# Guam Island was briefly annexed by Japan during ... year 1941-1944 ...
# however there are no detailed information about what time it use during that
# period. It would probably be reasonable to assume Guam use GMT+9 during
# that period of time like the surrounding area.
# From Paul Eggert (2018-11-18):
# Howse writes (p 153) "The Spaniards, on the other hand, reached the
# Philippines and the Ladrones from America," and implies that the Ladrones
# (now called the Marianas) kept American date for quite some time.
# For now, we assume the Ladrones switched at the same time as the Philippines;
# see Asia/Manila.
#
# Use 1941-12-10 and 1944-07-31 for Guam WWII transitions, as the rough start
# and end of Japanese control of Agana. We don't know whether the Northern
# Marianas followed Guam's DST rules from 1959 through 1977; for now, assume
# they did as that avoids the need for a separate zone due to our 1970 cutoff.
#
# US Public Law 106-564 (2000-12-23) made UT +10 the official standard time,
# under the name "Chamorro Standard Time". There is no official abbreviation,
# but Congressman Robert A. Underwood, author of the bill that became law,
# wrote in a press release (2000-12-27) that he will seek the use of "ChST".
# See also the commentary for Micronesia.
# Marshall Is
# See the commentary for Micronesia.
# Micronesia (and nearby)
# From Paul Eggert (2018-11-18):
# Like the Ladrones (see Guam commentary), assume the Spanish East Indies
# kept American time until the Philippines switched at the end of 1844.
# Alan Eugene Davis writes (1996-03-16),
# "I am certain, having lived there for the past decade, that 'Truk'
# (now properly known as Chuuk) ... is in the time zone GMT+10."
#
# Shanks & Pottenger write that Truk switched from UT +10 to +11
# on 1978-10-01; ignore this for now.
# From Paul Eggert (1999-10-29):
# The Federated States of Micronesia Visitors Board writes in
# The Federated States of Micronesia - Visitor Information (1999-01-26)
# http://www.fsmgov.org/info/clocks.html
# that Truk and Yap are UT +10, and Ponape and Kosrae are +11.
# We don't know when Kosrae switched from +12; assume January 1 for now.
# From Phake Nick (2018-10-27):
#
# From a Japanese wiki site https://wiki.suikawiki.org/n/南洋群島の標準時
# ...
# For "Southern Islands" (modern region of Mariana + Palau + Federation of
# Micronesia + Marshall Islands):
#
# A 1906 Japanese magazine shown the Caroline Islands and Mariana Islands
# who was occupied by Germany at the time as GMT+10, together with the like
# of German New Guinea. However there is a marking saying it have not been
# implemented (yet). No further information after that were found.
#
# Japan invaded those islands in 1914, and records shows that they were
# instructed to use JST at the time.
#
# 1915 January telecommunication record on the Jaluit Atoll shows they use
# the meridian of 170E as standard time (GMT+11:20), which is similar to the
# longitude of the atoll.
# 1915 February record say the 170E standard time is to be used until
# February 9 noon, and after February 9 noon they are to use JST.
# However these are time used within the Japanese Military at the time and
# probably does not reflect the time used by local resident at the time (that
# is if they keep their own time back then)
#
# In January 1919 the occupying force issued a command that split the area
# into three different timezone with meridian of 135E, 150E, 165E (JST+0, +1,
# +2), and the command was to become effective from February 1 of the same
# year. Despite the target of the command is still only for the occupying
# force itself, further publication have described the time as the standard
# time for the occupied area and thus it can probably be seen as such.
# * Area that use meridian of 135E: Palau and Yap civil administration area
# (Southern Islands Western Standard Time)
# * Area that use meridian of 150E: Truk (Chuuk) and Saipan civil
# administration area (Southern Islands Central Standard Time)
# * Area that use meridian of 165E: Ponape (Pohnpei) and Jaluit civil
# administration area (Southern Islands Eastern Standard Time).
# * In the next few years Japanese occupation of those islands have been
# formalized via League of Nation Mandate (South Pacific Mandate) and formal
# governance structure have been established, these district [become
# subprefectures] and timezone classification have been inherited as standard
# time of the area.
# * Saipan subprefecture include Mariana islands (exclude Guam which was
# occupied by America at the time), Palau and Yap subprefecture rule the
# Western Caroline Islands with 137E longitude as border, Truk and Ponape
# subprefecture rule the Eastern Caroline Islands with 154E as border, Ponape
# subprefecture also rule part of Marshall Islands to the west of 164E
# starting from (1918?) and Jaluit subprefecture rule the rest of the
# Marshall Islands.
#
# And then in year 1937, an announcement was made to change the time in the
# area into 2 timezones:
# * Area that use meridian of 135E: area administered by Palau, Yap and
# Saipan subprefecture (Southern Islands Western Standard Time)
# * Area that use meridian of 150E: area administered by Truk (Chuuk),
# Ponape (Pohnpei) and Jaluit subprefecture (Southern Islands Eastern
# Standard Time)
#
# Another announcement issued in 1941 say that on April 1 that year,
# standard time of the Southern Islands would be changed to use the meridian
# of 135E (GMT+9), and thus abolishing timezone different within the area.
#
# Then Pacific theater of WWII started and Japan slowly lose control on the
# island. The webpage I linked above contain no information during this
# period of time....
#
# After the end of WWII, in 1946 February, a document written by the
# (former?) Japanese military personnel describe there are 3 hours time
# different between Caroline islands time/Wake island time and the Chungking
# time, which would mean the time being used there at the time was GMT+10.
#
# After that, the area become Trust Territories of the Pacific Islands
# under American administration from year 1947. The site listed some
# American/International books/maps/publications about time used in those
# area during this period of time but they doesn't seems to be reliable
# information so it would be the best if someone know where can more reliable
# information can be found.
#
#
# From Paul Eggert (2018-11-18):
#
# For the above, use vague dates like "1914" and "1945" for transitions that
# plausibly exist but for which the details are not known. The information
# for Wake is too sketchy to act on.
#
# The 1906 GMT+10 info about German-controlled islands might not have been
# done, so omit it from the data for now.
#
# The Jaluit info governs Kwajalein.
# Midway
# From Charles T O'Connor, KMTH DJ (1956),
# quoted in the KTMH section of the Radio Heritage Collection
# <http://radiodx.com/spdxr/KMTH.htm> (2002-12-31):
# For the past two months we've been on what is known as Daylight
# Saving Time. This time has put us on air at 5am in the morning,
# your time down there in New Zealand. Starting September 2, 1956
# we'll again go back to Standard Time. This'll mean that we'll go to
# air at 6am your time.
#
# From Paul Eggert (2003-03-23):
# We don't know the date of that quote, but we'll guess they
# started DST on June 3. Possibly DST was observed other years
# in Midway, but we have no record of it.
# Nauru
# From Phake Nick (2018-10-31):
# Currently, the tz database say Nauru use LMT until 1921, and then
# switched to GMT+11:30 for the next two decades.
# However, a number of timezone map published in America/Japan back then
# showed its timezone as GMT+11 per https://wiki.suikawiki.org/n/ナウルの標準時
# And it would also be nice if the 1921 transition date could be sourced.
# ...
# The "Nauru Standard Time Act 1978 Time Change"
# http://ronlaw.gov.nr/nauru_lpms/files/gazettes/4b23a17d2030150404db7a5fa5872f52.pdf#page=3
# based on "Nauru Standard Time Act 1978 Time Change"
# http://www.paclii.org/nr/legis/num_act/nsta1978207/ defined that "Nauru
# Alternative Time" (GMT+12) should be in effect from 1979 Feb.
#
# From Paul Eggert (2018-11-19):
# The 1921-01-15 introduction of standard time is in Shanks; it is also in
# "Standard Time Throughout the World", US National Bureau of Standards (1935),
# page 3, which does not give the UT offset. In response to a comment by
# Phake Nick I set the Nauru time of occupation by Japan to
# 1942-08-29/1945-09-08 by using dates from:
# https://en.wikipedia.org/wiki/Japanese_occupation_of_Nauru
# Norfolk
# From Alexander Krivenyshev (2015-09-23):
# Norfolk Island will change ... from +1130 to +1100:
# https://www.comlaw.gov.au/Details/F2015L01483/Explanatory%20Statement/Text
# ... at 12.30 am (by legal time in New South Wales) on 4 October 2015.
# http://www.norfolkisland.gov.nf/nia/MediaRelease/Media%20Release%20Norfolk%20Island%20Standard%20Time%20Change.pdf
-# From Paul Eggert (2015-09-23):
+# From Paul Eggert (2019-08-28):
# Transitions before 2015 are from timeanddate.com, which consulted
# the Norfolk Island Museum and the Australian Bureau of Meteorology's
# Norfolk Island station, and found no record of Norfolk observing DST
# other than in 1974/5. See:
# https://www.timeanddate.com/time/australia/norfolk-island.html
+# However, disagree with timeanddate about the 1975-03-02 transition;
+# timeanddate has 02:00 but 02:00s corresponds to what the NSW law said
+# (thanks to Michael Deckers).
+
+# Norfolk started observing Australian DST in spring 2019.
+# From Kyle Czech (2019-08-13):
+# https://www.legislation.gov.au/Details/F2018L01702
+# From Michael Deckers (2019-08-14):
+# https://www.legislation.gov.au/Details/F2019C00010
# Palau
# See commentary for Micronesia.
# Pitcairn
# From Rives McDow (1999-11-08):
# A Proclamation was signed by the Governor of Pitcairn on the 27th March 1998
# with regard to Pitcairn Standard Time. The Proclamation is as follows.
#
# The local time for general purposes in the Islands shall be
# Co-ordinated Universal time minus 8 hours and shall be known
# as Pitcairn Standard Time.
#
# ... I have also seen Pitcairn listed as UTC minus 9 hours in several
# references, and can only assume that this was an error in interpretation
# somehow in light of this proclamation.
# From Rives McDow (1999-11-09):
# The Proclamation regarding Pitcairn time came into effect on 27 April 1998
# ... at midnight.
# From Howie Phelps (1999-11-10), who talked to a Pitcairner via shortwave:
# Betty Christian told me yesterday that their local time is the same as
# Pacific Standard Time. They used to be ½ hour different from us here in
# Sacramento but it was changed a couple of years ago.
# (Western) Samoa and American Samoa
# Howse writes (p 153) that after the 1879 standardization on Antipodean
# time by the British governor of Fiji, the King of Samoa decided to change
# "the date in his kingdom from the Antipodean to the American system,
# ordaining - by a masterpiece of diplomatic flattery - that
# the Fourth of July should be celebrated twice in that year."
# This happened in 1892, according to the Evening News (Sydney) of 1892-07-20.
# https://www.staff.science.uu.nl/~gent0113/idl/idl.htm
# Although Shanks & Pottenger says they both switched to UT -11:30
# in 1911, and to -11 in 1950. many earlier sources give -11
# for American Samoa, e.g., the US National Bureau of Standards
# circular "Standard Time Throughout the World", 1932.
# Assume American Samoa switched to -11 in 1911, not 1950,
# and that after 1950 they agreed until (western) Samoa skipped a
# day in 2011. Assume also that the Samoas follow the US and New
# Zealand's "ST"/"DT" style of daylight-saving abbreviations.
# Tonga
# From Paul Eggert (1996-01-22):
# Today's _Wall Street Journal_ (p 1) reports that "Tonga has been plotting
# to sneak ahead of [New Zealanders] by introducing daylight-saving time."
# Since Kiribati has moved the Date Line it's not clear what Tonga will do.
# Don Mundell writes in the 1997-02-20 Tonga Chronicle
# How Tonga became 'The Land where Time Begins':
# http://www.tongatapu.net.to/tonga/homeland/timebegins.htm
#
# Until 1941 Tonga maintained a standard time 50 minutes ahead of NZST
# 12 hours and 20 minutes ahead of GMT. When New Zealand adjusted its
# standard time in 1940s, Tonga had the choice of subtracting from its
# local time to come on the same standard time as New Zealand or of
# advancing its time to maintain the differential of 13°
# (approximately 50 minutes ahead of New Zealand time).
#
# Because His Majesty King Tāufaʻāhau Tupou IV, then Crown Prince
# Tungī, preferred to ensure Tonga's title as the land where time
# begins, the Legislative Assembly approved the latter change.
#
# But some of the older, more conservative members from the outer
# islands objected. "If at midnight on Dec. 31, we move ahead 40
# minutes, as your Royal Highness wishes, what becomes of the 40
# minutes we have lost?"
#
# The Crown Prince, presented an unanswerable argument: "Remember that
# on the World Day of Prayer, you would be the first people on Earth
# to say your prayers in the morning."
# From Paul Eggert (2006-03-22):
# Shanks & Pottenger say the transition was on 1968-10-01; go with Mundell.
# From Eric Ulevik (1999-05-03):
# Tonga's director of tourism, who is also secretary of the National Millennium
# Committee, has a plan to get Tonga back in front.
# He has proposed a one-off move to tropical daylight saving for Tonga from
# October to March, which has won approval in principle from the Tongan
# Government.
# From Steffen Thorsen (1999-09-09):
# * Tonga will introduce DST in November
#
# I was given this link by John Letts:
# http://news.bbc.co.uk/hi/english/world/asia-pacific/newsid_424000/424764.stm
#
# I have not been able to find exact dates for the transition in November
# yet. By reading this article it seems like Fiji will be 14 hours ahead
# of UTC as well, but as far as I know Fiji will only be 13 hours ahead
# (12 + 1 hour DST).
# From Arthur David Olson (1999-09-20):
# According to <http://www.tongaonline.com/news/sept1799.html>:
# "Daylight Savings Time will take effect on Oct. 2 through April 15, 2000
# and annually thereafter from the first Saturday in October through the
# third Saturday of April. Under the system approved by Privy Council on
# Sept. 10, clocks must be turned ahead one hour on the opening day and
# set back an hour on the closing date."
# Alas, no indication of the time of day.
# From Rives McDow (1999-10-06):
# Tonga started its Daylight Saving on Saturday morning October 2nd at 0200am.
# Daylight Saving ends on April 16 at 0300am which is Sunday morning.
# From Steffen Thorsen (2000-10-31):
# Back in March I found a notice on the website http://www.tongaonline.com
# that Tonga changed back to standard time one month early, on March 19
# instead of the original reported date April 16. Unfortunately, the article
# is no longer available on the site, and I did not make a copy of the
# text, and I have forgotten to report it here.
# (Original URL was <http://www.tongaonline.com/news/march162000.htm>)
# From Rives McDow (2000-12-01):
# Tonga is observing DST as of 2000-11-04 and will stop on 2001-01-27.
# From Sione Moala-Mafi (2001-09-20) via Rives McDow:
# At 2:00am on the first Sunday of November, the standard time in the Kingdom
# shall be moved forward by one hour to 3:00am. At 2:00am on the last Sunday
# of January the standard time in the Kingdom shall be moved backward by one
# hour to 1:00am.
# From Pulu ʻAnau (2002-11-05):
# The law was for 3 years, supposedly to get renewed. It wasn't.
# From Pulu ʻAnau (2016-10-27):
# http://mic.gov.to/news-today/press-releases/6375-daylight-saving-set-to-run-from-6-november-2016-to-15-january-2017
# Cannot find anyone who knows the rules, has seen the duration or has seen
# the cabinet decision, but it appears we are following Fiji's rule set.
#
# From Tim Parenti (2016-10-26):
# Assume Tonga will observe DST from the first Sunday in November at 02:00
# through the third Sunday in January at 03:00, like Fiji, for now.
# From David Wade (2017-10-18):
# In August government was disolved by the King. The current prime minister
# continued in office in care taker mode. It is easy to see that few
# decisions will be made until elections 16th November.
#
# From Paul Eggert (2017-10-18):
# For now, guess that DST is discontinued. That's what the IATA is guessing.
# Wake
# From Vernice Anderson, Personal Secretary to Philip Jessup,
# US Ambassador At Large (oral history interview, 1971-02-02):
#
# Saturday, the 14th [of October, 1950] - ... The time was all the
# more confusing at that point, because we had crossed the
# International Date Line, thus getting two Sundays. Furthermore, we
# discovered that Wake Island had two hours of daylight saving time
# making calculation of time in Washington difficult if not almost
# impossible.
#
# https://www.trumanlibrary.org/oralhist/andrsonv.htm
# From Paul Eggert (2003-03-23):
# We have no other report of DST in Wake Island, so omit this info for now.
# See also the commentary for Micronesia.
###############################################################################
# The International Date Line
# From Gwillim Law (2000-01-03):
#
# The International Date Line is not defined by any international standard,
# convention, or treaty. Mapmakers are free to draw it as they please.
# Reputable mapmakers will simply ensure that every point of land appears on
# the correct side of the IDL, according to the date legally observed there.
#
# When Kiribati adopted a uniform date in 1995, thereby moving the Phoenix and
# Line Islands to the west side of the IDL (or, if you prefer, moving the IDL
# to the east side of the Phoenix and Line Islands), I suppose that most
# mapmakers redrew the IDL following the boundary of Kiribati. Even that line
# has a rather arbitrary nature. The straight-line boundaries between Pacific
# island nations that are shown on many maps are based on an international
# convention, but are not legally binding national borders.... The date is
# governed by the IDL; therefore, even on the high seas, there may be some
# places as late as fourteen hours later than UTC. And, since the IDL is not
# an international standard, there are some places on the high seas where the
# correct date is ambiguous.
# From Wikipedia <https://en.wikipedia.org/wiki/Time_zone> (2005-08-31):
# Before 1920, all ships kept local apparent time on the high seas by setting
# their clocks at night or at the morning sight so that, given the ship's
# speed and direction, it would be 12 o'clock when the Sun crossed the ship's
# meridian (12 o'clock = local apparent noon). During 1917, at the
# Anglo-French Conference on Time-keeping at Sea, it was recommended that all
# ships, both military and civilian, should adopt hourly standard time zones
# on the high seas. Whenever a ship was within the territorial waters of any
# nation it would use that nation's standard time. The captain was permitted
# to change his ship's clocks at a time of his choice following his ship's
# entry into another zone time - he often chose midnight. These zones were
# adopted by all major fleets between 1920 and 1925 but not by many
# independent merchant ships until World War II.
# From Paul Eggert, using references suggested by Oscar van Vlijmen
# (2005-03-20):
#
# The American Practical Navigator (2002)
# http://pollux.nss.nima.mil/pubs/pubs_j_apn_sections.html?rid=187
# talks only about the 180-degree meridian with respect to ships in
# international waters; it ignores the international date line.
Index: stable/12/contrib/tzdata/backzone
===================================================================
--- stable/12/contrib/tzdata/backzone (revision 352352)
+++ stable/12/contrib/tzdata/backzone (revision 352353)
@@ -1,699 +1,715 @@
# Zones that go back beyond the scope of the tz database
# This file is in the public domain.
# This file is by no means authoritative; if you think you know
# better, go ahead and edit it (and please send any changes to
# tz@iana.org for general use in the future). For more, please see
# the file CONTRIBUTING in the tz distribution.
# From Paul Eggert (2014-10-31):
# This file contains data outside the normal scope of the tz database,
# in that its zones do not differ from normal tz zones after 1970.
# Links in this file point to zones in this file, superseding links in
# the file 'backward'.
# Although zones in this file may be of some use for analyzing
# pre-1970 timestamps, they are less reliable, cover only a tiny
# sliver of the pre-1970 era, and cannot feasibly be improved to cover
# most of the era. Because the zones are out of normal scope for the
# database, less effort is put into maintaining this file. Many of
# the zones were formerly in other source files, but were removed or
# replaced by links as their data entries were questionable and/or they
# differed from other zones only in pre-1970 timestamps.
# Unless otherwise specified, the source for data through 1990 is:
# Thomas G. Shanks and Rique Pottenger, The International Atlas (6th edition),
# San Diego: ACS Publications, Inc. (2003).
# Unfortunately this book contains many errors and cites no sources.
# This file is not intended to be compiled standalone, as it
# assumes rules from other files. In the tz distribution, use
# 'make PACKRATDATA=backzone zones' to compile and install this file.
# Zones are sorted by zone name. Each zone is preceded by the
# name of the country that the zone is in, along with any other
# commentary and rules associated with the entry.
#
# As explained in the zic man page, the zone columns are:
# Zone NAME STDOFF RULES FORMAT [UNTIL]
# Ethiopia
# From Paul Eggert (2014-07-31):
# Like the Swahili of Kenya and Tanzania, many Ethiopians keep a
# 12-hour clock starting at our 06:00, so their "8 o'clock" is our
# 02:00 or 14:00. Keep this in mind when you ask the time in Amharic.
#
# Shanks & Pottenger write that Ethiopia had six narrowly-spaced time
# zones between 1870 and 1890, that they merged to 38E50 (2:35:20) in
# 1890, and that they switched to 3:00 on 1936-05-05. Perhaps 38E50
# was for Adis Dera. Quite likely the Shanks data entries are wrong
# anyway.
Zone Africa/Addis_Ababa 2:34:48 - LMT 1870
2:35:20 - ADMT 1936 May 5 # Adis Dera MT
3:00 - EAT
# Eritrea
Zone Africa/Asmara 2:35:32 - LMT 1870
2:35:32 - AMT 1890 # Asmara Mean Time
2:35:20 - ADMT 1936 May 5 # Adis Dera MT
3:00 - EAT
Link Africa/Asmara Africa/Asmera
# Mali (southern)
Zone Africa/Bamako -0:32:00 - LMT 1912
0:00 - GMT 1934 Feb 26
-1:00 - -01 1960 Jun 20
0:00 - GMT
# Central African Republic
Zone Africa/Bangui 1:14:20 - LMT 1912
1:00 - WAT
# Gambia
Zone Africa/Banjul -1:06:36 - LMT 1912
-1:06:36 - BMT 1935 # Banjul Mean Time
-1:00 - -01 1964
0:00 - GMT
# Malawi
Zone Africa/Blantyre 2:20:00 - LMT 1903 Mar
2:00 - CAT
# Republic of the Congo
Zone Africa/Brazzaville 1:01:08 - LMT 1912
1:00 - WAT
# Burundi
Zone Africa/Bujumbura 1:57:28 - LMT 1890
2:00 - CAT
# Guinea
Zone Africa/Conakry -0:54:52 - LMT 1912
0:00 - GMT 1934 Feb 26
-1:00 - -01 1960
0:00 - GMT
# Senegal
Zone Africa/Dakar -1:09:44 - LMT 1912
-1:00 - -01 1941 Jun
0:00 - GMT
# Tanzania
Zone Africa/Dar_es_Salaam 2:37:08 - LMT 1931
3:00 - EAT 1948
2:45 - +0245 1961
3:00 - EAT
# Djibouti
Zone Africa/Djibouti 2:52:36 - LMT 1911 Jul
3:00 - EAT
# Cameroon
# Whitman says they switched to 1:00 in 1920; go with Shanks & Pottenger.
Zone Africa/Douala 0:38:48 - LMT 1912
1:00 - WAT
# Sierra Leone
# From Paul Eggert (2014-08-12):
# The following table is from Shanks & Pottenger, but it can't be right.
# Whitman gives Mar 31 - Aug 31 for 1931 on.
# The International Hydrographic Bulletin, 1932-33, p 63 says that
# Sierra Leone would advance its clocks by 20 minutes on 1933-10-01.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule SL 1935 1942 - Jun 1 0:00 0:40 -0020
Rule SL 1935 1942 - Oct 1 0:00 0 -01
Rule SL 1957 1962 - Jun 1 0:00 1:00 +01
Rule SL 1957 1962 - Sep 1 0:00 0 GMT
Zone Africa/Freetown -0:53:00 - LMT 1882
-0:53:00 - FMT 1913 Jun # Freetown Mean Time
-1:00 SL %s 1957
0:00 SL GMT/+01
# Botswana
# From Paul Eggert (2013-02-21):
# Milne says they were regulated by the Cape Town Signal in 1899;
# assume they switched to 2:00 when Cape Town did.
Zone Africa/Gaborone 1:43:40 - LMT 1885
1:30 - SAST 1903 Mar
2:00 - CAT 1943 Sep 19 2:00
2:00 1:00 CAST 1944 Mar 19 2:00
2:00 - CAT
# Zimbabwe
Zone Africa/Harare 2:04:12 - LMT 1903 Mar
2:00 - CAT
# Uganda
Zone Africa/Kampala 2:09:40 - LMT 1928 Jul
3:00 - EAT 1930
2:30 - +0230 1948
2:45 - +0245 1957
3:00 - EAT
# Rwanda
Zone Africa/Kigali 2:00:16 - LMT 1935 Jun
2:00 - CAT
# Democratic Republic of the Congo (west)
Zone Africa/Kinshasa 1:01:12 - LMT 1897 Nov 9
1:00 - WAT
# Gabon
Zone Africa/Libreville 0:37:48 - LMT 1912
1:00 - WAT
# Togo
Zone Africa/Lome 0:04:52 - LMT 1893
0:00 - GMT
# Angola
#
# From Paul Eggert (2018-02-16):
# Shanks gives 1911-05-26 for the transition to WAT,
# evidently confusing the date of the Portuguese decree
# (see Europe/Lisbon) with the date that it took effect.
#
Zone Africa/Luanda 0:52:56 - LMT 1892
0:52:04 - LMT 1911 Dec 31 23:00u # Luanda MT?
1:00 - WAT
# Democratic Republic of the Congo (east)
Zone Africa/Lubumbashi 1:49:52 - LMT 1897 Nov 9
2:00 - CAT
# Zambia
Zone Africa/Lusaka 1:53:08 - LMT 1903 Mar
2:00 - CAT
# Equatorial Guinea
#
# Although Shanks says that Malabo switched from UT +00 to +01 on 1963-12-15,
# a Google Books search says that London Calling, Issues 432-465 (1948), p 19,
# says that Spanish Guinea was at +01 back then. The Shanks data entries
# are most likely wrong, but we have nothing better; use them here for now.
#
Zone Africa/Malabo 0:35:08 - LMT 1912
0:00 - GMT 1963 Dec 15
1:00 - WAT
# Lesotho
Zone Africa/Maseru 1:50:00 - LMT 1903 Mar
2:00 - SAST 1943 Sep 19 2:00
2:00 1:00 SAST 1944 Mar 19 2:00
2:00 - SAST
# Eswatini (formerly Swaziland)
Zone Africa/Mbabane 2:04:24 - LMT 1903 Mar
2:00 - SAST
# Somalia
Zone Africa/Mogadishu 3:01:28 - LMT 1893 Nov
3:00 - EAT 1931
2:30 - +0230 1957
3:00 - EAT
# Niger
Zone Africa/Niamey 0:08:28 - LMT 1912
-1:00 - -01 1934 Feb 26
0:00 - GMT 1960
1:00 - WAT
# Mauritania
Zone Africa/Nouakchott -1:03:48 - LMT 1912
0:00 - GMT 1934 Feb 26
-1:00 - -01 1960 Nov 28
0:00 - GMT
# Burkina Faso
Zone Africa/Ouagadougou -0:06:04 - LMT 1912
0:00 - GMT
# Benin
# Whitman says they switched to 1:00 in 1946, not 1934;
# go with Shanks & Pottenger.
Zone Africa/Porto-Novo 0:10:28 - LMT 1912 Jan 1
0:00 - GMT 1934 Feb 26
1:00 - WAT
# Mali (northern)
Zone Africa/Timbuktu -0:12:04 - LMT 1912
0:00 - GMT
# Anguilla
Zone America/Anguilla -4:12:16 - LMT 1912 Mar 2
-4:00 - AST
# Antigua and Barbuda
Zone America/Antigua -4:07:12 - LMT 1912 Mar 2
-5:00 - EST 1951
-4:00 - AST
# Chubut, Argentina
# The name "Comodoro Rivadavia" exceeds the 14-byte POSIX limit.
Zone America/Argentina/ComodRivadavia -4:30:00 - LMT 1894 Oct 31
-4:16:48 - CMT 1920 May
-4:00 - -04 1930 Dec
-4:00 Arg -04/-03 1969 Oct 5
-3:00 Arg -03/-02 1991 Mar 3
-4:00 - -04 1991 Oct 20
-3:00 Arg -03/-02 1999 Oct 3
-4:00 Arg -04/-03 2000 Mar 3
-3:00 - -03 2004 Jun 1
-4:00 - -04 2004 Jun 20
-3:00 - -03
# Aruba
Zone America/Aruba -4:40:24 - LMT 1912 Feb 12 # Oranjestad
-4:30 - -0430 1965
-4:00 - AST
# Cayman Is
Zone America/Cayman -5:25:32 - LMT 1890 # Georgetown
-5:07:10 - KMT 1912 Feb # Kingston Mean Time
-5:00 - EST
# United States
#
# From Paul Eggert (2018-03-18):
# America/Chillicothe would be tricky, as it was a city of two-timers:
# "To prevent a constant mixup at Chillicothe, caused by the courthouse
# clock running on central time and the city running on 'daylight saving'
# time, a third hand was added to the dial of the courthouse clock."
# -- Ohio news in brief. The Cedarville Herald. 1920-05-21;43(21):1 (col. 5)
# https://digitalcommons.cedarville.edu/cedarville_herald/794
# Canada
Zone America/Coral_Harbour -5:32:40 - LMT 1884
-5:00 NT_YK E%sT 1946
-5:00 - EST
# Dominica
Zone America/Dominica -4:05:36 - LMT 1911 Jul 1 0:01 # Roseau
-4:00 - AST
# Baja California
# See 'northamerica' for why this entry is here rather than there.
Zone America/Ensenada -7:46:28 - LMT 1922 Jan 1 0:13:32
-8:00 - PST 1927 Jun 10 23:00
-7:00 - MST 1930 Nov 16
-8:00 - PST 1942 Apr
-7:00 - MST 1949 Jan 14
-8:00 - PST 1996
-8:00 Mexico P%sT
# Grenada
Zone America/Grenada -4:07:00 - LMT 1911 Jul # St George's
-4:00 - AST
# Guadeloupe
Zone America/Guadeloupe -4:06:08 - LMT 1911 Jun 8 # Pointe-à-Pitre
-4:00 - AST
# Canada
#
# From Paul Eggert (2015-03-24):
# Since 1970 most of Quebec has been like Toronto; see
# America/Toronto. However, earlier versions of the tz database
# mistakenly relied on data from Shanks & Pottenger saying that Quebec
# differed from Ontario after 1970, and the following rules and zone
# were created for most of Quebec from the incorrect Shanks &
# Pottenger data. The post-1970 entries have been corrected, but the
# pre-1970 entries are unchecked and probably have errors.
#
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Mont 1917 only - Mar 25 2:00 1:00 D
Rule Mont 1917 only - Apr 24 0:00 0 S
Rule Mont 1919 only - Mar 31 2:30 1:00 D
Rule Mont 1919 only - Oct 25 2:30 0 S
Rule Mont 1920 only - May 2 2:30 1:00 D
Rule Mont 1920 1922 - Oct Sun>=1 2:30 0 S
Rule Mont 1921 only - May 1 2:00 1:00 D
Rule Mont 1922 only - Apr 30 2:00 1:00 D
Rule Mont 1924 only - May 17 2:00 1:00 D
Rule Mont 1924 1926 - Sep lastSun 2:30 0 S
Rule Mont 1925 1926 - May Sun>=1 2:00 1:00 D
Rule Mont 1927 1937 - Apr lastSat 24:00 1:00 D
Rule Mont 1927 1937 - Sep lastSat 24:00 0 S
Rule Mont 1938 1940 - Apr lastSun 0:00 1:00 D
Rule Mont 1938 1939 - Sep lastSun 0:00 0 S
Rule Mont 1946 1973 - Apr lastSun 2:00 1:00 D
Rule Mont 1945 1948 - Sep lastSun 2:00 0 S
Rule Mont 1949 1950 - Oct lastSun 2:00 0 S
Rule Mont 1951 1956 - Sep lastSun 2:00 0 S
Rule Mont 1957 1973 - Oct lastSun 2:00 0 S
Zone America/Montreal -4:54:16 - LMT 1884
-5:00 Mont E%sT 1918
-5:00 Canada E%sT 1919
-5:00 Mont E%sT 1942 Feb 9 2:00s
-5:00 Canada E%sT 1946
-5:00 Mont E%sT 1974
-5:00 Canada E%sT
# Montserrat
# From Paul Eggert (2006-03-22):
# In 1995 volcanic eruptions forced evacuation of Plymouth, the capital.
# world.gazetteer.com says Cork Hill is the most populous location now.
Zone America/Montserrat -4:08:52 - LMT 1911 Jul 1 0:01 # Cork Hill
-4:00 - AST
# United States
#
# From Paul Eggert (2018-03-18):
# America/Palm_Springs would be tricky, as it kept two sets of clocks
# in 1946/7. See the following notes.
#
# From Steve Allen (2018-01-19):
# The shadow of Mt. San Jacinto brings darkness very early in the winter
# months. In 1946 the chamber of commerce decided to put the clocks of Palm
# Springs forward by an hour in the winter.
# https://www.desertsun.com/story/life/2017/12/27/palm-springs-struggle-daylight-savings-time-and-idea-sun-time/984416001/
# Desert Sun, Number 18, 1 November 1946
# https://cdnc.ucr.edu/cgi-bin/cdnc?a=d&d=DS19461101
# has proposal for meeting on front page and page 21.
# Desert Sun, Number 19, 5 November 1946
# https://cdnc.ucr.edu/cgi-bin/cdnc?a=d&d=DS19461105
# reports that Sun Time won at the meeting on front page and page 5.
# Desert Sun, Number 37, 7 January 1947
# https://cdnc.ucr.edu/cgi-bin/cdnc?a=d&d=DS19470107.2.12
# front page reports request to abandon Sun Time and page 7 notes a "class war".
# Desert Sun, Number 38, 10 January 1947
# https://cdnc.ucr.edu/cgi-bin/cdnc?a=d&d=DS19470110
# front page reports on end.
# Argentina
# This entry was intended for the following areas, but has been superseded by
# more detailed zones.
# Santa Fe (SF), Entre Ríos (ER), Corrientes (CN), Misiones (MN), Chaco (CC),
# Formosa (FM), La Pampa (LP), Chubut (CH)
Zone America/Rosario -4:02:40 - LMT 1894 Nov
-4:16:44 - CMT 1920 May
-4:00 - -04 1930 Dec
-4:00 Arg -04/-03 1969 Oct 5
-3:00 Arg -03/-02 1991 Jul
-3:00 - -03 1999 Oct 3 0:00
-4:00 Arg -04/-03 2000 Mar 3 0:00
-3:00 - -03
# St Kitts-Nevis
Zone America/St_Kitts -4:10:52 - LMT 1912 Mar 2 # Basseterre
-4:00 - AST
# St Lucia
Zone America/St_Lucia -4:04:00 - LMT 1890 # Castries
-4:04:00 - CMT 1912 # Castries Mean Time
-4:00 - AST
# Virgin Is
Zone America/St_Thomas -4:19:44 - LMT 1911 Jul # Charlotte Amalie
-4:00 - AST
# St Vincent and the Grenadines
Zone America/St_Vincent -4:04:56 - LMT 1890 # Kingstown
-4:04:56 - KMT 1912 # Kingstown Mean Time
-4:00 - AST
# British Virgin Is
Zone America/Tortola -4:18:28 - LMT 1911 Jul # Road Town
-4:00 - AST
# McMurdo, Ross Island, since 1955-12
Zone Antarctica/McMurdo 0 - -00 1956
12:00 NZ NZ%sT
Link Antarctica/McMurdo Antarctica/South_Pole
# Yemen
# Milne says 2:59:54 was the meridian of the saluting battery at Aden,
# and that Yemen was at 1:55:56, the meridian of the Hagia Sophia.
Zone Asia/Aden 2:59:54 - LMT 1950
3:00 - +03
# Bahrain
Zone Asia/Bahrain 3:22:20 - LMT 1920 # Manamah
4:00 - +04 1972 Jun
3:00 - +03
# India
#
# From Paul Eggert (2014-09-06):
# The 1876 Report of the Secretary of the [US] Navy, p 305 says that Madras
# civil time was 5:20:57.3.
#
# From Paul Eggert (2014-08-21):
# In tomorrow's The Hindu, Nitya Menon reports that India had two civil time
# zones starting in 1884, one in Bombay and one in Calcutta, and that railways
# used a third time zone based on Madras time (80° 18' 30" E). Also,
# in 1881 Bombay briefly switched to Madras time, but switched back. See:
# http://www.thehindu.com/news/cities/chennai/madras-375-when-madras-clocked-the-time/article6339393.ece
#Zone Asia/Chennai [not enough info to complete]
# China
# Long-shu Time (probably due to Long and Shu being two names of that area)
# Guangxi, Guizhou, Hainan, Ningxia, Sichuan, Shaanxi, and Yunnan;
# most of Gansu; west Inner Mongolia; west Qinghai; and the Guangdong
# counties Deqing, Enping, Kaiping, Luoding, Taishan, Xinxing,
# Yangchun, Yangjiang, Yu'nan, and Yunfu.
Zone Asia/Chongqing 7:06:20 - LMT 1928 # or Chungking
7:00 - +07 1980 May
8:00 PRC C%sT
Link Asia/Chongqing Asia/Chungking
# Vietnam
# From Paul Eggert (2014-10-13):
# See Asia/Ho_Chi_Minh for the source for this data.
# Trần's book says the 1954-55 transition to 07:00 in Hanoi was in
# October 1954, with exact date and time unspecified.
Zone Asia/Hanoi 7:03:24 - LMT 1906 Jul 1
7:06:30 - PLMT 1911 May 1
7:00 - +07 1942 Dec 31 23:00
8:00 - +08 1945 Mar 14 23:00
9:00 - +09 1945 Sep 2
7:00 - +07 1947 Apr 1
8:00 - +08 1954 Oct
7:00 - +07
# China
# Changbai Time ("Long-white Time", Long-white = Heilongjiang area)
# Heilongjiang (except Mohe county), Jilin
Zone Asia/Harbin 8:26:44 - LMT 1928 # or Haerbin
8:30 - +0830 1932 Mar
8:00 - CST 1940
9:00 - +09 1966 May
8:30 - +0830 1980 May
8:00 PRC C%sT
# far west China
Zone Asia/Kashgar 5:03:56 - LMT 1928 # or Kashi or Kaxgar
5:30 - +0530 1940
5:00 - +05 1980 May
8:00 PRC C%sT
# Kuwait
Zone Asia/Kuwait 3:11:56 - LMT 1950
3:00 - +03
# Oman
# Milne says 3:54:24 was the meridian of the Muscat Tidal Observatory.
Zone Asia/Muscat 3:54:24 - LMT 1920
4:00 - +04
# India
# From Paul Eggert (2014-08-11), after a heads-up from Stephen Colebourne:
# According to a Portuguese decree (1911-05-26)
# https://dre.pt/pdf1sdip/1911/05/12500/23132313.pdf
# Portuguese India switched to UT +05 on 1912-01-01.
#Zone Asia/Panaji [not enough info to complete]
# Cambodia
-# From Paul Eggert (2014-10-11):
-# See Asia/Ho_Chi_Minh for the source for most of this data. Also, guess
-# (1) Cambodia reverted to UT +07 on 1945-09-02, when Vietnam did, and
-# (2) they also reverted to +07 on 1953-11-09, the date of independence.
-# These guesses are probably wrong but they're better than guessing no
-# transitions there.
+
+# From an adoptive daughter of the late Cambodian ruler Prince Sihanouk,
+# via Alois Treindl (2019-08-08):
+#
+# King Sihanouk said that, during the Japanese occupation, starting with
+# what historians refer to as "le coup de force du 9 mars 1945", Cambodia,
+# like the entire French Indochina, used Tokyo time zone. After Japan
+# surrendered, 2 September 1945, Cambodia fell under French rule again and
+# adopted Hanoi time zone again.
+#
+# However, on 7 January 1946, Sihanouk and Tioulong managed to obtain a
+# status of "internal autonomy" from the government of Charles de Gaulle.
+# Although many fields remained under the administration of the French
+# (customs, taxes, justice, defence, foreign affairs, etc.), the Cambodian
+# administration was responsible for religious matters and traditional
+# celebrations, which included our calendar and time. The time zone was GMT
+# + 7 and _no_ DST was applied.
+#
+# After Sihanouk and Tioulong achieved full independence, on 9 November 1953,
+# GMT + 7 was maintained.
+
+# From Paul Eggert (2019-08-26):
+# See Asia/Ho_Chi_Minh for the source for most of rest of this data.
+
Zone Asia/Phnom_Penh 6:59:40 - LMT 1906 Jul 1
7:06:30 - PLMT 1911 May 1
7:00 - +07 1942 Dec 31 23:00
8:00 - +08 1945 Mar 14 23:00
9:00 - +09 1945 Sep 2
- 7:00 - +07 1947 Apr 1
- 8:00 - +08 1953 Nov 9
7:00 - +07
# Israel
Zone Asia/Tel_Aviv 2:19:04 - LMT 1880
2:21 - JMT 1918
2:00 Zion I%sT
# Laos
# From Paul Eggert (2014-10-11):
# See Asia/Ho_Chi_Minh for the source for most of this data.
# Trần's book says that Laos reverted to UT +07 on 1955-04-15.
# Also, guess that Laos reverted to +07 on 1945-09-02, when Vietnam did;
# this is probably wrong but it's better than guessing no transition.
Zone Asia/Vientiane 6:50:24 - LMT 1906 Jul 1
7:06:30 - PLMT 1911 May 1
7:00 - +07 1942 Dec 31 23:00
8:00 - +08 1945 Mar 14 23:00
9:00 - +09 1945 Sep 2
7:00 - +07 1947 Apr 1
8:00 - +08 1955 Apr 15
7:00 - +07
# Jan Mayen
# From Whitman:
Zone Atlantic/Jan_Mayen -1:00 - -01
# St Helena
Zone Atlantic/St_Helena -0:22:48 - LMT 1890 # Jamestown
-0:22:48 - JMT 1951 # Jamestown Mean Time
0:00 - GMT
# Northern Ireland
Zone Europe/Belfast -0:23:40 - LMT 1880 Aug 2
-0:25:21 - DMT 1916 May 21 2:00
# DMT = Dublin/Dunsink MT
-0:25:21 1:00 IST 1916 Oct 1 2:00s
# IST = Irish Summer Time
0:00 GB-Eire %s 1968 Oct 27
1:00 - BST 1971 Oct 31 2:00u
0:00 GB-Eire %s 1996
0:00 EU GMT/BST
# Guernsey
# Data from Joseph S. Myers
# https://mm.icann.org/pipermail/tz/2013-September/019883.html
# References to be added
# LMT is for Town Church, St. Peter Port, 49° 27' 17" N, 2° 32' 10" W.
Zone Europe/Guernsey -0:10:09 - LMT 1913 Jun 18
0:00 GB-Eire %s 1940 Jul 2
1:00 C-Eur CE%sT 1945 May 8
0:00 GB-Eire %s 1968 Oct 27
1:00 - BST 1971 Oct 31 2:00u
0:00 GB-Eire %s 1996
0:00 EU GMT/BST
# Isle of Man
#
# From Lester Caine (2013-09-04):
# The Isle of Man legislation is now on-line at
# <https://www.legislation.gov.im>, starting with the original Statutory
# Time Act in 1883 and including additional confirmation of some of
# the dates of the 'Summer Time' orders originating at
# Westminster. There is a little uncertainty as to the starting date
# of the first summer time in 1916 which may have been announced a
# couple of days late. There is still a substantial number of
# documents to work through, but it is thought that every GB change
# was also implemented on the island.
#
# AT4 of 1883 - The Statutory Time et cetera Act 1883 -
# LMT Location - 54.1508N -4.4814E - Tynwald Hill ( Manx parliament )
Zone Europe/Isle_of_Man -0:17:55 - LMT 1883 Mar 30 0:00s
0:00 GB-Eire %s 1968 Oct 27
1:00 - BST 1971 Oct 31 2:00u
0:00 GB-Eire %s 1996
0:00 EU GMT/BST
# Jersey
# Data from Joseph S. Myers
# https://mm.icann.org/pipermail/tz/2013-September/019883.html
# References to be added
# LMT is for Parish Church, St. Helier, 49° 11' 0.57" N, 2° 6' 24.33" W.
Zone Europe/Jersey -0:08:26 - LMT 1898 Jun 11 16:00u
0:00 GB-Eire %s 1940 Jul 2
1:00 C-Eur CE%sT 1945 May 8
0:00 GB-Eire %s 1968 Oct 27
1:00 - BST 1971 Oct 31 2:00u
0:00 GB-Eire %s 1996
0:00 EU GMT/BST
# Slovenia
Zone Europe/Ljubljana 0:58:04 - LMT 1884
1:00 - CET 1941 Apr 18 23:00
1:00 C-Eur CE%sT 1945 May 8 2:00s
1:00 1:00 CEST 1945 Sep 16 2:00s
1:00 - CET 1982 Nov 27
1:00 EU CE%sT
# Bosnia and Herzegovina
Zone Europe/Sarajevo 1:13:40 - LMT 1884
1:00 - CET 1941 Apr 18 23:00
1:00 C-Eur CE%sT 1945 May 8 2:00s
1:00 1:00 CEST 1945 Sep 16 2:00s
1:00 - CET 1982 Nov 27
1:00 EU CE%sT
# North Macedonia
Zone Europe/Skopje 1:25:44 - LMT 1884
1:00 - CET 1941 Apr 18 23:00
1:00 C-Eur CE%sT 1945 May 8 2:00s
1:00 1:00 CEST 1945 Sep 16 2:00s
1:00 - CET 1982 Nov 27
1:00 EU CE%sT
# Moldova / Transnistria
Zone Europe/Tiraspol 1:58:32 - LMT 1880
1:55 - CMT 1918 Feb 15 # Chisinau MT
1:44:24 - BMT 1931 Jul 24 # Bucharest MT
2:00 Romania EE%sT 1940 Aug 15
2:00 1:00 EEST 1941 Jul 17
1:00 C-Eur CE%sT 1944 Aug 24
3:00 Russia MSK/MSD 1991 Mar 31 2:00
2:00 Russia EE%sT 1992 Jan 19 2:00
3:00 Russia MSK/MSD
# Liechtenstein
Zone Europe/Vaduz 0:38:04 - LMT 1894 Jun
- 1:00 - CET 1981
+ 1:00 Swiss CE%sT 1981
1:00 EU CE%sT
# Croatia
Zone Europe/Zagreb 1:03:52 - LMT 1884
1:00 - CET 1941 Apr 18 23:00
1:00 C-Eur CE%sT 1945 May 8 2:00s
1:00 1:00 CEST 1945 Sep 16 2:00s
1:00 - CET 1982 Nov 27
1:00 EU CE%sT
# Madagascar
Zone Indian/Antananarivo 3:10:04 - LMT 1911 Jul
3:00 - EAT 1954 Feb 27 23:00s
3:00 1:00 EAST 1954 May 29 23:00s
3:00 - EAT
# Comoros
Zone Indian/Comoro 2:53:04 - LMT 1911 Jul # Moroni, Gran Comoro
3:00 - EAT
# Mayotte
Zone Indian/Mayotte 3:00:56 - LMT 1911 Jul # Mamoutzou
3:00 - EAT
# US minor outlying islands
Zone Pacific/Johnston -10:00 - HST
# US minor outlying islands
#
# From Mark Brader (2005-01-23):
# [Fallacies and Fantasies of Air Transport History, by R.E.G. Davies,
# published 1994 by Paladwr Press, McLean, VA, USA; ISBN 0-9626483-5-3]
# reproduced a Pan American Airways timetable from 1936, for their weekly
# "Orient Express" flights between San Francisco and Manila, and connecting
# flights to Chicago and the US East Coast. As it uses some time zone
# designations that I've never seen before:....
# Fri. 6:30A Lv. HONOLOLU (Pearl Harbor), H.I. H.L.T. Ar. 5:30P Sun.
# " 3:00P Ar. MIDWAY ISLAND . . . . . . . . . M.L.T. Lv. 6:00A "
#
Zone Pacific/Midway -11:49:28 - LMT 1901
-11:00 - -11 1956 Jun 3
-11:00 1:00 -10 1956 Sep 2
-11:00 - -11
# N Mariana Is
Zone Pacific/Saipan -14:17:00 - LMT 1844 Dec 31
9:43:00 - LMT 1901
9:00 - +09 1969 Oct
10:00 - +10 2000 Dec 23
10:00 - ChST # Chamorro Standard Time
Index: stable/12/contrib/tzdata/europe
===================================================================
--- stable/12/contrib/tzdata/europe (revision 352352)
+++ stable/12/contrib/tzdata/europe (revision 352353)
@@ -1,4007 +1,4085 @@
# tzdb data for Europe and environs
# This file is in the public domain, so clarified as of
# 2009-05-17 by Arthur David Olson.
# This file is by no means authoritative; if you think you know better,
# go ahead and edit the file (and please send any changes to
# tz@iana.org for general use in the future). For more, please see
# the file CONTRIBUTING in the tz distribution.
# From Paul Eggert (2017-02-10):
#
# Unless otherwise specified, the source for data through 1990 is:
# Thomas G. Shanks and Rique Pottenger, The International Atlas (6th edition),
# San Diego: ACS Publications, Inc. (2003).
# Unfortunately this book contains many errors and cites no sources.
#
# Many years ago Gwillim Law wrote that a good source
# for time zone data was the International Air Transport
# Association's Standard Schedules Information Manual (IATA SSIM),
# published semiannually. Law sent in several helpful summaries
# of the IATA's data after 1990. Except where otherwise noted,
# IATA SSIM is the source for entries after 1990.
#
# A reliable and entertaining source about time zones is
# Derek Howse, Greenwich time and longitude, Philip Wilson Publishers (1997).
#
# Except where otherwise noted, Shanks & Pottenger is the source for
# entries through 1991, and IATA SSIM is the source for entries afterwards.
#
# Other sources occasionally used include:
#
# Edward W. Whitman, World Time Differences,
# Whitman Publishing Co, 2 Niagara Av, Ealing, London (undated),
# which I found in the UCLA library.
#
# William Willett, The Waste of Daylight, 19th edition
# <http://cs.ucla.edu/~eggert/The-Waste-of-Daylight-19th.pdf>
# [PDF] (1914-03)
#
# Milne J. Civil time. Geogr J. 1899 Feb;13(2):173-94
# <https://www.jstor.org/stable/1774359>. He writes:
# "It is requested that corrections and additions to these tables
# may be sent to Mr. John Milne, Royal Geographical Society,
# Savile Row, London." Nowadays please email them to tz@iana.org.
#
# Byalokoz EL. New Counting of Time in Russia since July 1, 1919.
# This Russian-language source was consulted by Vladimir Karpinsky; see
# https://mm.icann.org/pipermail/tz/2014-August/021320.html
# The full Russian citation is:
# Бялокоз, Евгений Людвигович. Новый счет времени в течении суток
# введенный декретом Совета народных комиссаров для всей России с 1-го
# июля 1919 г. / Изд. 2-е Междуведомственной комиссии. - Петроград:
# Десятая гос. тип., 1919.
# http://resolver.gpntb.ru/purl?docushare/dsweb/Get/Resource-2011/Byalokoz__E.L.__Novyy__schet__vremeni__v__techenie__sutok__izd__2(1).pdf
#
# Brazil's Divisão Serviço da Hora (DSHO),
# History of Summer Time
# <http://pcdsh01.on.br/HISTHV.htm>
# (1998-09-21, in Portuguese)
#
# I invented the abbreviations marked '*' in the following table;
# the rest are variants of the "xMT" pattern for a city's mean time,
# or are from other sources. Corrections are welcome!
# std dst 2dst
# LMT Local Mean Time
# -4:00 AST ADT Atlantic
# 0:00 GMT BST BDST Greenwich, British Summer
# 0:00 GMT IST Greenwich, Irish Summer
# 0:00 WET WEST WEMT Western Europe
# 0:19:32.13 AMT* NST* Amsterdam, Netherlands Summer (1835-1937)
# 1:00 BST British Standard (1968-1971)
# 1:00 IST GMT Irish Standard (1968-) with winter DST
# 1:00 CET CEST CEMT Central Europe
# 1:00:14 SET Swedish (1879-1899)
# 1:36:34 RMT* LST* Riga, Latvian Summer (1880-1926)*
# 2:00 EET EEST Eastern Europe
# 3:00 MSK MSD MDST* Moscow
# From Peter Ilieve (1994-12-04), re EEC/EC/EU members:
# The original six: Belgium, France, (West) Germany, Italy,
# Luxembourg, the Netherlands.
# Plus, from 1 Jan 73: Denmark, Ireland, United Kingdom.
# Plus, from 1 Jan 81: Greece.
# Plus, from 1 Jan 86: Spain, Portugal.
# Plus, from 1 Jan 95: Austria, Finland, Sweden. (Norway negotiated terms for
# entry but in a referendum on 28 Nov 94 the people voted No by 52.2% to 47.8%
# on a turnout of 88.6%. This was almost the same result as Norway's previous
# referendum in 1972, they are the only country to have said No twice.
# Referendums in the other three countries voted Yes.)
# ...
# Estonia ... uses EU dates but not at 01:00 GMT, they use midnight GMT.
# I don't think they know yet what they will do from 1996 onwards.
# ...
# There shouldn't be any [current members who are not using EU rules].
# A Directive has the force of law, member states are obliged to enact
# national law to implement it. The only contentious issue was the
# different end date for the UK and Ireland, and this was always allowed
# in the Directive.
###############################################################################
# Britain (United Kingdom) and Ireland (Eire)
# From Peter Ilieve (1994-07-06):
#
# On 17 Jan 1994 the Independent, a UK quality newspaper, had a piece about
# historical vistas along the Thames in west London. There was a photo
# and a sketch map showing some of the sightlines involved. One paragraph
# of the text said:
#
# 'An old stone obelisk marking a forgotten terrestrial meridian stands
# beside the river at Kew. In the 18th century, before time and longitude
# was standardised by the Royal Observatory in Greenwich, scholars observed
# this stone and the movement of stars from Kew Observatory nearby. They
# made their calculations and set the time for the Horse Guards and Parliament,
# but now the stone is obscured by scrubwood and can only be seen by walking
# along the towpath within a few yards of it.'
#
# I have a one inch to one mile map of London and my estimate of the stone's
# position is 51° 28' 30" N, 0° 18' 45" W. The longitude should
# be within about ±2". The Ordnance Survey grid reference is TQ172761.
#
# [This yields STDOFF = -0:01:15 for London LMT in the 18th century.]
# From Paul Eggert (1993-11-18):
#
# Howse writes that Britain was the first country to use standard time.
# The railways cared most about the inconsistencies of local mean time,
# and it was they who forced a uniform time on the country.
# The original idea was credited to Dr. William Hyde Wollaston (1766-1828)
# and was popularized by Abraham Follett Osler (1808-1903).
# The first railway to adopt London time was the Great Western Railway
# in November 1840; other railways followed suit, and by 1847 most
# (though not all) railways used London time. On 1847-09-22 the
# Railway Clearing House, an industry standards body, recommended that GMT be
# adopted at all stations as soon as the General Post Office permitted it.
# The transition occurred on 12-01 for the L&NW, the Caledonian,
# and presumably other railways; the January 1848 Bradshaw's lists many
# railways as using GMT. By 1855 the vast majority of public
# clocks in Britain were set to GMT (though some, like the great clock
# on Tom Tower at Christ Church, Oxford, were fitted with two minute hands,
# one for local time and one for GMT). The last major holdout was the legal
# system, which stubbornly stuck to local time for many years, leading
# to oddities like polls opening at 08:13 and closing at 16:13.
# The legal system finally switched to GMT when the Statutes (Definition
# of Time) Act took effect; it received the Royal Assent on 1880-08-02.
#
# In the tables below, we condense this complicated story into a single
# transition date for London, namely 1847-12-01. We don't know as much
# about Dublin, so we use 1880-08-02, the legal transition time.
# From Paul Eggert (2014-07-19):
# The ancients had no need for daylight saving, as they kept time
# informally or via hours whose length depended on the time of year.
# Daylight saving time in its modern sense was invented by the
# New Zealand entomologist George Vernon Hudson (1867-1946),
# whose day job as a postal clerk led him to value
# after-hours daylight in which to pursue his research.
# In 1895 he presented a paper to the Wellington Philosophical Society
# that proposed a two-hour daylight-saving shift. See:
# Hudson GV. On seasonal time-adjustment in countries south of lat. 30°.
# Transactions and Proceedings of the New Zealand Institute. 1895;28:734
# http://rsnz.natlib.govt.nz/volume/rsnz_28/rsnz_28_00_006110.html
# Although some interest was expressed in New Zealand, his proposal
# did not find its way into law and eventually it was almost forgotten.
#
# In England, DST was independently reinvented by William Willett (1857-1915),
# a London builder and member of the Royal Astronomical Society
# who circulated a pamphlet "The Waste of Daylight" (1907)
# that proposed advancing clocks 20 minutes on each of four Sundays in April,
# and retarding them by the same amount on four Sundays in September.
# A bill was drafted in 1909 and introduced in Parliament several times,
# but it met with ridicule and opposition, especially from farming interests.
# Later editions of the pamphlet proposed one-hour summer time, and
# it was eventually adopted as a wartime measure in 1916.
# See: Summer Time Arrives Early, The Times (2000-05-18).
# A monument to Willett was unveiled on 1927-05-21, in an open space in
# a 45-acre wood near Chislehurst, Kent that was purchased by popular
# subscription and open to the public. On the south face of the monolith,
# designed by G. W. Miller, is the William Willett Memorial Sundial,
# which is permanently set to Summer Time.
# From Winston Churchill (1934-04-28):
# It is one of the paradoxes of history that we should owe the boon of
# summer time, which gives every year to the people of this country
# between 160 and 170 hours more daylight leisure, to a war which
# plunged Europe into darkness for four years, and shook the
# foundations of civilization throughout the world.
# -- "A Silent Toast to William Willett", Pictorial Weekly;
# republished in Finest Hour (Spring 2002) 1(114):26
# https://www.winstonchurchill.org/publications/finest-hour/finest-hour-114/a-silent-toast-to-william-willett-by-winston-s-churchill
# From Paul Eggert (2015-08-08):
# The OED Supplement says that the English originally said "Daylight Saving"
# when they were debating the adoption of DST in 1908; but by 1916 this
# term appears only in quotes taken from DST's opponents, whereas the
# proponents (who eventually won the argument) are quoted as using "Summer".
# The term "Summer Time" was introduced by Herbert Samuel, Home Secretary; see:
# Viscount Samuel. Leisure in a Democracy. Cambridge University Press
# ISBN 978-1-107-49471-8 (1949, reissued 2015), p 8.
# From Arthur David Olson (1989-01-19):
# A source at the British Information Office in New York avers that it's
# known as "British" Summer Time in all parts of the United Kingdom.
# Date: 4 Jan 89 08:57:25 GMT (Wed)
# From: Jonathan Leffler
# [British Summer Time] is fixed annually by Act of Parliament.
# If you can predict what Parliament will do, you should be in
# politics making a fortune, not computing.
# From Chris Carrier (1996-06-14):
# I remember reading in various wartime issues of the London Times the
# acronym BDST for British Double Summer Time. Look for the published
# time of sunrise and sunset in The Times, when BDST was in effect, and
# if you find a zone reference it will say, "All times B.D.S.T."
# From Joseph S. Myers (1999-09-02):
# ... some military cables (WO 219/4100 - this is a copy from the
# main SHAEF archives held in the US National Archives, SHAEF/5252/8/516)
# agree that the usage is BDST (this appears in a message dated 17 Feb 1945).
# From Joseph S. Myers (2000-10-03):
# On 18th April 1941, Sir Stephen Tallents of the BBC wrote to Sir
# Alexander Maxwell of the Home Office asking whether there was any
# official designation; the reply of the 21st was that there wasn't
# but he couldn't think of anything better than the "Double British
# Summer Time" that the BBC had been using informally.
# https://www.polyomino.org.uk/british-time/bbc-19410418.png
# https://www.polyomino.org.uk/british-time/ho-19410421.png
# From Sir Alexander Maxwell in the above-mentioned letter (1941-04-21):
# [N]o official designation has as far as I know been adopted for the time
# which is to be introduced in May....
# I cannot think of anything better than "Double British Summer Time"
# which could not be said to run counter to any official description.
# From Paul Eggert (2000-10-02):
# Howse writes (p 157) 'DBST' too, but 'BDST' seems to have been common
# and follows the more usual convention of putting the location name first,
# so we use 'BDST'.
# Peter Ilieve (1998-04-19) described at length
# the history of summer time legislation in the United Kingdom.
# Since 1998 Joseph S. Myers has been updating
# and extending this list, which can be found in
# https://www.polyomino.org.uk/british-time/
# From Joseph S. Myers (1998-01-06):
#
# The legal time in the UK outside of summer time is definitely GMT, not UTC;
# see Lord Tanlaw's speech
# https://www.publications.parliament.uk/pa/ld199798/ldhansrd/vo970611/text/70611-10.htm#70611-10_head0
# (Lords Hansard 11 June 1997 columns 964 to 976).
# From Paul Eggert (2006-03-22):
#
# For lack of other data, follow Shanks & Pottenger for Eire in 1940-1948.
#
# Given Ilieve and Myers's data, the following claims by Shanks & Pottenger
# are incorrect:
# * Wales did not switch from GMT to daylight saving time until
# 1921 Apr 3, when they began to conform with the rest of Great Britain.
# Actually, Wales was identical after 1880.
# * Eire had two transitions on 1916 Oct 1.
# It actually just had one transition.
# * Northern Ireland used single daylight saving time throughout WW II.
# Actually, it conformed to Britain.
# * GB-Eire changed standard time to 1 hour ahead of GMT on 1968-02-18.
# Actually, that date saw the usual switch to summer time.
# Standard time was not changed until 1968-10-27 (the clocks didn't change).
#
# Here is another incorrect claim by Shanks & Pottenger:
# * Jersey, Guernsey, and the Isle of Man did not switch from GMT
# to daylight saving time until 1921 Apr 3, when they began to
# conform with Great Britain.
# S.R.&O. 1916, No. 382 and HO 45/10811/312364 (quoted above) say otherwise.
#
# The following claim by Shanks & Pottenger is possible though doubtful;
# we'll ignore it for now.
# * Dublin's 1971-10-31 switch was at 02:00, even though London's was 03:00.
# From Paul Eggert (2017-12-04):
#
# Dunsink Observatory (8 km NW of Dublin's center) was to Dublin as
# Greenwich was to London. For example:
#
# "Timeball on the ballast office is down. Dunsink time."
# -- James Joyce, Ulysses
#
# The abbreviation DMT stood for "Dublin Mean Time" or "Dunsink Mean Time";
# this being Ireland, opinions differed.
#
# Whitman says Dublin/Dunsink Mean Time was UT-00:25:21, which agrees
# with measurements of recent visitors to the Meridian Room of Dunsink
# Observatory; see Malone D. Dunsink and timekeeping. 2016-01-24.
# <https://www.maths.tcd.ie/~dwmalone/time/dunsink.html>. Malone
# writes that the Nautical Almanac listed UT-00:25:22 until 1896, when
# it moved to UT-00:25:21.1 (I confirmed that the 1893 edition used
# the former and the 1896 edition used the latter). Evidently the
# news of this change propagated slowly, as Milne 1899 still lists
# UT-00:25:22 and cites the International Telegraph Bureau. As it is
# not clear that there was any practical significance to the change
# from UT-00:25:22 to UT-00:25:21.1 in civil timekeeping, omit this
# transition for now and just use the latter value, omitting its
# fraction since our format cannot represent fractions.
# "Countess Markievicz ... claimed that the [1916] abolition of Dublin Mean Time
# was among various actions undertaken by the 'English' government that
# would 'put the whole country into the SF (Sinn Féin) camp'. She claimed
# Irish 'public feeling (was) outraged by forcing of English time on us'."
# -- Parsons M. Dublin lost its time zone - and 25 minutes - after 1916 Rising.
# Irish Times 2014-10-27.
# https://www.irishtimes.com/news/politics/dublin-lost-its-time-zone-and-25-minutes-after-1916-rising-1.1977411
# From Joseph S. Myers (2005-01-26):
# Irish laws are available online at <http://www.irishstatutebook.ie>.
# These include various relating to legal time, for example:
#
# ZZA13Y1923.html ZZA12Y1924.html ZZA8Y1925.html ZZSIV20PG1267.html
#
# ZZSI71Y1947.html ZZSI128Y1948.html ZZSI23Y1949.html ZZSI41Y1950.html
# ZZSI27Y1951.html ZZSI73Y1952.html
#
# ZZSI11Y1961.html ZZSI232Y1961.html ZZSI182Y1962.html
# ZZSI167Y1963.html ZZSI257Y1964.html ZZSI198Y1967.html
# ZZA23Y1968.html ZZA17Y1971.html
#
# ZZSI67Y1981.html ZZSI212Y1982.html ZZSI45Y1986.html
# ZZSI264Y1988.html ZZSI52Y1990.html ZZSI371Y1992.html
# ZZSI395Y1994.html ZZSI484Y1997.html ZZSI506Y2001.html
#
# [These are all relative to the root, e.g., the first is
# <http://www.irishstatutebook.ie/ZZA13Y1923.html>.]
#
# (These are those I found, but there could be more. In any case these
# should allow various updates to the comments in the europe file to cover
# the laws applicable in Ireland.)
#
# (Note that the time in the Republic of Ireland since 1968 has been defined
# in terms of standard time being GMT+1 with a period of winter time when it
# is GMT, rather than standard time being GMT with a period of summer time
# being GMT+1.)
# From Paul Eggert (1999-03-28):
# Clive Feather (<news:859845706.26043.0@office.demon.net>, 1997-03-31)
# reports that Folkestone (Cheriton) Shuttle Terminal uses Concession Time
# (CT), equivalent to French civil time.
# Julian Hill (<news:36118128.5A14@virgin.net>, 1998-09-30) reports that
# trains between Dollands Moor (the freight facility next door)
# and Frethun run in CT.
# My admittedly uninformed guess is that the terminal has two authorities,
# the French concession operators and the British civil authorities,
# and that the time depends on who you're talking to.
# If, say, the British police were called to the station for some reason,
# I would expect the official police report to use GMT/BST and not CET/CEST.
# This is a borderline case, but for now let's stick to GMT/BST.
# From an anonymous contributor (1996-06-02):
# The law governing time in Ireland is under Statutory Instrument SI 395/94,
# which gives force to European Union 7th Council Directive No. 94/21/EC.
# Under this directive, the Minister for Justice in Ireland makes appropriate
# regulations. I spoke this morning with the Secretary of the Department of
# Justice (tel +353 1 678 9711) who confirmed to me that the correct name is
# "Irish Summer Time", abbreviated to "IST".
#
# From Paul Eggert (2017-12-07):
# The 1996 anonymous contributor's goal was to determine the correct
# abbreviation for summer time in Dublin and so the contributor
# focused on the "IST", not on the "Irish Summer Time". Though the
# "IST" was correct, the "Irish Summer Time" appears to have been an
# error, as Ireland's Standard Time (Amendment) Act, 1971 states that
# standard time in Ireland remains at UT +01 and is observed in
# summer, and that Greenwich mean time is observed in winter. (Thanks
# to Derick Rethans for pointing out the error.) That is, when
# Ireland amended the 1968 act that established UT +01 as Irish
# Standard Time, it left standard time unchanged and established GMT
# as a negative daylight saving time in winter. So, in this database
# IST stands for Irish Summer Time for timestamps before 1968, and for
# Irish Standard Time after that. See:
# http://www.irishstatutebook.ie/eli/1971/act/17/enacted/en/print
# Michael Deckers (2017-06-01) gave the following URLs for Ireland's
# Summer Time Act, 1925 and Summer Time Orders, 1926 and 1947:
# http://www.irishstatutebook.ie/eli/1925/act/8/enacted/en/print
# http://www.irishstatutebook.ie/eli/1926/sro/919/made/en/print
# http://www.irishstatutebook.ie/eli/1947/sro/71/made/en/print
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
# Summer Time Act, 1916
Rule GB-Eire 1916 only - May 21 2:00s 1:00 BST
Rule GB-Eire 1916 only - Oct 1 2:00s 0 GMT
# S.R.&O. 1917, No. 358
Rule GB-Eire 1917 only - Apr 8 2:00s 1:00 BST
Rule GB-Eire 1917 only - Sep 17 2:00s 0 GMT
# S.R.&O. 1918, No. 274
Rule GB-Eire 1918 only - Mar 24 2:00s 1:00 BST
Rule GB-Eire 1918 only - Sep 30 2:00s 0 GMT
# S.R.&O. 1919, No. 297
Rule GB-Eire 1919 only - Mar 30 2:00s 1:00 BST
Rule GB-Eire 1919 only - Sep 29 2:00s 0 GMT
# S.R.&O. 1920, No. 458
Rule GB-Eire 1920 only - Mar 28 2:00s 1:00 BST
# S.R.&O. 1920, No. 1844
Rule GB-Eire 1920 only - Oct 25 2:00s 0 GMT
# S.R.&O. 1921, No. 363
Rule GB-Eire 1921 only - Apr 3 2:00s 1:00 BST
Rule GB-Eire 1921 only - Oct 3 2:00s 0 GMT
# S.R.&O. 1922, No. 264
Rule GB-Eire 1922 only - Mar 26 2:00s 1:00 BST
Rule GB-Eire 1922 only - Oct 8 2:00s 0 GMT
# The Summer Time Act, 1922
Rule GB-Eire 1923 only - Apr Sun>=16 2:00s 1:00 BST
Rule GB-Eire 1923 1924 - Sep Sun>=16 2:00s 0 GMT
Rule GB-Eire 1924 only - Apr Sun>=9 2:00s 1:00 BST
Rule GB-Eire 1925 1926 - Apr Sun>=16 2:00s 1:00 BST
# The Summer Time Act, 1925
Rule GB-Eire 1925 1938 - Oct Sun>=2 2:00s 0 GMT
Rule GB-Eire 1927 only - Apr Sun>=9 2:00s 1:00 BST
Rule GB-Eire 1928 1929 - Apr Sun>=16 2:00s 1:00 BST
Rule GB-Eire 1930 only - Apr Sun>=9 2:00s 1:00 BST
Rule GB-Eire 1931 1932 - Apr Sun>=16 2:00s 1:00 BST
Rule GB-Eire 1933 only - Apr Sun>=9 2:00s 1:00 BST
Rule GB-Eire 1934 only - Apr Sun>=16 2:00s 1:00 BST
Rule GB-Eire 1935 only - Apr Sun>=9 2:00s 1:00 BST
Rule GB-Eire 1936 1937 - Apr Sun>=16 2:00s 1:00 BST
Rule GB-Eire 1938 only - Apr Sun>=9 2:00s 1:00 BST
Rule GB-Eire 1939 only - Apr Sun>=16 2:00s 1:00 BST
# S.R.&O. 1939, No. 1379
Rule GB-Eire 1939 only - Nov Sun>=16 2:00s 0 GMT
# S.R.&O. 1940, No. 172 and No. 1883
Rule GB-Eire 1940 only - Feb Sun>=23 2:00s 1:00 BST
# S.R.&O. 1941, No. 476
Rule GB-Eire 1941 only - May Sun>=2 1:00s 2:00 BDST
Rule GB-Eire 1941 1943 - Aug Sun>=9 1:00s 1:00 BST
# S.R.&O. 1942, No. 506
Rule GB-Eire 1942 1944 - Apr Sun>=2 1:00s 2:00 BDST
# S.R.&O. 1944, No. 932
Rule GB-Eire 1944 only - Sep Sun>=16 1:00s 1:00 BST
# S.R.&O. 1945, No. 312
Rule GB-Eire 1945 only - Apr Mon>=2 1:00s 2:00 BDST
Rule GB-Eire 1945 only - Jul Sun>=9 1:00s 1:00 BST
# S.R.&O. 1945, No. 1208
Rule GB-Eire 1945 1946 - Oct Sun>=2 2:00s 0 GMT
Rule GB-Eire 1946 only - Apr Sun>=9 2:00s 1:00 BST
# The Summer Time Act, 1947
Rule GB-Eire 1947 only - Mar 16 2:00s 1:00 BST
Rule GB-Eire 1947 only - Apr 13 1:00s 2:00 BDST
Rule GB-Eire 1947 only - Aug 10 1:00s 1:00 BST
Rule GB-Eire 1947 only - Nov 2 2:00s 0 GMT
# Summer Time Order, 1948 (S.I. 1948/495)
Rule GB-Eire 1948 only - Mar 14 2:00s 1:00 BST
Rule GB-Eire 1948 only - Oct 31 2:00s 0 GMT
# Summer Time Order, 1949 (S.I. 1949/373)
Rule GB-Eire 1949 only - Apr 3 2:00s 1:00 BST
Rule GB-Eire 1949 only - Oct 30 2:00s 0 GMT
# Summer Time Order, 1950 (S.I. 1950/518)
# Summer Time Order, 1951 (S.I. 1951/430)
# Summer Time Order, 1952 (S.I. 1952/451)
Rule GB-Eire 1950 1952 - Apr Sun>=14 2:00s 1:00 BST
Rule GB-Eire 1950 1952 - Oct Sun>=21 2:00s 0 GMT
# revert to the rules of the Summer Time Act, 1925
Rule GB-Eire 1953 only - Apr Sun>=16 2:00s 1:00 BST
Rule GB-Eire 1953 1960 - Oct Sun>=2 2:00s 0 GMT
Rule GB-Eire 1954 only - Apr Sun>=9 2:00s 1:00 BST
Rule GB-Eire 1955 1956 - Apr Sun>=16 2:00s 1:00 BST
Rule GB-Eire 1957 only - Apr Sun>=9 2:00s 1:00 BST
Rule GB-Eire 1958 1959 - Apr Sun>=16 2:00s 1:00 BST
Rule GB-Eire 1960 only - Apr Sun>=9 2:00s 1:00 BST
# Summer Time Order, 1961 (S.I. 1961/71)
# Summer Time (1962) Order, 1961 (S.I. 1961/2465)
# Summer Time Order, 1963 (S.I. 1963/81)
Rule GB-Eire 1961 1963 - Mar lastSun 2:00s 1:00 BST
Rule GB-Eire 1961 1968 - Oct Sun>=23 2:00s 0 GMT
# Summer Time (1964) Order, 1963 (S.I. 1963/2101)
# Summer Time Order, 1964 (S.I. 1964/1201)
# Summer Time Order, 1967 (S.I. 1967/1148)
Rule GB-Eire 1964 1967 - Mar Sun>=19 2:00s 1:00 BST
# Summer Time Order, 1968 (S.I. 1968/117)
Rule GB-Eire 1968 only - Feb 18 2:00s 1:00 BST
# The British Standard Time Act, 1968
# (no summer time)
# The Summer Time Act, 1972
Rule GB-Eire 1972 1980 - Mar Sun>=16 2:00s 1:00 BST
Rule GB-Eire 1972 1980 - Oct Sun>=23 2:00s 0 GMT
# Summer Time Order, 1980 (S.I. 1980/1089)
# Summer Time Order, 1982 (S.I. 1982/1673)
# Summer Time Order, 1986 (S.I. 1986/223)
# Summer Time Order, 1988 (S.I. 1988/931)
Rule GB-Eire 1981 1995 - Mar lastSun 1:00u 1:00 BST
Rule GB-Eire 1981 1989 - Oct Sun>=23 1:00u 0 GMT
# Summer Time Order, 1989 (S.I. 1989/985)
# Summer Time Order, 1992 (S.I. 1992/1729)
# Summer Time Order 1994 (S.I. 1994/2798)
Rule GB-Eire 1990 1995 - Oct Sun>=22 1:00u 0 GMT
# Summer Time Order 1997 (S.I. 1997/2982)
# See EU for rules starting in 1996.
#
# Use Europe/London for Jersey, Guernsey, and the Isle of Man.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/London -0:01:15 - LMT 1847 Dec 1 0:00s
0:00 GB-Eire %s 1968 Oct 27
1:00 - BST 1971 Oct 31 2:00u
0:00 GB-Eire %s 1996
0:00 EU GMT/BST
Link Europe/London Europe/Jersey
Link Europe/London Europe/Guernsey
Link Europe/London Europe/Isle_of_Man
# From Paul Eggert (2018-02-15):
# In January 2018 we discovered that the negative SAVE values in the
# Eire rules cause problems with tests for ICU:
# https://mm.icann.org/pipermail/tz/2018-January/025825.html
# and with tests for OpenJDK:
# https://mm.icann.org/pipermail/tz/2018-January/025822.html
#
# To work around this problem, the build procedure can translate the
# following data into two forms, one with negative SAVE values and the
# other form with a traditional approximation for Irish timestamps
# after 1971-10-31 02:00 UTC; although this approximation has tm_isdst
# flags that are reversed, its UTC offsets are correct and this often
# suffices. This source file currently uses only nonnegative SAVE
# values, but this is intended to change and downstream code should
# not rely on it.
#
# The following is like GB-Eire and EU, except with standard time in
# summer and negative daylight saving time in winter. It is for when
# negative SAVE values are used.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Eire 1971 only - Oct 31 2:00u -1:00 -
Rule Eire 1972 1980 - Mar Sun>=16 2:00u 0 -
Rule Eire 1972 1980 - Oct Sun>=23 2:00u -1:00 -
Rule Eire 1981 max - Mar lastSun 1:00u 0 -
Rule Eire 1981 1989 - Oct Sun>=23 1:00u -1:00 -
Rule Eire 1990 1995 - Oct Sun>=22 1:00u -1:00 -
Rule Eire 1996 max - Oct lastSun 1:00u -1:00 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Dublin -0:25:00 - LMT 1880 Aug 2
-0:25:21 - DMT 1916 May 21 2:00s
-0:25:21 1:00 IST 1916 Oct 1 2:00s
0:00 GB-Eire %s 1921 Dec 6 # independence
0:00 GB-Eire GMT/IST 1940 Feb 25 2:00s
0:00 1:00 IST 1946 Oct 6 2:00s
0:00 - GMT 1947 Mar 16 2:00s
0:00 1:00 IST 1947 Nov 2 2:00s
0:00 - GMT 1948 Apr 18 2:00s
0:00 GB-Eire GMT/IST 1968 Oct 27
# The next line is for when negative SAVE values are used.
1:00 Eire IST/GMT
# These three lines are for when SAVE values are always nonnegative.
# 1:00 - IST 1971 Oct 31 2:00u
# 0:00 GB-Eire GMT/IST 1996
# 0:00 EU GMT/IST
###############################################################################
# Europe
# The following rules are for the European Union and for its
# predecessor organization, the European Communities.
# For brevity they are called "EU rules" elsewhere in this file.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule EU 1977 1980 - Apr Sun>=1 1:00u 1:00 S
Rule EU 1977 only - Sep lastSun 1:00u 0 -
Rule EU 1978 only - Oct 1 1:00u 0 -
Rule EU 1979 1995 - Sep lastSun 1:00u 0 -
Rule EU 1981 max - Mar lastSun 1:00u 1:00 S
Rule EU 1996 max - Oct lastSun 1:00u 0 -
# The most recent directive covers the years starting in 2002. See:
# Directive 2000/84/EC of the European Parliament and of the Council
# of 19 January 2001 on summer-time arrangements.
# http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:32000L0084:EN:NOT
# W-Eur differs from EU only in that W-Eur uses standard time.
Rule W-Eur 1977 1980 - Apr Sun>=1 1:00s 1:00 S
Rule W-Eur 1977 only - Sep lastSun 1:00s 0 -
Rule W-Eur 1978 only - Oct 1 1:00s 0 -
Rule W-Eur 1979 1995 - Sep lastSun 1:00s 0 -
Rule W-Eur 1981 max - Mar lastSun 1:00s 1:00 S
Rule W-Eur 1996 max - Oct lastSun 1:00s 0 -
# Older C-Eur rules are for convenience in the tables.
# From 1977 on, C-Eur differs from EU only in that C-Eur uses standard time.
Rule C-Eur 1916 only - Apr 30 23:00 1:00 S
Rule C-Eur 1916 only - Oct 1 1:00 0 -
Rule C-Eur 1917 1918 - Apr Mon>=15 2:00s 1:00 S
Rule C-Eur 1917 1918 - Sep Mon>=15 2:00s 0 -
Rule C-Eur 1940 only - Apr 1 2:00s 1:00 S
Rule C-Eur 1942 only - Nov 2 2:00s 0 -
Rule C-Eur 1943 only - Mar 29 2:00s 1:00 S
Rule C-Eur 1943 only - Oct 4 2:00s 0 -
Rule C-Eur 1944 1945 - Apr Mon>=1 2:00s 1:00 S
# Whitman gives 1944 Oct 7; go with Shanks & Pottenger.
Rule C-Eur 1944 only - Oct 2 2:00s 0 -
# From Jesper Nørgaard Welen (2008-07-13):
#
# I found what is probably a typo of 2:00 which should perhaps be 2:00s
# in the C-Eur rule from tz database version 2008d (this part was
# corrected in version 2008d). The circumstantial evidence is simply the
# tz database itself, as seen below:
#
# Zone Europe/Paris 0:09:21 - LMT 1891 Mar 15 0:01
# 0:00 France WE%sT 1945 Sep 16 3:00
#
# Zone Europe/Monaco 0:29:32 - LMT 1891 Mar 15
# 0:00 France WE%sT 1945 Sep 16 3:00
#
# Zone Europe/Belgrade 1:22:00 - LMT 1884
# 1:00 1:00 CEST 1945 Sep 16 2:00s
#
# Rule France 1945 only - Sep 16 3:00 0 -
# Rule Belgium 1945 only - Sep 16 2:00s 0 -
# Rule Neth 1945 only - Sep 16 2:00s 0 -
#
# The rule line to be changed is:
#
# Rule C-Eur 1945 only - Sep 16 2:00 0 -
#
# It seems that Paris, Monaco, Rule France, Rule Belgium all agree on
# 2:00 standard time, e.g. 3:00 local time. However there are no
# countries that use C-Eur rules in September 1945, so the only items
# affected are apparently these fictitious zones that translate acronyms
# CET and MET:
#
# Zone CET 1:00 C-Eur CE%sT
# Zone MET 1:00 C-Eur ME%sT
#
# It this is right then the corrected version would look like:
#
# Rule C-Eur 1945 only - Sep 16 2:00s 0 -
#
# A small step for mankind though 8-)
Rule C-Eur 1945 only - Sep 16 2:00s 0 -
Rule C-Eur 1977 1980 - Apr Sun>=1 2:00s 1:00 S
Rule C-Eur 1977 only - Sep lastSun 2:00s 0 -
Rule C-Eur 1978 only - Oct 1 2:00s 0 -
Rule C-Eur 1979 1995 - Sep lastSun 2:00s 0 -
Rule C-Eur 1981 max - Mar lastSun 2:00s 1:00 S
Rule C-Eur 1996 max - Oct lastSun 2:00s 0 -
# E-Eur differs from EU only in that E-Eur switches at midnight local time.
Rule E-Eur 1977 1980 - Apr Sun>=1 0:00 1:00 S
Rule E-Eur 1977 only - Sep lastSun 0:00 0 -
Rule E-Eur 1978 only - Oct 1 0:00 0 -
Rule E-Eur 1979 1995 - Sep lastSun 0:00 0 -
Rule E-Eur 1981 max - Mar lastSun 0:00 1:00 S
Rule E-Eur 1996 max - Oct lastSun 0:00 0 -
# Daylight saving time for Russia and the Soviet Union
#
# The 1917-1921 decree URLs are from Alexander Belopolsky (2016-08-23).
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Russia 1917 only - Jul 1 23:00 1:00 MST # Moscow Summer Time
#
# Decree No. 142 (1917-12-22) http://istmat.info/node/28137
Rule Russia 1917 only - Dec 28 0:00 0 MMT # Moscow Mean Time
#
# Decree No. 497 (1918-05-30) http://istmat.info/node/30001
Rule Russia 1918 only - May 31 22:00 2:00 MDST # Moscow Double Summer Time
Rule Russia 1918 only - Sep 16 1:00 1:00 MST
#
# Decree No. 258 (1919-05-29) http://istmat.info/node/37949
Rule Russia 1919 only - May 31 23:00 2:00 MDST
#
Rule Russia 1919 only - Jul 1 0:00u 1:00 MSD
Rule Russia 1919 only - Aug 16 0:00 0 MSK
#
# Decree No. 63 (1921-02-03) http://istmat.info/node/45840
Rule Russia 1921 only - Feb 14 23:00 1:00 MSD
#
# Decree No. 121 (1921-03-07) http://istmat.info/node/45949
Rule Russia 1921 only - Mar 20 23:00 2:00 +05
#
Rule Russia 1921 only - Sep 1 0:00 1:00 MSD
Rule Russia 1921 only - Oct 1 0:00 0 -
# Act No. 925 of the Council of Ministers of the USSR (1980-10-24):
Rule Russia 1981 1984 - Apr 1 0:00 1:00 S
Rule Russia 1981 1983 - Oct 1 0:00 0 -
# Act No. 967 of the Council of Ministers of the USSR (1984-09-13), repeated in
# Act No. 227 of the Council of Ministers of the USSR (1989-03-14):
Rule Russia 1984 1995 - Sep lastSun 2:00s 0 -
Rule Russia 1985 2010 - Mar lastSun 2:00s 1:00 S
#
Rule Russia 1996 2010 - Oct lastSun 2:00s 0 -
# As described below, Russia's 2014 change affects Zone data, not Rule data.
# From Stepan Golosunov (2016-03-07):
# Wikipedia and other sources refer to the Act of the Council of
# Ministers of the USSR from 1988-01-04 No. 5 and the Act of the
# Council of Ministers of the USSR from 1989-03-14 No. 227.
#
# I did not find full texts of these acts. For the 1989 one we have
# title at https://base.garant.ru/70754136/ :
# "About change in calculation of time on the territories of
# Lithuanian SSR, Latvian SSR and Estonian SSR, Astrakhan,
# Kaliningrad, Kirov, Kuybyshev, Ulyanovsk and Uralsk oblasts".
# And http://astrozet.net/files/Zones/DOC/RU/1980-925.txt appears to
# contain quotes from both acts: Since last Sunday of March 1988 rules
# of the second time belt are installed in Volgograd and Saratov
# oblasts. Since last Sunday of March 1989:
# a) Lithuanian SSR, Latvian SSR, Estonian SSR, Kaliningrad oblast:
# second time belt rules without extra hour (Moscow-1);
# b) Astrakhan, Kirov, Kuybyshev, Ulyanovsk oblasts: second time belt
# rules (Moscow time)
# c) Uralsk oblast: third time belt rules (Moscow+1).
# From Stepan Golosunov (2016-03-27):
# Unamended version of the act of the
# Government of the Russian Federation No. 23 from 08.01.1992
# http://pravo.gov.ru/proxy/ips/?docbody=&nd=102014034&rdk=0
# says that every year clocks were to be moved forward on last Sunday
# of March at 2 hours and moved backwards on last Sunday of September
# at 3 hours. It was amended in 1996 to replace September with October.
# From Alexander Krivenyshev (2011-06-14):
# According to Kremlin press service, Russian President Dmitry Medvedev
# signed a federal law "On calculation of time" on June 9, 2011.
# According to the law Russia is abolishing daylight saving time.
#
# Medvedev signed a law "On the Calculation of Time" (in russian):
# http://bmockbe.ru/events/?ID=7583
#
# Medvedev signed a law on the calculation of the time (in russian):
# https://www.regnum.ru/news/polit/1413906.html
# From Arthur David Olson (2011-06-15):
# Take "abolishing daylight saving time" to mean that time is now considered
# to be standard.
# These are for backward compatibility with older versions.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone WET 0:00 EU WE%sT
Zone CET 1:00 C-Eur CE%sT
Zone MET 1:00 C-Eur ME%sT
Zone EET 2:00 EU EE%sT
# Previous editions of this database used abbreviations like MET DST
# for Central European Summer Time, but this didn't agree with common usage.
# From Markus Kuhn (1996-07-12):
# The official German names ... are
#
# Mitteleuropäische Zeit (MEZ) = UTC+01:00
# Mitteleuropäische Sommerzeit (MESZ) = UTC+02:00
#
# as defined in the German Time Act (Gesetz über die Zeitbestimmung (ZeitG),
# 1978-07-25, Bundesgesetzblatt, Jahrgang 1978, Teil I, S. 1110-1111)....
# I wrote ... to the German Federal Physical-Technical Institution
#
# Physikalisch-Technische Bundesanstalt (PTB)
# Laboratorium 4.41 "Zeiteinheit"
# Postfach 3345
# D-38023 Braunschweig
# phone: +49 531 592-0
#
# ... I received today an answer letter from Dr. Peter Hetzel, head of the PTB
# department for time and frequency transmission. He explained that the
# PTB translates MEZ and MESZ into English as
#
# Central European Time (CET) = UTC+01:00
# Central European Summer Time (CEST) = UTC+02:00
# Albania
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Albania 1940 only - Jun 16 0:00 1:00 S
Rule Albania 1942 only - Nov 2 3:00 0 -
Rule Albania 1943 only - Mar 29 2:00 1:00 S
Rule Albania 1943 only - Apr 10 3:00 0 -
Rule Albania 1974 only - May 4 0:00 1:00 S
Rule Albania 1974 only - Oct 2 0:00 0 -
Rule Albania 1975 only - May 1 0:00 1:00 S
Rule Albania 1975 only - Oct 2 0:00 0 -
Rule Albania 1976 only - May 2 0:00 1:00 S
Rule Albania 1976 only - Oct 3 0:00 0 -
Rule Albania 1977 only - May 8 0:00 1:00 S
Rule Albania 1977 only - Oct 2 0:00 0 -
Rule Albania 1978 only - May 6 0:00 1:00 S
Rule Albania 1978 only - Oct 1 0:00 0 -
Rule Albania 1979 only - May 5 0:00 1:00 S
Rule Albania 1979 only - Sep 30 0:00 0 -
Rule Albania 1980 only - May 3 0:00 1:00 S
Rule Albania 1980 only - Oct 4 0:00 0 -
Rule Albania 1981 only - Apr 26 0:00 1:00 S
Rule Albania 1981 only - Sep 27 0:00 0 -
Rule Albania 1982 only - May 2 0:00 1:00 S
Rule Albania 1982 only - Oct 3 0:00 0 -
Rule Albania 1983 only - Apr 18 0:00 1:00 S
Rule Albania 1983 only - Oct 1 0:00 0 -
Rule Albania 1984 only - Apr 1 0:00 1:00 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Tirane 1:19:20 - LMT 1914
1:00 - CET 1940 Jun 16
1:00 Albania CE%sT 1984 Jul
1:00 EU CE%sT
# Andorra
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Andorra 0:06:04 - LMT 1901
0:00 - WET 1946 Sep 30
1:00 - CET 1985 Mar 31 2:00
1:00 EU CE%sT
# Austria
# Milne says Vienna time was 1:05:21.
# From Paul Eggert (2006-03-22): Shanks & Pottenger give 1918-06-16 and
# 1945-11-18, but the Austrian Federal Office of Metrology and
# Surveying (BEV) gives 1918-09-16 and for Vienna gives the "alleged"
# date of 1945-04-12 with no time. For the 1980-04-06 transition
# Shanks & Pottenger give 02:00, the BEV 00:00. Go with the BEV,
# and guess 02:00 for 1945-04-12.
+# From Alois Triendl (2019-07-22):
+# In 1946 the end of DST was on Monday, 7 October 1946, at 3:00 am.
+# Shanks had this right. Source: Die Weltpresse, 5. Oktober 1946, page 5.
+
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Austria 1920 only - Apr 5 2:00s 1:00 S
Rule Austria 1920 only - Sep 13 2:00s 0 -
Rule Austria 1946 only - Apr 14 2:00s 1:00 S
-Rule Austria 1946 1948 - Oct Sun>=1 2:00s 0 -
+Rule Austria 1946 only - Oct 7 2:00s 0 -
+Rule Austria 1947 1948 - Oct Sun>=1 2:00s 0 -
Rule Austria 1947 only - Apr 6 2:00s 1:00 S
Rule Austria 1948 only - Apr 18 2:00s 1:00 S
Rule Austria 1980 only - Apr 6 0:00 1:00 S
Rule Austria 1980 only - Sep 28 0:00 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Vienna 1:05:21 - LMT 1893 Apr
1:00 C-Eur CE%sT 1920
1:00 Austria CE%sT 1940 Apr 1 2:00s
1:00 C-Eur CE%sT 1945 Apr 2 2:00s
1:00 1:00 CEST 1945 Apr 12 2:00s
1:00 - CET 1946
1:00 Austria CE%sT 1981
1:00 EU CE%sT
# Belarus
#
# From Stepan Golosunov (2016-07-02):
# http://www.lawbelarus.com/repub/sub30/texf9611.htm
# (Act of the Cabinet of Ministers of the Republic of Belarus from
# 1992-03-25 No. 157) ... says clocks were to be moved forward at 2:00
# on last Sunday of March and backward at 3:00 on last Sunday of September
# (the same as previous USSR and contemporary Russian regulations).
#
# From Yauhen Kharuzhy (2011-09-16):
# By latest Belarus government act Europe/Minsk timezone was changed to
# GMT+3 without DST (was GMT+2 with DST).
#
# Sources (Russian language):
# http://www.belta.by/ru/all_news/society/V-Belarusi-otmenjaetsja-perexod-na-sezonnoe-vremja_i_572952.html
# http://naviny.by/rubrics/society/2011/09/16/ic_articles_116_175144/
# https://news.tut.by/society/250578.html
#
# From Alexander Bokovoy (2014-10-09):
# Belarussian government decided against changing to winter time....
# http://eng.belta.by/all_news/society/Belarus-decides-against-adjusting-time-in-Russias-wake_i_76335.html
#
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Minsk 1:50:16 - LMT 1880
1:50 - MMT 1924 May 2 # Minsk Mean Time
2:00 - EET 1930 Jun 21
3:00 - MSK 1941 Jun 28
1:00 C-Eur CE%sT 1944 Jul 3
3:00 Russia MSK/MSD 1990
3:00 - MSK 1991 Mar 31 2:00s
2:00 Russia EE%sT 2011 Mar 27 2:00s
3:00 - +03
# Belgium
#
-# From Paul Eggert (1997-07-02):
+# From Michael Deckers (2019-08-25):
+# The exposition in the web page
+# https://www.bestor.be/wiki/index.php/Voyager_dans_le_temps._L%E2%80%99introduction_de_la_norme_de_Greenwich_en_Belgique
+# gives several contemporary sources from which one can conclude that
+# the switch in Europe/Brussels on 1892-05-01 was from 00:17:30 to 00:00:00.
+#
+# From Paul Eggert (2019-08-28):
+# This quote helps explain the late-1914 situation:
+# In early November 1914, the Germans imposed the time zone used in central
+# Europe and forced the inhabitants to set their watches and public clocks
+# sixty minutes ahead. Many were reluctant to accept "German time" and
+# continued to use "Belgian time" among themselves. Reflecting the spirit of
+# resistance that arose in the population, a song made fun of this change....
+# The song ended:
+# Putting your clock forward
+# Will but hasten the happy hour
+# When we kick out the Boches!
+# See: Pluvinage G. Brussels on German time. Cahiers Bruxellois -
+# Brusselse Cahiers. 2014;XLVI(1E):15-38.
+# https://www.cairn.info/revue-cahiers-bruxellois-2014-1E-page-15.htm
+#
+# Entries from 1914 through 1917 are taken from "De tijd in België"
+# <https://www.astro.oma.be/GENERAL/INFO/nli001a.html>.
# Entries from 1918 through 1991 are taken from:
# Annuaire de L'Observatoire Royal de Belgique,
# Avenue Circulaire, 3, B-1180 BRUXELLES, CLVIIe année, 1991
# (Imprimerie HAYEZ, s.p.r.l., Rue Fin, 4, 1080 BRUXELLES, MCMXC),
# pp 8-9.
-# LMT before 1892 was 0:17:30, according to the official journal of Belgium:
-# Moniteur Belge, Samedi 30 Avril 1892, N.121.
-# Thanks to Pascal Delmoitie for these references.
+# Thanks to Pascal Delmoitie for the 1918/1991 references.
# The 1918 rules are listed for completeness; they apply to unoccupied Belgium.
# Assume Brussels switched to WET in 1918 when the armistice took effect.
#
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Belgium 1918 only - Mar 9 0:00s 1:00 S
Rule Belgium 1918 1919 - Oct Sat>=1 23:00s 0 -
Rule Belgium 1919 only - Mar 1 23:00s 1:00 S
Rule Belgium 1920 only - Feb 14 23:00s 1:00 S
Rule Belgium 1920 only - Oct 23 23:00s 0 -
Rule Belgium 1921 only - Mar 14 23:00s 1:00 S
Rule Belgium 1921 only - Oct 25 23:00s 0 -
Rule Belgium 1922 only - Mar 25 23:00s 1:00 S
Rule Belgium 1922 1927 - Oct Sat>=1 23:00s 0 -
Rule Belgium 1923 only - Apr 21 23:00s 1:00 S
Rule Belgium 1924 only - Mar 29 23:00s 1:00 S
Rule Belgium 1925 only - Apr 4 23:00s 1:00 S
# DSH writes that a royal decree of 1926-02-22 specified the Sun following 3rd
# Sat in Apr (except if it's Easter, in which case it's one Sunday earlier),
# to Sun following 1st Sat in Oct, and that a royal decree of 1928-09-15
# changed the transition times to 02:00 GMT.
Rule Belgium 1926 only - Apr 17 23:00s 1:00 S
Rule Belgium 1927 only - Apr 9 23:00s 1:00 S
Rule Belgium 1928 only - Apr 14 23:00s 1:00 S
Rule Belgium 1928 1938 - Oct Sun>=2 2:00s 0 -
Rule Belgium 1929 only - Apr 21 2:00s 1:00 S
Rule Belgium 1930 only - Apr 13 2:00s 1:00 S
Rule Belgium 1931 only - Apr 19 2:00s 1:00 S
Rule Belgium 1932 only - Apr 3 2:00s 1:00 S
Rule Belgium 1933 only - Mar 26 2:00s 1:00 S
Rule Belgium 1934 only - Apr 8 2:00s 1:00 S
Rule Belgium 1935 only - Mar 31 2:00s 1:00 S
Rule Belgium 1936 only - Apr 19 2:00s 1:00 S
Rule Belgium 1937 only - Apr 4 2:00s 1:00 S
Rule Belgium 1938 only - Mar 27 2:00s 1:00 S
Rule Belgium 1939 only - Apr 16 2:00s 1:00 S
Rule Belgium 1939 only - Nov 19 2:00s 0 -
Rule Belgium 1940 only - Feb 25 2:00s 1:00 S
Rule Belgium 1944 only - Sep 17 2:00s 0 -
Rule Belgium 1945 only - Apr 2 2:00s 1:00 S
Rule Belgium 1945 only - Sep 16 2:00s 0 -
Rule Belgium 1946 only - May 19 2:00s 1:00 S
Rule Belgium 1946 only - Oct 7 2:00s 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Brussels 0:17:30 - LMT 1880
- 0:17:30 - BMT 1892 May 1 12:00 # Brussels MT
+ 0:17:30 - BMT 1892 May 1 00:17:30
0:00 - WET 1914 Nov 8
1:00 - CET 1916 May 1 0:00
1:00 C-Eur CE%sT 1918 Nov 11 11:00u
0:00 Belgium WE%sT 1940 May 20 2:00s
1:00 C-Eur CE%sT 1944 Sep 3
1:00 Belgium CE%sT 1977
1:00 EU CE%sT
# Bosnia and Herzegovina
# See Europe/Belgrade.
# Bulgaria
#
# From Plamen Simenov via Steffen Thorsen (1999-09-09):
# A document of Government of Bulgaria (No. 94/1997) says:
# EET -> EETDST is in 03:00 Local time in last Sunday of March ...
# EETDST -> EET is in 04:00 Local time in last Sunday of October
#
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Bulg 1979 only - Mar 31 23:00 1:00 S
Rule Bulg 1979 only - Oct 1 1:00 0 -
Rule Bulg 1980 1982 - Apr Sat>=1 23:00 1:00 S
Rule Bulg 1980 only - Sep 29 1:00 0 -
Rule Bulg 1981 only - Sep 27 2:00 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Sofia 1:33:16 - LMT 1880
1:56:56 - IMT 1894 Nov 30 # Istanbul MT?
2:00 - EET 1942 Nov 2 3:00
1:00 C-Eur CE%sT 1945
1:00 - CET 1945 Apr 2 3:00
2:00 - EET 1979 Mar 31 23:00
2:00 Bulg EE%sT 1982 Sep 26 3:00
2:00 C-Eur EE%sT 1991
2:00 E-Eur EE%sT 1997
2:00 EU EE%sT
# Croatia
# See Europe/Belgrade.
# Cyprus
# Please see the 'asia' file for Asia/Nicosia.
# Czech Republic / Czechia
#
# From Paul Eggert (2018-04-15):
# The source for Czech data is: Kdy začíná a končí letní čas. 2018-04-15.
# https://kalendar.beda.cz/kdy-zacina-a-konci-letni-cas
# We know of no English-language name for historical Czech winter time;
# abbreviate it as "GMT", as it happened to be GMT.
#
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Czech 1945 only - Apr Mon>=1 2:00s 1:00 S
Rule Czech 1945 only - Oct 1 2:00s 0 -
Rule Czech 1946 only - May 6 2:00s 1:00 S
Rule Czech 1946 1949 - Oct Sun>=1 2:00s 0 -
Rule Czech 1947 1948 - Apr Sun>=15 2:00s 1:00 S
Rule Czech 1949 only - Apr 9 2:00s 1:00 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Prague 0:57:44 - LMT 1850
0:57:44 - PMT 1891 Oct # Prague Mean Time
1:00 C-Eur CE%sT 1945 May 9
1:00 Czech CE%sT 1946 Dec 1 3:00
# Vanguard section, for zic and other parsers that support negative DST.
1:00 -1:00 GMT 1947 Feb 23 2:00
# Rearguard section, for parsers that do not support negative DST.
# 0:00 - GMT 1947 Feb 23 2:00
# End of rearguard section.
1:00 Czech CE%sT 1979
1:00 EU CE%sT
# Use Europe/Prague also for Slovakia.
# Denmark, Faroe Islands, and Greenland
# From Jesper Nørgaard Welen (2005-04-26):
# http://www.hum.aau.dk/~poe/tid/tine/DanskTid.htm says that the law
# [introducing standard time] was in effect from 1894-01-01....
# The page http://www.retsinfo.dk/_GETDOCI_/ACCN/A18930008330-REGL
# confirms this, and states that the law was put forth 1893-03-29.
#
# The EU [actually, EEC and Euratom] treaty with effect from 1973:
# http://www.retsinfo.dk/_GETDOCI_/ACCN/A19722110030-REGL
#
# This provoked a new law from 1974 to make possible summer time changes
# in subsequent decrees with the law
# http://www.retsinfo.dk/_GETDOCI_/ACCN/A19740022330-REGL
#
# It seems however that no decree was set forward until 1980. I have
# not found any decree, but in another related law, the effecting DST
# changes are stated explicitly to be from 1980-04-06 at 02:00 to
# 1980-09-28 at 02:00. If this is true, this differs slightly from
# the EU rule in that DST runs to 02:00, not 03:00. We don't know
# when Denmark began using the EU rule correctly, but we have only
# confirmation of the 1980-time, so I presume it was correct in 1981:
# The law is about the management of the extra hour, concerning
# working hours reported and effect on obligatory-rest rules (which
# was suspended on that night):
# http://www.retsinfo.dk/_GETDOCI_/ACCN/C19801120554-REGL
# From Jesper Nørgaard Welen (2005-06-11):
# The Herning Folkeblad (1980-09-26) reported that the night between
# Saturday and Sunday the clock is set back from three to two.
# From Paul Eggert (2005-06-11):
# Hence the "02:00" of the 1980 law refers to standard time, not
# wall-clock time, and so the EU rules were in effect in 1980.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Denmark 1916 only - May 14 23:00 1:00 S
Rule Denmark 1916 only - Sep 30 23:00 0 -
Rule Denmark 1940 only - May 15 0:00 1:00 S
Rule Denmark 1945 only - Apr 2 2:00s 1:00 S
Rule Denmark 1945 only - Aug 15 2:00s 0 -
Rule Denmark 1946 only - May 1 2:00s 1:00 S
Rule Denmark 1946 only - Sep 1 2:00s 0 -
Rule Denmark 1947 only - May 4 2:00s 1:00 S
Rule Denmark 1947 only - Aug 10 2:00s 0 -
Rule Denmark 1948 only - May 9 2:00s 1:00 S
Rule Denmark 1948 only - Aug 8 2:00s 0 -
#
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Copenhagen 0:50:20 - LMT 1890
0:50:20 - CMT 1894 Jan 1 # Copenhagen MT
1:00 Denmark CE%sT 1942 Nov 2 2:00s
1:00 C-Eur CE%sT 1945 Apr 2 2:00
1:00 Denmark CE%sT 1980
1:00 EU CE%sT
Zone Atlantic/Faroe -0:27:04 - LMT 1908 Jan 11 # Tórshavn
0:00 - WET 1981
0:00 EU WE%sT
#
# From Paul Eggert (2004-10-31):
# During World War II, Germany maintained secret manned weather stations in
# East Greenland and Franz Josef Land, but we don't know their time zones.
# My source for this is Wilhelm Dege's book mentioned under Svalbard.
#
# From Paul Eggert (2017-12-10):
# Greenland joined the European Communities as part of Denmark,
# obtained home rule on 1979-05-01, and left the European Communities
# on 1985-02-01. It therefore should have been using EU
# rules at least through 1984. Shanks & Pottenger say Scoresbysund and Godthåb
# used C-Eur rules after 1980, but IATA SSIM (1991/1996) says they use EU
# rules since at least 1991. Assume EU rules since 1980.
# From Gwillim Law (2001-06-06), citing
# <http://www.statkart.no/efs/efshefter/2001/efs5-2001.pdf> (2001-03-15),
# and with translations corrected by Steffen Thorsen:
#
# Greenland has four local times, and the relation to UTC
# is according to the following time line:
#
# The military zone near Thule UTC-4
# Standard Greenland time UTC-3
# Scoresbysund UTC-1
# Danmarkshavn UTC
#
# In the military area near Thule and in Danmarkshavn DST will not be
# introduced.
# From Rives McDow (2001-11-01):
#
# I correspond regularly with the Dansk Polarcenter, and wrote them at
# the time to clarify the situation in Thule. Unfortunately, I have
# not heard back from them regarding my recent letter. [But I have
# info from earlier correspondence.]
#
# According to the center, a very small local time zone around Thule
# Air Base keeps the time according to UTC-4, implementing daylight
# savings using North America rules, changing the time at 02:00 local time....
#
# The east coast of Greenland north of the community of Scoresbysund
# uses UTC in the same way as in Iceland, year round, with no dst.
# There are just a few stations on this coast, including the
# Danmarkshavn ICAO weather station mentioned in your September 29th
# email. The other stations are two sledge patrol stations in
# Mestersvig and Daneborg, the air force base at Station Nord, and the
# DPC research station at Zackenberg.
#
# Scoresbysund and two small villages nearby keep time UTC-1 and use
# the same daylight savings time period as in West Greenland (Godthåb).
#
# The rest of Greenland, including Godthåb (this area, although it
# includes central Greenland, is known as west Greenland), keeps time
# UTC-3, with daylight savings methods according to European rules.
#
# It is common procedure to use UTC 0 in the wilderness of East and
# North Greenland, because it is mainly Icelandic aircraft operators
# maintaining traffic in these areas. However, the official status of
# this area is that it sticks with Godthåb time. This area might be
# considered a dual time zone in some respects because of this.
# From Rives McDow (2001-11-19):
# I heard back from someone stationed at Thule; the time change took place
# there at 2:00 AM.
# From Paul Eggert (2006-03-22):
# From 1997 on the CIA map shows Danmarkshavn on GMT;
# the 1995 map as like Godthåb.
# For lack of better info, assume they were like Godthåb before 1996.
# startkart.no says Thule does not observe DST, but this is clearly an error,
# so go with Shanks & Pottenger for Thule transitions until this year.
# For 2007 on assume Thule will stay in sync with US DST rules.
# From J William Piggott (2016-02-20):
# "Greenland north of the community of Scoresbysund" is officially named
# "National Park" by Executive Order:
# http://naalakkersuisut.gl/~/media/Nanoq/Files/Attached%20Files/Engelske-tekster/Legislation/Executive%20Order%20National%20Park.rtf
# It is their only National Park.
#
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Thule 1991 1992 - Mar lastSun 2:00 1:00 D
Rule Thule 1991 1992 - Sep lastSun 2:00 0 S
Rule Thule 1993 2006 - Apr Sun>=1 2:00 1:00 D
Rule Thule 1993 2006 - Oct lastSun 2:00 0 S
Rule Thule 2007 max - Mar Sun>=8 2:00 1:00 D
Rule Thule 2007 max - Nov Sun>=1 2:00 0 S
#
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Danmarkshavn -1:14:40 - LMT 1916 Jul 28
-3:00 - -03 1980 Apr 6 2:00
-3:00 EU -03/-02 1996
0:00 - GMT
Zone America/Scoresbysund -1:27:52 - LMT 1916 Jul 28 # Ittoqqortoormiit
-2:00 - -02 1980 Apr 6 2:00
-2:00 C-Eur -02/-01 1981 Mar 29
-1:00 EU -01/+00
Zone America/Godthab -3:26:56 - LMT 1916 Jul 28 # Nuuk
-3:00 - -03 1980 Apr 6 2:00
-3:00 EU -03/-02
Zone America/Thule -4:35:08 - LMT 1916 Jul 28 # Pituffik air base
-4:00 Thule A%sT
# Estonia
#
# From Paul Eggert (2016-03-18):
# The 1989 transition is from USSR act No. 227 (1989-03-14).
#
# From Peter Ilieve (1994-10-15):
# A relative in Tallinn confirms the accuracy of the data for 1989 onwards
# [through 1994] and gives the legal authority for it,
# a regulation of the Government of Estonia, No. 111 of 1989....
#
# From Peter Ilieve (1996-10-28):
# [IATA SSIM (1992/1996) claims that the Baltic republics switch at 01:00s,
# but a relative confirms that Estonia still switches at 02:00s, writing:]
# "I do not [know] exactly but there are some little different
# (confusing) rules for International Air and Railway Transport Schedules
# conversion in Sunday connected with end of summer time in Estonia....
# A discussion is running about the summer time efficiency and effect on
# human physiology. It seems that Estonia maybe will not change to
# summer time next spring."
# From Peter Ilieve (1998-11-04), heavily edited:
# The 1998-09-22 Estonian time law
# http://trip.rk.ee/cgi-bin/thw?${BASE}=akt&${OOHTML}=rtd&TA=1998&TO=1&AN=1390
# refers to the Eighth Directive and cites the association agreement between
# the EU and Estonia, ratified by the Estonian law (RT II 1995, 22-27, 120).
#
# I also asked [my relative] whether they use any standard abbreviation
# for their standard and summer times. He says no, they use "suveaeg"
# (summer time) and "talveaeg" (winter time).
# From The Baltic Times <https://www.baltictimes.com/> (1999-09-09)
# via Steffen Thorsen:
# This year will mark the last time Estonia shifts to summer time,
# a council of the ruling coalition announced Sept. 6....
# But what this could mean for Estonia's chances of joining the European
# Union are still unclear. In 1994, the EU declared summer time compulsory
# for all member states until 2001. Brussels has yet to decide what to do
# after that.
# From Mart Oruaas (2000-01-29):
# Regulation No. 301 (1999-10-12) obsoletes previous regulation
# No. 206 (1998-09-22) and thus sticks Estonia to +02:00 GMT for all
# the year round. The regulation is effective 1999-11-01.
# From Toomas Soome (2002-02-21):
# The Estonian government has changed once again timezone politics.
# Now we are using again EU rules.
#
# From Urmet Jänes (2002-03-28):
# The legislative reference is Government decree No. 84 on 2002-02-21.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Tallinn 1:39:00 - LMT 1880
1:39:00 - TMT 1918 Feb # Tallinn Mean Time
1:00 C-Eur CE%sT 1919 Jul
1:39:00 - TMT 1921 May
2:00 - EET 1940 Aug 6
3:00 - MSK 1941 Sep 15
1:00 C-Eur CE%sT 1944 Sep 22
3:00 Russia MSK/MSD 1989 Mar 26 2:00s
2:00 1:00 EEST 1989 Sep 24 2:00s
2:00 C-Eur EE%sT 1998 Sep 22
2:00 EU EE%sT 1999 Oct 31 4:00
2:00 - EET 2002 Feb 21
2:00 EU EE%sT
# Finland
# From Hannu Strang (1994-09-25 06:03:37 UTC):
# Well, here in Helsinki we're just changing from summer time to regular one,
# and it's supposed to change at 4am...
# From Janne Snabb (2010-07-15):
#
# I noticed that the Finland data is not accurate for years 1981 and 1982.
# During these two first trial years the DST adjustment was made one hour
# earlier than in forthcoming years. Starting 1983 the adjustment was made
# according to the central European standards.
#
# This is documented in Heikki Oja: Aikakirja 2007, published by The Almanac
# Office of University of Helsinki, ISBN 952-10-3221-9, available online (in
# Finnish) at
# https://almanakka.helsinki.fi/aikakirja/Aikakirja2007kokonaan.pdf
#
# Page 105 (56 in PDF version) has a handy table of all past daylight savings
# transitions. It is easy enough to interpret without Finnish skills.
#
# This is also confirmed by Finnish Broadcasting Company's archive at:
# http://www.yle.fi/elavaarkisto/?s=s&g=1&ag=5&t=&a=3401
#
# The news clip from 1981 says that "the time between 2 and 3 o'clock does not
# exist tonight."
# From Konstantin Hyppönen (2014-06-13):
# [Heikki Oja's book Aikakirja 2013]
# https://almanakka.helsinki.fi/images/aikakirja/Aikakirja2013kokonaan.pdf
# pages 104-105, including a scan from a newspaper published on Apr 2 1942
# say that ... [o]n Apr 2 1942, 24 o'clock (which means Apr 3 1942,
# 00:00), clocks were moved one hour forward. The newspaper
# mentions "on the night from Thursday to Friday"....
# On Oct 4 1942, clocks were moved at 1:00 one hour backwards.
#
# From Paul Eggert (2014-06-14):
# Go with Oja over Shanks.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Finland 1942 only - Apr 2 24:00 1:00 S
Rule Finland 1942 only - Oct 4 1:00 0 -
Rule Finland 1981 1982 - Mar lastSun 2:00 1:00 S
Rule Finland 1981 1982 - Sep lastSun 3:00 0 -
# Milne says Helsinki (Helsingfors) time was 1:39:49.2 (official document);
# round to nearest.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Helsinki 1:39:49 - LMT 1878 May 31
1:39:49 - HMT 1921 May # Helsinki Mean Time
2:00 Finland EE%sT 1983
2:00 EU EE%sT
# Åland Is
Link Europe/Helsinki Europe/Mariehamn
# France
# From Ciro Discepolo (2000-12-20):
#
# Henri Le Corre, Régimes horaires pour le monde entier, Éditions
# Traditionnelles - Paris 2 books, 1993
#
# Gabriel, Traité de l'heure dans le monde, Guy Trédaniel,
# Paris, 1991
#
# Françoise Gauquelin, Problèmes de l'heure résolus en astrologie,
# Guy Trédaniel, Paris 1987
#
# Shank & Pottenger seem to use '24:00' ambiguously; resolve it with Whitman.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule France 1916 only - Jun 14 23:00s 1:00 S
Rule France 1916 1919 - Oct Sun>=1 23:00s 0 -
Rule France 1917 only - Mar 24 23:00s 1:00 S
Rule France 1918 only - Mar 9 23:00s 1:00 S
Rule France 1919 only - Mar 1 23:00s 1:00 S
Rule France 1920 only - Feb 14 23:00s 1:00 S
Rule France 1920 only - Oct 23 23:00s 0 -
Rule France 1921 only - Mar 14 23:00s 1:00 S
Rule France 1921 only - Oct 25 23:00s 0 -
Rule France 1922 only - Mar 25 23:00s 1:00 S
# DSH writes that a law of 1923-05-24 specified 3rd Sat in Apr at 23:00 to 1st
# Sat in Oct at 24:00; and that in 1930, because of Easter, the transitions
# were Apr 12 and Oct 5. Go with Shanks & Pottenger.
Rule France 1922 1938 - Oct Sat>=1 23:00s 0 -
Rule France 1923 only - May 26 23:00s 1:00 S
Rule France 1924 only - Mar 29 23:00s 1:00 S
Rule France 1925 only - Apr 4 23:00s 1:00 S
Rule France 1926 only - Apr 17 23:00s 1:00 S
Rule France 1927 only - Apr 9 23:00s 1:00 S
Rule France 1928 only - Apr 14 23:00s 1:00 S
Rule France 1929 only - Apr 20 23:00s 1:00 S
Rule France 1930 only - Apr 12 23:00s 1:00 S
Rule France 1931 only - Apr 18 23:00s 1:00 S
Rule France 1932 only - Apr 2 23:00s 1:00 S
Rule France 1933 only - Mar 25 23:00s 1:00 S
Rule France 1934 only - Apr 7 23:00s 1:00 S
Rule France 1935 only - Mar 30 23:00s 1:00 S
Rule France 1936 only - Apr 18 23:00s 1:00 S
Rule France 1937 only - Apr 3 23:00s 1:00 S
Rule France 1938 only - Mar 26 23:00s 1:00 S
Rule France 1939 only - Apr 15 23:00s 1:00 S
Rule France 1939 only - Nov 18 23:00s 0 -
Rule France 1940 only - Feb 25 2:00 1:00 S
# The French rules for 1941-1944 were not used in Paris, but Shanks & Pottenger
# write that they were used in Monaco and in many French locations.
# Le Corre writes that the upper limit of the free zone was Arnéguy, Orthez,
# Mont-de-Marsan, Bazas, Langon, Lamothe-Montravel, Marœuil, La
# Rochefoucauld, Champagne-Mouton, La Roche-Posay, La Haye-Descartes,
# Loches, Montrichard, Vierzon, Bourges, Moulins, Digoin,
# Paray-le-Monial, Montceau-les-Mines, Chalon-sur-Saône, Arbois,
# Dole, Morez, St-Claude, and Collonges (Haute-Savoie).
Rule France 1941 only - May 5 0:00 2:00 M # Midsummer
# Shanks & Pottenger say this transition occurred at Oct 6 1:00,
# but go with Denis Excoffier (1997-12-12),
# who quotes the Ephémérides astronomiques for 1998 from Bureau des Longitudes
# as saying 5/10/41 22hUT.
Rule France 1941 only - Oct 6 0:00 1:00 S
Rule France 1942 only - Mar 9 0:00 2:00 M
Rule France 1942 only - Nov 2 3:00 1:00 S
Rule France 1943 only - Mar 29 2:00 2:00 M
Rule France 1943 only - Oct 4 3:00 1:00 S
Rule France 1944 only - Apr 3 2:00 2:00 M
Rule France 1944 only - Oct 8 1:00 1:00 S
Rule France 1945 only - Apr 2 2:00 2:00 M
Rule France 1945 only - Sep 16 3:00 0 -
# Shanks & Pottenger give Mar 28 2:00 and Sep 26 3:00;
# go with Excoffier's 28/3/76 0hUT and 25/9/76 23hUT.
Rule France 1976 only - Mar 28 1:00 1:00 S
Rule France 1976 only - Sep 26 1:00 0 -
# Shanks & Pottenger give 0:09:20 for Paris Mean Time, and Whitman 0:09:05,
# but Howse quotes the actual French legislation as saying 0:09:21.
# Go with Howse. Howse writes that the time in France was officially based
# on PMT-0:09:21 until 1978-08-09, when the time base finally switched to UTC.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Paris 0:09:21 - LMT 1891 Mar 15 0:01
0:09:21 - PMT 1911 Mar 11 0:01 # Paris MT
# Shanks & Pottenger give 1940 Jun 14 0:00; go with Excoffier and Le Corre.
0:00 France WE%sT 1940 Jun 14 23:00
# Le Corre says Paris stuck with occupied-France time after the liberation;
# go with Shanks & Pottenger.
1:00 C-Eur CE%sT 1944 Aug 25
0:00 France WE%sT 1945 Sep 16 3:00
1:00 France CE%sT 1977
1:00 EU CE%sT
# Germany
# From Markus Kuhn (1998-09-29):
# The German time zone web site by the Physikalisch-Technische
# Bundesanstalt contains DST information back to 1916.
# [See tz-link.html for the URL.]
# From Jörg Schilling (2002-10-23):
# In 1945, Berlin was switched to Moscow Summer time (GMT+4) by
# https://www.dhm.de/lemo/html/biografien/BersarinNikolai/
# General [Nikolai] Bersarin.
# From Paul Eggert (2003-03-08):
# http://www.parlament-berlin.de/pds-fraktion.nsf/727459127c8b66ee8525662300459099/defc77cb784f180ac1256c2b0030274b/$FILE/bersarint.pdf
# says that Bersarin issued an order to use Moscow time on May 20.
# However, Moscow did not observe daylight saving in 1945, so
# this was equivalent to UT +03, not +04.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Germany 1946 only - Apr 14 2:00s 1:00 S
Rule Germany 1946 only - Oct 7 2:00s 0 -
Rule Germany 1947 1949 - Oct Sun>=1 2:00s 0 -
# http://www.ptb.de/de/org/4/44/441/salt.htm says the following transition
# occurred at 3:00 MEZ, not the 2:00 MEZ given in Shanks & Pottenger.
# Go with the PTB.
Rule Germany 1947 only - Apr 6 3:00s 1:00 S
Rule Germany 1947 only - May 11 2:00s 2:00 M
Rule Germany 1947 only - Jun 29 3:00 1:00 S
Rule Germany 1948 only - Apr 18 2:00s 1:00 S
Rule Germany 1949 only - Apr 10 2:00s 1:00 S
Rule SovietZone 1945 only - May 24 2:00 2:00 M # Midsummer
Rule SovietZone 1945 only - Sep 24 3:00 1:00 S
Rule SovietZone 1945 only - Nov 18 2:00s 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Berlin 0:53:28 - LMT 1893 Apr
1:00 C-Eur CE%sT 1945 May 24 2:00
1:00 SovietZone CE%sT 1946
1:00 Germany CE%sT 1980
1:00 EU CE%sT
# From Tobias Conradi (2011-09-12):
# Büsingen <http://www.buesingen.de>, surrounded by the Swiss canton
# Schaffhausen, did not start observing DST in 1980 as the rest of DE
# (West Germany at that time) and DD (East Germany at that time) did.
# DD merged into DE, the area is currently covered by code DE in ISO 3166-1,
# which in turn is covered by the zone Europe/Berlin.
#
# Source for the time in Büsingen 1980:
# http://www.srf.ch/player/video?id=c012c029-03b7-4c2b-9164-aa5902cd58d3
# From Arthur David Olson (2012-03-03):
# Büsingen and Zurich have shared clocks since 1970.
Link Europe/Zurich Europe/Busingen
# Georgia
# Please see the "asia" file for Asia/Tbilisi.
# Herodotus (Histories, IV.45) says Georgia north of the Phasis (now Rioni)
# is in Europe. Our reference location Tbilisi is in the Asian part.
# Gibraltar
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Gibraltar -0:21:24 - LMT 1880 Aug 2 0:00s
0:00 GB-Eire %s 1957 Apr 14 2:00
1:00 - CET 1982
1:00 EU CE%sT
# Greece
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
# Whitman gives 1932 Jul 5 - Nov 1; go with Shanks & Pottenger.
Rule Greece 1932 only - Jul 7 0:00 1:00 S
Rule Greece 1932 only - Sep 1 0:00 0 -
# Whitman gives 1941 Apr 25 - ?; go with Shanks & Pottenger.
Rule Greece 1941 only - Apr 7 0:00 1:00 S
# Whitman gives 1942 Feb 2 - ?; go with Shanks & Pottenger.
Rule Greece 1942 only - Nov 2 3:00 0 -
Rule Greece 1943 only - Mar 30 0:00 1:00 S
Rule Greece 1943 only - Oct 4 0:00 0 -
# Whitman gives 1944 Oct 3 - Oct 31; go with Shanks & Pottenger.
Rule Greece 1952 only - Jul 1 0:00 1:00 S
Rule Greece 1952 only - Nov 2 0:00 0 -
Rule Greece 1975 only - Apr 12 0:00s 1:00 S
Rule Greece 1975 only - Nov 26 0:00s 0 -
Rule Greece 1976 only - Apr 11 2:00s 1:00 S
Rule Greece 1976 only - Oct 10 2:00s 0 -
Rule Greece 1977 1978 - Apr Sun>=1 2:00s 1:00 S
Rule Greece 1977 only - Sep 26 2:00s 0 -
Rule Greece 1978 only - Sep 24 4:00 0 -
Rule Greece 1979 only - Apr 1 9:00 1:00 S
Rule Greece 1979 only - Sep 29 2:00 0 -
Rule Greece 1980 only - Apr 1 0:00 1:00 S
Rule Greece 1980 only - Sep 28 0:00 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Athens 1:34:52 - LMT 1895 Sep 14
1:34:52 - AMT 1916 Jul 28 0:01 # Athens MT
2:00 Greece EE%sT 1941 Apr 30
1:00 Greece CE%sT 1944 Apr 4
2:00 Greece EE%sT 1981
# Shanks & Pottenger say it switched to C-Eur in 1981;
# go with EU rules instead, since Greece joined Jan 1.
2:00 EU EE%sT
# Hungary
# From Paul Eggert (2014-07-15):
# Dates for 1916-1945 are taken from:
# Oross A. Jelen a múlt jövője: a nyári időszámítás Magyarországon 1916-1945.
# National Archives of Hungary (2012-10-29).
# http://mnl.gov.hu/a_het_dokumentuma/a_nyari_idoszamitas_magyarorszagon_19161945.html
# This source does not always give times, which are taken from Shanks
# & Pottenger (which disagree about the dates).
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Hungary 1918 only - Apr 1 3:00 1:00 S
Rule Hungary 1918 only - Sep 16 3:00 0 -
Rule Hungary 1919 only - Apr 15 3:00 1:00 S
Rule Hungary 1919 only - Nov 24 3:00 0 -
Rule Hungary 1945 only - May 1 23:00 1:00 S
Rule Hungary 1945 only - Nov 1 0:00 0 -
Rule Hungary 1946 only - Mar 31 2:00s 1:00 S
Rule Hungary 1946 1949 - Oct Sun>=1 2:00s 0 -
Rule Hungary 1947 1949 - Apr Sun>=4 2:00s 1:00 S
Rule Hungary 1950 only - Apr 17 2:00s 1:00 S
Rule Hungary 1950 only - Oct 23 2:00s 0 -
Rule Hungary 1954 1955 - May 23 0:00 1:00 S
Rule Hungary 1954 1955 - Oct 3 0:00 0 -
Rule Hungary 1956 only - Jun Sun>=1 0:00 1:00 S
Rule Hungary 1956 only - Sep lastSun 0:00 0 -
Rule Hungary 1957 only - Jun Sun>=1 1:00 1:00 S
Rule Hungary 1957 only - Sep lastSun 3:00 0 -
Rule Hungary 1980 only - Apr 6 1:00 1:00 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Budapest 1:16:20 - LMT 1890 Oct
1:00 C-Eur CE%sT 1918
1:00 Hungary CE%sT 1941 Apr 8
1:00 C-Eur CE%sT 1945
1:00 Hungary CE%sT 1980 Sep 28 2:00s
1:00 EU CE%sT
# Iceland
#
# From Adam David (1993-11-06):
# The name of the timezone in Iceland for system / mail / news purposes is GMT.
#
# (1993-12-05):
# This material is paraphrased from the 1988 edition of the University of
# Iceland Almanak.
#
# From January 1st, 1908 the whole of Iceland was standardised at 1 hour
# behind GMT. Previously, local mean solar time was used in different parts
# of Iceland, the almanak had been based on Reykjavik mean solar time which
# was 1 hour and 28 minutes behind GMT.
#
# "first day of winter" referred to [below] means the first day of the 26 weeks
# of winter, according to the old icelandic calendar that dates back to the
# time the norsemen first settled Iceland. The first day of winter is always
# Saturday, but is not dependent on the Julian or Gregorian calendars.
#
# (1993-12-10):
# I have a reference from the Oxford Icelandic-English dictionary for the
# beginning of winter, which ties it to the ecclesiastical calendar (and thus
# to the julian/gregorian calendar) over the period in question.
# the winter begins on the Saturday next before St. Luke's day
# (old style), or on St. Luke's day, if a Saturday.
# St. Luke's day ought to be traceable from ecclesiastical sources. "old style"
# might be a reference to the Julian calendar as opposed to Gregorian, or it
# might mean something else (???).
#
# From Paul Eggert (2014-11-22):
# The information below is taken from the 1988 Almanak; see
# http://www.almanak.hi.is/klukkan.html
#
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Iceland 1917 1919 - Feb 19 23:00 1:00 -
Rule Iceland 1917 only - Oct 21 1:00 0 -
Rule Iceland 1918 1919 - Nov 16 1:00 0 -
Rule Iceland 1921 only - Mar 19 23:00 1:00 -
Rule Iceland 1921 only - Jun 23 1:00 0 -
Rule Iceland 1939 only - Apr 29 23:00 1:00 -
Rule Iceland 1939 only - Oct 29 2:00 0 -
Rule Iceland 1940 only - Feb 25 2:00 1:00 -
Rule Iceland 1940 1941 - Nov Sun>=2 1:00s 0 -
Rule Iceland 1941 1942 - Mar Sun>=2 1:00s 1:00 -
# 1943-1946 - first Sunday in March until first Sunday in winter
Rule Iceland 1943 1946 - Mar Sun>=1 1:00s 1:00 -
Rule Iceland 1942 1948 - Oct Sun>=22 1:00s 0 -
# 1947-1967 - first Sunday in April until first Sunday in winter
Rule Iceland 1947 1967 - Apr Sun>=1 1:00s 1:00 -
# 1949 and 1967 Oct transitions delayed by 1 week
Rule Iceland 1949 only - Oct 30 1:00s 0 -
Rule Iceland 1950 1966 - Oct Sun>=22 1:00s 0 -
Rule Iceland 1967 only - Oct 29 1:00s 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Atlantic/Reykjavik -1:28 - LMT 1908
-1:00 Iceland -01/+00 1968 Apr 7 1:00s
0:00 - GMT
# Italy
#
# From Paul Eggert (2001-03-06):
# Sicily and Sardinia each had their own time zones from 1866 to 1893,
# called Palermo Time (+00:53:28) and Cagliari Time (+00:36:32).
# During World War II, German-controlled Italy used German time.
# But these events all occurred before the 1970 cutoff,
# so record only the time in Rome.
#
# From Stephen Trainor (2019-05-06):
# http://www.ac-ilsestante.it/MERIDIANE/ora_legale/ORA_LEGALE_ESTIVA_IN_ITALIA.htm
# ... the [1866] law went into effect on 12 December 1866, rather than
# the date of the decree (22 Sep 1866)
# https://web.archive.org/web/20070824155341/http://www.iav.it/planetario/didastro/didastro/english.htm
# ... "In Italy in 1866 there were 6 railway times (Torino, Verona, Firenze,
# Roma, Napoli, Palermo). On that year it was decided to unify them, adopting
# the average time of Rome (even if this city was not yet part of the
# kingdom). On the 12th December 1866, on the starting of the winter time
# table, it took effect in the railways, the post office and the telegraph,
# not only for the internal service but also for the public.... Milano set
# the public watches on the Rome time on the same day (12th December 1866),
# Torino and Bologna on the 1st January 1867, Venezia the 1st May 1880 and the
# last city was Cagliari in 1886."
#
# From Luigi Rosa (2019-05-07):
# this is the scan of the decree:
# http://www.radiomarconi.com/marconi/filopanti/1866c.jpg
#
# From Michael Deckers (2016-10-24):
# http://www.ac-ilsestante.it/MERIDIANE/ora_legale quotes a law of 1893-08-10
# ... [translated as] "The preceding dispositions will enter into
# force at the instant at which, according to the time specified in
# the 1st article, the 1st of November 1893 will begin...."
#
# From Pierpaolo Bernardi (2016-10-20):
# The authoritative source for time in Italy is the national metrological
# institute, which has a summary page of historical DST data at
# http://www.inrim.it/res/tf/ora_legale_i.shtml
# [now at http://oldsite.inrim.it/res/tf/ora_legale_i.shtml as of 2017]
# (2016-10-24):
# http://www.renzobaldini.it/le-ore-legali-in-italia/
# has still different data for 1944. It divides Italy in two, as
# there were effectively two governments at the time, north of Gothic
# Line German controlled territory, official government RSI, and south
# of the Gothic Line, controlled by allied armies.
#
# From Brian Inglis (2016-10-23):
# Viceregal LEGISLATIVE DECREE. 14 September 1944, no. 219.
# Restoration of Standard Time. (044U0219) (OJ 62 of 30.9.1944) ...
# Given the R. law decreed on 1944-03-29, no. 92, by which standard time is
# advanced to sixty minutes later starting at hour two on 1944-04-02; ...
# Starting at hour three on the date 1944-09-17 standard time will be resumed.
#
+# From Alois Triendl (2019-07-02):
+# I spent 6 Euros to buy two archive copies of Il Messaggero, a Roman paper,
+# for 1 and 2 April 1944. The edition of 2 April has this note: "Tonight at 2
+# am, put forward the clock by one hour. Remember that in the night between
+# today and Monday the 'ora legale' will come in force again." That makes it
+# clear that in Rome the change was on Monday, 3 April 1944 at 2 am.
+#
# From Paul Eggert (2016-10-27):
# Go with INRiM for DST rules, except as corrected by Inglis for 1944
# for the Kingdom of Italy. This is consistent with Renzo Baldini.
# Model Rome's occupation by using C-Eur rules from 1943-09-10
# to 1944-06-04; although Rome was an open city during this period, it
# was effectively controlled by Germany.
#
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Italy 1916 only - Jun 3 24:00 1:00 S
Rule Italy 1916 1917 - Sep 30 24:00 0 -
Rule Italy 1917 only - Mar 31 24:00 1:00 S
Rule Italy 1918 only - Mar 9 24:00 1:00 S
Rule Italy 1918 only - Oct 6 24:00 0 -
Rule Italy 1919 only - Mar 1 24:00 1:00 S
Rule Italy 1919 only - Oct 4 24:00 0 -
Rule Italy 1920 only - Mar 20 24:00 1:00 S
Rule Italy 1920 only - Sep 18 24:00 0 -
Rule Italy 1940 only - Jun 14 24:00 1:00 S
Rule Italy 1942 only - Nov 2 2:00s 0 -
Rule Italy 1943 only - Mar 29 2:00s 1:00 S
Rule Italy 1943 only - Oct 4 2:00s 0 -
Rule Italy 1944 only - Apr 2 2:00s 1:00 S
Rule Italy 1944 only - Sep 17 2:00s 0 -
Rule Italy 1945 only - Apr 2 2:00 1:00 S
Rule Italy 1945 only - Sep 15 1:00 0 -
Rule Italy 1946 only - Mar 17 2:00s 1:00 S
Rule Italy 1946 only - Oct 6 2:00s 0 -
Rule Italy 1947 only - Mar 16 0:00s 1:00 S
Rule Italy 1947 only - Oct 5 0:00s 0 -
Rule Italy 1948 only - Feb 29 2:00s 1:00 S
Rule Italy 1948 only - Oct 3 2:00s 0 -
Rule Italy 1966 1968 - May Sun>=22 0:00s 1:00 S
Rule Italy 1966 only - Sep 24 24:00 0 -
Rule Italy 1967 1969 - Sep Sun>=22 0:00s 0 -
Rule Italy 1969 only - Jun 1 0:00s 1:00 S
Rule Italy 1970 only - May 31 0:00s 1:00 S
Rule Italy 1970 only - Sep lastSun 0:00s 0 -
Rule Italy 1971 1972 - May Sun>=22 0:00s 1:00 S
Rule Italy 1971 only - Sep lastSun 0:00s 0 -
Rule Italy 1972 only - Oct 1 0:00s 0 -
Rule Italy 1973 only - Jun 3 0:00s 1:00 S
Rule Italy 1973 1974 - Sep lastSun 0:00s 0 -
Rule Italy 1974 only - May 26 0:00s 1:00 S
Rule Italy 1975 only - Jun 1 0:00s 1:00 S
Rule Italy 1975 1977 - Sep lastSun 0:00s 0 -
Rule Italy 1976 only - May 30 0:00s 1:00 S
Rule Italy 1977 1979 - May Sun>=22 0:00s 1:00 S
Rule Italy 1978 only - Oct 1 0:00s 0 -
Rule Italy 1979 only - Sep 30 0:00s 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Rome 0:49:56 - LMT 1866 Dec 12
0:49:56 - RMT 1893 Oct 31 23:49:56 # Rome Mean
1:00 Italy CE%sT 1943 Sep 10
1:00 C-Eur CE%sT 1944 Jun 4
1:00 Italy CE%sT 1980
1:00 EU CE%sT
Link Europe/Rome Europe/Vatican
Link Europe/Rome Europe/San_Marino
# Latvia
# From Liene Kanepe (1998-09-17):
# I asked about this matter Scientific Secretary of the Institute of Astronomy
# of The University of Latvia Dr. paed Mr. Ilgonis Vilks. I also searched the
# correct data in juridical acts and I found some juridical documents about
# changes in the counting of time in Latvia from 1981....
#
# Act No. 35 of the Council of Ministers of Latvian SSR of 1981-01-22 ...
# according to the Act No. 925 of the Council of Ministers of USSR of 1980-10-24
# ...: all year round the time of 2nd time zone + 1 hour, in addition turning
# the hands of the clock 1 hour forward on 1 April at 00:00 (GMT 31 March 21:00)
# and 1 hour backward on the 1 October at 00:00 (GMT 30 September 20:00).
#
# Act No. 592 of the Council of Ministers of Latvian SSR of 1984-09-24 ...
# according to the Act No. 967 of the Council of Ministers of USSR of 1984-09-13
# ...: all year round the time of 2nd time zone + 1 hour, in addition turning
# the hands of the clock 1 hour forward on the last Sunday of March at 02:00
# (GMT 23:00 on the previous day) and 1 hour backward on the last Sunday of
# September at 03:00 (GMT 23:00 on the previous day).
#
# Act No. 81 of the Council of Ministers of Latvian SSR of 1989-03-22 ...
# according to the Act No. 227 of the Council of Ministers of USSR of 1989-03-14
# ...: since the last Sunday of March 1989 in Lithuanian SSR, Latvian SSR,
# Estonian SSR and Kaliningrad region of Russian Federation all year round the
# time of 2nd time zone (Moscow time minus one hour). On the territory of Latvia
# transition to summer time is performed on the last Sunday of March at 02:00
# (GMT 00:00), turning the hands of the clock 1 hour forward. The end of
# daylight saving time is performed on the last Sunday of September at 03:00
# (GMT 00:00), turning the hands of the clock 1 hour backward. Exception is
# 1989-03-26, when we must not turn the hands of the clock....
#
# The Regulations of the Cabinet of Ministers of the Republic of Latvia of
# 1997-01-21 on transition to Summer time ... established the same order of
# daylight savings time settings as in the States of the European Union.
# From Andrei Ivanov (2000-03-06):
# This year Latvia will not switch to Daylight Savings Time (as specified in
# The Regulations of the Cabinet of Ministers of the Rep. of Latvia of
# 29-Feb-2000 (No. 79) <http://www.lv-laiks.lv/wwwraksti/2000/071072/vd4.htm>,
# in Latvian for subscribers only).
# From RFE/RL Newsline
# http://www.rferl.org/newsline/2001/01/3-CEE/cee-030101.html
# (2001-01-03), noted after a heads-up by Rives McDow:
# The Latvian government on 2 January decided that the country will
# institute daylight-saving time this spring, LETA reported.
# Last February the three Baltic states decided not to turn back their
# clocks one hour in the spring....
# Minister of Economy Aigars Kalvītis noted that Latvia had too few
# daylight hours and thus decided to comply with a draft European
# Commission directive that provides for instituting daylight-saving
# time in EU countries between 2002 and 2006. The Latvian government
# urged Lithuania and Estonia to adopt a similar time policy, but it
# appears that they will not do so....
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Latvia 1989 1996 - Mar lastSun 2:00s 1:00 S
Rule Latvia 1989 1996 - Sep lastSun 2:00s 0 -
# Milne 1899 says Riga was 1:36:28 (Polytechnique House time).
# Byalokoz 1919 says Latvia was 1:36:34.
# Go with Byalokoz.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Riga 1:36:34 - LMT 1880
1:36:34 - RMT 1918 Apr 15 2:00 # Riga MT
1:36:34 1:00 LST 1918 Sep 16 3:00 # Latvian ST
1:36:34 - RMT 1919 Apr 1 2:00
1:36:34 1:00 LST 1919 May 22 3:00
1:36:34 - RMT 1926 May 11
2:00 - EET 1940 Aug 5
3:00 - MSK 1941 Jul
1:00 C-Eur CE%sT 1944 Oct 13
3:00 Russia MSK/MSD 1989 Mar lastSun 2:00s
2:00 1:00 EEST 1989 Sep lastSun 2:00s
2:00 Latvia EE%sT 1997 Jan 21
2:00 EU EE%sT 2000 Feb 29
2:00 - EET 2001 Jan 2
2:00 EU EE%sT
# Liechtenstein
# From Paul Eggert (2013-09-09):
# Shanks & Pottenger say Vaduz is like Zurich.
-# From Alois Treindl (2013-09-18):
-# http://www.eliechtensteinensia.li/LIJ/1978/1938-1978/1941.pdf
-# ... confirms on p. 6 that Liechtenstein followed Switzerland in 1941 and 1942.
-# I ... translate only the last two paragraphs:
-# ... during second world war, in the years 1941 and 1942, Liechtenstein
-# introduced daylight saving time, adapting to Switzerland. From 1943 on
-# central European time was in force throughout the year.
-# From a report of the duke's government to the high council,
-# regarding the introduction of a time law, of 31 May 1977.
+# From Alois Treindl (2019-07-04):
+# I was able to access the online archive of the Vaduz paper Vaterland ...
+# I could confirm from the paper that Liechtenstein did in fact follow
+# the same DST in 1941 and 1942 as Switzerland did.
Link Europe/Zurich Europe/Vaduz
# Lithuania
# From Paul Eggert (2016-03-18):
# The 1989 transition is from USSR act No. 227 (1989-03-14).
# From Paul Eggert (1996-11-22):
# IATA SSIM (1992/1996) says Lithuania uses W-Eur rules, but since it is
# known to be wrong about Estonia and Latvia, assume it's wrong here too.
# From Marius Gedminas (1998-08-07):
# I would like to inform that in this year Lithuanian time zone
# (Europe/Vilnius) was changed.
# From ELTA No. 972 (2582) (1999-09-29) <http://www.elta.lt/>,
# via Steffen Thorsen:
# Lithuania has shifted back to the second time zone (GMT plus two hours)
# to be valid here starting from October 31,
# as decided by the national government on Wednesday....
# The Lithuanian government also announced plans to consider a
# motion to give up shifting to summer time in spring, as it was
# already done by Estonia.
# From the Fact File, Lithuanian State Department of Tourism
# <http://www.tourism.lt/informa/ff.htm> (2000-03-27):
# Local time is GMT+2 hours ..., no daylight saving.
# From a user via Klaus Marten (2003-02-07):
# As a candidate for membership of the European Union, Lithuania will
# observe Summer Time in 2003, changing its clocks at the times laid
# down in EU Directive 2000/84 of 19.I.01 (i.e. at the same times as its
# neighbour Latvia). The text of the Lithuanian government Order of
# 7.XI.02 to this effect can be found at
# http://www.lrvk.lt/nut/11/n1749.htm
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Vilnius 1:41:16 - LMT 1880
1:24:00 - WMT 1917 # Warsaw Mean Time
1:35:36 - KMT 1919 Oct 10 # Kaunas Mean Time
1:00 - CET 1920 Jul 12
2:00 - EET 1920 Oct 9
1:00 - CET 1940 Aug 3
3:00 - MSK 1941 Jun 24
1:00 C-Eur CE%sT 1944 Aug
3:00 Russia MSK/MSD 1989 Mar 26 2:00s
2:00 Russia EE%sT 1991 Sep 29 2:00s
2:00 C-Eur EE%sT 1998
2:00 - EET 1998 Mar 29 1:00u
1:00 EU CE%sT 1999 Oct 31 1:00u
2:00 - EET 2003 Jan 1
2:00 EU EE%sT
# Luxembourg
# Whitman disagrees with most of these dates in minor ways;
# go with Shanks & Pottenger.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Lux 1916 only - May 14 23:00 1:00 S
Rule Lux 1916 only - Oct 1 1:00 0 -
Rule Lux 1917 only - Apr 28 23:00 1:00 S
Rule Lux 1917 only - Sep 17 1:00 0 -
Rule Lux 1918 only - Apr Mon>=15 2:00s 1:00 S
Rule Lux 1918 only - Sep Mon>=15 2:00s 0 -
Rule Lux 1919 only - Mar 1 23:00 1:00 S
Rule Lux 1919 only - Oct 5 3:00 0 -
Rule Lux 1920 only - Feb 14 23:00 1:00 S
Rule Lux 1920 only - Oct 24 2:00 0 -
Rule Lux 1921 only - Mar 14 23:00 1:00 S
Rule Lux 1921 only - Oct 26 2:00 0 -
Rule Lux 1922 only - Mar 25 23:00 1:00 S
Rule Lux 1922 only - Oct Sun>=2 1:00 0 -
Rule Lux 1923 only - Apr 21 23:00 1:00 S
Rule Lux 1923 only - Oct Sun>=2 2:00 0 -
Rule Lux 1924 only - Mar 29 23:00 1:00 S
Rule Lux 1924 1928 - Oct Sun>=2 1:00 0 -
Rule Lux 1925 only - Apr 5 23:00 1:00 S
Rule Lux 1926 only - Apr 17 23:00 1:00 S
Rule Lux 1927 only - Apr 9 23:00 1:00 S
Rule Lux 1928 only - Apr 14 23:00 1:00 S
Rule Lux 1929 only - Apr 20 23:00 1:00 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Luxembourg 0:24:36 - LMT 1904 Jun
1:00 Lux CE%sT 1918 Nov 25
0:00 Lux WE%sT 1929 Oct 6 2:00s
0:00 Belgium WE%sT 1940 May 14 3:00
1:00 C-Eur WE%sT 1944 Sep 18 3:00
1:00 Belgium CE%sT 1977
1:00 EU CE%sT
# North Macedonia
# See Europe/Belgrade.
# Malta
#
# From Paul Eggert (2016-10-21):
# Assume 1900-1972 was like Rome, overriding Shanks.
#
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Malta 1973 only - Mar 31 0:00s 1:00 S
Rule Malta 1973 only - Sep 29 0:00s 0 -
Rule Malta 1974 only - Apr 21 0:00s 1:00 S
Rule Malta 1974 only - Sep 16 0:00s 0 -
Rule Malta 1975 1979 - Apr Sun>=15 2:00 1:00 S
Rule Malta 1975 1980 - Sep Sun>=15 2:00 0 -
Rule Malta 1980 only - Mar 31 2:00 1:00 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Malta 0:58:04 - LMT 1893 Nov 2 0:00s # Valletta
1:00 Italy CE%sT 1973 Mar 31
1:00 Malta CE%sT 1981
1:00 EU CE%sT
# Moldova
# From Stepan Golosunov (2016-03-07):
# the act of the government of the Republic of Moldova Nr. 132 from 1990-05-04
# http://lex.justice.md/viewdoc.php?action=view&view=doc&id=298782&lang=2
# ... says that since 1990-05-06 on the territory of the Moldavian SSR
# time would be calculated as the standard time of the second time belt
# plus one hour of the "summer" time. To implement that clocks would be
# adjusted one hour backwards at 1990-05-06 2:00. After that "summer"
# time would be cancelled last Sunday of September at 3:00 and
# reintroduced last Sunday of March at 2:00.
# From Paul Eggert (2006-03-22):
# A previous version of this database followed Shanks & Pottenger, who write
# that Tiraspol switched to Moscow time on 1992-01-19 at 02:00.
# However, this is most likely an error, as Moldova declared independence
# on 1991-08-27 (the 1992-01-19 date is that of a Russian decree).
# In early 1992 there was large-scale interethnic violence in the area
# and it's possible that some Russophones continued to observe Moscow time.
# But [two people] separately reported via
# Jesper Nørgaard that as of 2001-01-24 Tiraspol was like Chisinau.
# The Tiraspol entry has therefore been removed for now.
#
# From Alexander Krivenyshev (2011-10-17):
# Pridnestrovian Moldavian Republic (PMR, also known as
# "Pridnestrovie") has abolished seasonal clock change (no transition
# to the Winter Time).
#
# News (in Russian):
# http://www.kyivpost.ua/russia/news/pridnestrove-otkazalos-ot-perehoda-na-zimnee-vremya-30954.html
# http://www.allmoldova.com/moldova-news/1249064116.html
#
# The substance of this change (reinstatement of the Tiraspol entry)
# is from a patch from Petr Machata (2011-10-17)
#
# From Tim Parenti (2011-10-19)
# In addition, being situated at +4651+2938 would give Tiraspol
# a pre-1880 LMT offset of 1:58:32.
#
# (which agrees with the earlier entry that had been removed)
#
# From Alexander Krivenyshev (2011-10-26)
# NO need to divide Moldova into two timezones at this point.
# As of today, Transnistria (Pridnestrovie)- Tiraspol reversed its own
# decision to abolish DST this winter.
# Following Moldova and neighboring Ukraine- Transnistria (Pridnestrovie)-
# Tiraspol will go back to winter time on October 30, 2011.
# News from Moldova (in russian):
# https://ru.publika.md/link_317061.html
# From Roman Tudos (2015-07-02):
# http://lex.justice.md/index.php?action=view&view=doc&lang=1&id=355077
# From Paul Eggert (2015-07-01):
# The abovementioned official link to IGO1445-868/2014 states that
# 2014-10-26's fallback transition occurred at 03:00 local time. Also,
# https://www.trm.md/en/social/la-30-martie-vom-trece-la-ora-de-vara
# says the 2014-03-30 spring-forward transition was at 02:00 local time.
# Guess that since 1997 Moldova has switched one hour before the EU.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Moldova 1997 max - Mar lastSun 2:00 1:00 S
Rule Moldova 1997 max - Oct lastSun 3:00 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Chisinau 1:55:20 - LMT 1880
1:55 - CMT 1918 Feb 15 # Chisinau MT
1:44:24 - BMT 1931 Jul 24 # Bucharest MT
2:00 Romania EE%sT 1940 Aug 15
2:00 1:00 EEST 1941 Jul 17
1:00 C-Eur CE%sT 1944 Aug 24
3:00 Russia MSK/MSD 1990 May 6 2:00
2:00 Russia EE%sT 1992
2:00 E-Eur EE%sT 1997
# See Romania commentary for the guessed 1997 transition to EU rules.
2:00 Moldova EE%sT
# Monaco
# Shanks & Pottenger give 0:09:20 for Paris Mean Time; go with Howse's
# more precise 0:09:21.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Monaco 0:29:32 - LMT 1891 Mar 15
0:09:21 - PMT 1911 Mar 11 # Paris Mean Time
0:00 France WE%sT 1945 Sep 16 3:00
1:00 France CE%sT 1977
1:00 EU CE%sT
# Montenegro
# See Europe/Belgrade.
# Netherlands
# Howse writes that the Netherlands' railways used GMT between 1892 and 1940,
# but for other purposes the Netherlands used Amsterdam mean time.
# However, Robert H. van Gent writes (2001-04-01):
# Howse's statement is only correct up to 1909. From 1909-05-01 (00:00:00
# Amsterdam mean time) onwards, the whole of the Netherlands (including
# the Dutch railways) was required by law to observe Amsterdam mean time
# (19 minutes 32.13 seconds ahead of GMT). This had already been the
# common practice (except for the railways) for many decades but it was
# not until 1909 when the Dutch government finally defined this by law.
# On 1937-07-01 this was changed to 20 minutes (exactly) ahead of GMT and
# was generally known as Dutch Time ("Nederlandse Tijd").
#
# (2001-04-08):
# 1892-05-01 was the date when the Dutch railways were by law required to
# observe GMT while the remainder of the Netherlands adhered to the common
# practice of following Amsterdam mean time.
#
# (2001-04-09):
# In 1835 the authorities of the province of North Holland requested the
# municipal authorities of the towns and cities in the province to observe
# Amsterdam mean time but I do not know in how many cases this request was
# actually followed.
#
# From 1852 onwards the Dutch telegraph offices were by law required to
# observe Amsterdam mean time. As the time signals from the observatory of
# Leiden were also distributed by the telegraph system, I assume that most
# places linked up with the telegraph (and railway) system automatically
# adopted Amsterdam mean time.
#
# Although the early Dutch railway companies initially observed a variety
# of times, most of them had adopted Amsterdam mean time by 1858 but it
# was not until 1866 when they were all required by law to observe
# Amsterdam mean time.
# The data entries before 1945 are taken from
# https://www.staff.science.uu.nl/~gent0113/wettijd/wettijd.htm
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Neth 1916 only - May 1 0:00 1:00 NST # Netherlands Summer Time
Rule Neth 1916 only - Oct 1 0:00 0 AMT # Amsterdam Mean Time
Rule Neth 1917 only - Apr 16 2:00s 1:00 NST
Rule Neth 1917 only - Sep 17 2:00s 0 AMT
Rule Neth 1918 1921 - Apr Mon>=1 2:00s 1:00 NST
Rule Neth 1918 1921 - Sep lastMon 2:00s 0 AMT
Rule Neth 1922 only - Mar lastSun 2:00s 1:00 NST
Rule Neth 1922 1936 - Oct Sun>=2 2:00s 0 AMT
Rule Neth 1923 only - Jun Fri>=1 2:00s 1:00 NST
Rule Neth 1924 only - Mar lastSun 2:00s 1:00 NST
Rule Neth 1925 only - Jun Fri>=1 2:00s 1:00 NST
# From 1926 through 1939 DST began 05-15, except that it was delayed by a week
# in years when 05-15 fell in the Pentecost weekend.
Rule Neth 1926 1931 - May 15 2:00s 1:00 NST
Rule Neth 1932 only - May 22 2:00s 1:00 NST
Rule Neth 1933 1936 - May 15 2:00s 1:00 NST
Rule Neth 1937 only - May 22 2:00s 1:00 NST
Rule Neth 1937 only - Jul 1 0:00 1:00 S
Rule Neth 1937 1939 - Oct Sun>=2 2:00s 0 -
Rule Neth 1938 1939 - May 15 2:00s 1:00 S
Rule Neth 1945 only - Apr 2 2:00s 1:00 S
Rule Neth 1945 only - Sep 16 2:00s 0 -
#
# Amsterdam Mean Time was +00:19:32.13, but the .13 is omitted
# below because the current format requires STDOFF to be an integer.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Amsterdam 0:19:32 - LMT 1835
0:19:32 Neth %s 1937 Jul 1
0:20 Neth +0020/+0120 1940 May 16 0:00
1:00 C-Eur CE%sT 1945 Apr 2 2:00
1:00 Neth CE%sT 1977
1:00 EU CE%sT
# Norway
# http://met.no/met/met_lex/q_u/sommertid.html (2004-01) agrees with Shanks &
# Pottenger.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Norway 1916 only - May 22 1:00 1:00 S
Rule Norway 1916 only - Sep 30 0:00 0 -
Rule Norway 1945 only - Apr 2 2:00s 1:00 S
Rule Norway 1945 only - Oct 1 2:00s 0 -
Rule Norway 1959 1964 - Mar Sun>=15 2:00s 1:00 S
Rule Norway 1959 1965 - Sep Sun>=15 2:00s 0 -
Rule Norway 1965 only - Apr 25 2:00s 1:00 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Oslo 0:43:00 - LMT 1895 Jan 1
1:00 Norway CE%sT 1940 Aug 10 23:00
1:00 C-Eur CE%sT 1945 Apr 2 2:00
1:00 Norway CE%sT 1980
1:00 EU CE%sT
# Svalbard & Jan Mayen
# From Steffen Thorsen (2001-05-01):
# Although I could not find it explicitly, it seems that Jan Mayen and
# Svalbard have been using the same time as Norway at least since the
# time they were declared as parts of Norway. Svalbard was declared
# as a part of Norway by law of 1925-07-17 no 11, section 4 and Jan
# Mayen by law of 1930-02-27 no 2, section 2. (From
# <http://www.lovdata.no/all/nl-19250717-011.html> and
# <http://www.lovdata.no/all/nl-19300227-002.html>). The law/regulation
# for normal/standard time in Norway is from 1894-06-29 no 1 (came
# into operation on 1895-01-01) and Svalbard/Jan Mayen seem to be a
# part of this law since 1925/1930. (From
# <http://www.lovdata.no/all/nl-18940629-001.html>) I have not been
# able to find if Jan Mayen used a different time zone (e.g. -0100)
# before 1930. Jan Mayen has only been "inhabited" since 1921 by
# Norwegian meteorologists and maybe used the same time as Norway ever
# since 1921. Svalbard (Arctic/Longyearbyen) has been inhabited since
# before 1895, and therefore probably changed the local time somewhere
# between 1895 and 1925 (inclusive).
# From Paul Eggert (2013-09-04):
#
# Actually, Jan Mayen was never occupied by Germany during World War II,
# so it must have diverged from Oslo time during the war, as Oslo was
# keeping Berlin time.
#
# <https://www.jan-mayen.no/history.htm> says that the meteorologists
# burned down their station in 1940 and left the island, but returned in
# 1941 with a small Norwegian garrison and continued operations despite
# frequent air attacks from Germans. In 1943 the Americans established a
# radiolocating station on the island, called "Atlantic City". Possibly
# the UT offset changed during the war, but I think it unlikely that
# Jan Mayen used German daylight-saving rules.
#
# Svalbard is more complicated, as it was raided in August 1941 by an
# Allied party that evacuated the civilian population to England (says
# <http://www.bartleby.com/65/sv/Svalbard.html>). The Svalbard FAQ
# <http://www.svalbard.com/SvalbardFAQ.html> says that the Germans were
# expelled on 1942-05-14. However, small parties of Germans did return,
# and according to Wilhelm Dege's book "War North of 80" (1954)
# http://www.ucalgary.ca/UofC/departments/UP/1-55238/1-55238-110-2.html
# the German armed forces at the Svalbard weather station code-named
# Haudegen did not surrender to the Allies until September 1945.
#
# All these events predate our cutoff date of 1970, so use Europe/Oslo
# for these regions.
Link Europe/Oslo Arctic/Longyearbyen
# Poland
# The 1919 dates and times can be found in Tygodnik Urzędowy nr 1 (1919-03-20),
# <http://www.wbc.poznan.pl/publication/32156> pp 1-2.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Poland 1918 1919 - Sep 16 2:00s 0 -
Rule Poland 1919 only - Apr 15 2:00s 1:00 S
Rule Poland 1944 only - Apr 3 2:00s 1:00 S
# Whitman gives 1944 Nov 30; go with Shanks & Pottenger.
Rule Poland 1944 only - Oct 4 2:00 0 -
# For 1944-1948 Whitman gives the previous day; go with Shanks & Pottenger.
Rule Poland 1945 only - Apr 29 0:00 1:00 S
Rule Poland 1945 only - Nov 1 0:00 0 -
# For 1946 on the source is Kazimierz Borkowski,
# Toruń Center for Astronomy, Dept. of Radio Astronomy, Nicolaus Copernicus U.,
# https://www.astro.uni.torun.pl/~kb/Artykuly/U-PA/Czas2.htm#tth_tAb1
# Thanks to Przemysław Augustyniak (2005-05-28) for this reference.
# He also gives these further references:
# Mon Pol nr 13, poz 162 (1995) <http://www.abc.com.pl/serwis/mp/1995/0162.htm>
# Druk nr 2180 (2003) <http://www.senat.gov.pl/k5/dok/sejm/053/2180.pdf>
Rule Poland 1946 only - Apr 14 0:00s 1:00 S
Rule Poland 1946 only - Oct 7 2:00s 0 -
Rule Poland 1947 only - May 4 2:00s 1:00 S
Rule Poland 1947 1949 - Oct Sun>=1 2:00s 0 -
Rule Poland 1948 only - Apr 18 2:00s 1:00 S
Rule Poland 1949 only - Apr 10 2:00s 1:00 S
Rule Poland 1957 only - Jun 2 1:00s 1:00 S
Rule Poland 1957 1958 - Sep lastSun 1:00s 0 -
Rule Poland 1958 only - Mar 30 1:00s 1:00 S
Rule Poland 1959 only - May 31 1:00s 1:00 S
Rule Poland 1959 1961 - Oct Sun>=1 1:00s 0 -
Rule Poland 1960 only - Apr 3 1:00s 1:00 S
Rule Poland 1961 1964 - May lastSun 1:00s 1:00 S
Rule Poland 1962 1964 - Sep lastSun 1:00s 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Warsaw 1:24:00 - LMT 1880
1:24:00 - WMT 1915 Aug 5 # Warsaw Mean Time
1:00 C-Eur CE%sT 1918 Sep 16 3:00
2:00 Poland EE%sT 1922 Jun
1:00 Poland CE%sT 1940 Jun 23 2:00
1:00 C-Eur CE%sT 1944 Oct
1:00 Poland CE%sT 1977
1:00 W-Eur CE%sT 1988
1:00 EU CE%sT
# Portugal
# From Paul Eggert (2014-08-11), after a heads-up from Stephen Colebourne:
# According to a Portuguese decree (1911-05-26)
# https://dre.pt/application/dir/pdf1sdip/1911/05/12500/23132313.pdf
# Lisbon was at -0:36:44.68, but switched to GMT on 1912-01-01 at 00:00.
# Round the old offset to -0:36:45. This agrees with Willett....
#
# From Michael Deckers (2018-02-15):
# article 5 [of the 1911 decree; Deckers's translation] ...:
# These dispositions shall enter into force at the instant at which,
# according to the 2nd article, the civil day January 1, 1912 begins,
# all clocks therefore having to be advanced or set back correspondingly ...
# From Rui Pedro Salgueiro (1992-11-12):
# Portugal has recently (September, 27) changed timezone
# (from WET to MET or CET) to harmonize with EEC.
#
# Martin Bruckmann (1996-02-29) reports via Peter Ilieve
# that Portugal is reverting to 0:00 by not moving its clocks this spring.
# The new Prime Minister was fed up with getting up in the dark in the winter.
#
# From Paul Eggert (1996-11-12):
# IATA SSIM (1991-09) reports several 1991-09 and 1992-09 transitions
# at 02:00u, not 01:00u. Assume that these are typos.
# IATA SSIM (1991/1992) reports that the Azores were at -1:00.
# IATA SSIM (1993-02) says +0:00; later issues (through 1996-09) say -1:00.
# Guess that the Azores changed to EU rules in 1992 (since that's when Portugal
# harmonized with EU rules), and that they stayed +0:00 that winter.
#
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
# DSH writes that despite Decree 1,469 (1915), the change to the clocks was not
# done every year, depending on what Spain did, because of railroad schedules.
# Go with Shanks & Pottenger.
Rule Port 1916 only - Jun 17 23:00 1:00 S
# Whitman gives 1916 Oct 31; go with Shanks & Pottenger.
Rule Port 1916 only - Nov 1 1:00 0 -
Rule Port 1917 only - Feb 28 23:00s 1:00 S
Rule Port 1917 1921 - Oct 14 23:00s 0 -
Rule Port 1918 only - Mar 1 23:00s 1:00 S
Rule Port 1919 only - Feb 28 23:00s 1:00 S
Rule Port 1920 only - Feb 29 23:00s 1:00 S
Rule Port 1921 only - Feb 28 23:00s 1:00 S
Rule Port 1924 only - Apr 16 23:00s 1:00 S
Rule Port 1924 only - Oct 14 23:00s 0 -
Rule Port 1926 only - Apr 17 23:00s 1:00 S
Rule Port 1926 1929 - Oct Sat>=1 23:00s 0 -
Rule Port 1927 only - Apr 9 23:00s 1:00 S
Rule Port 1928 only - Apr 14 23:00s 1:00 S
Rule Port 1929 only - Apr 20 23:00s 1:00 S
Rule Port 1931 only - Apr 18 23:00s 1:00 S
# Whitman gives 1931 Oct 8; go with Shanks & Pottenger.
Rule Port 1931 1932 - Oct Sat>=1 23:00s 0 -
Rule Port 1932 only - Apr 2 23:00s 1:00 S
Rule Port 1934 only - Apr 7 23:00s 1:00 S
# Whitman gives 1934 Oct 5; go with Shanks & Pottenger.
Rule Port 1934 1938 - Oct Sat>=1 23:00s 0 -
# Shanks & Pottenger give 1935 Apr 30; go with Whitman.
Rule Port 1935 only - Mar 30 23:00s 1:00 S
Rule Port 1936 only - Apr 18 23:00s 1:00 S
# Whitman gives 1937 Apr 2; go with Shanks & Pottenger.
Rule Port 1937 only - Apr 3 23:00s 1:00 S
Rule Port 1938 only - Mar 26 23:00s 1:00 S
Rule Port 1939 only - Apr 15 23:00s 1:00 S
# Whitman gives 1939 Oct 7; go with Shanks & Pottenger.
Rule Port 1939 only - Nov 18 23:00s 0 -
Rule Port 1940 only - Feb 24 23:00s 1:00 S
# Shanks & Pottenger give 1940 Oct 7; go with Whitman.
Rule Port 1940 1941 - Oct 5 23:00s 0 -
Rule Port 1941 only - Apr 5 23:00s 1:00 S
Rule Port 1942 1945 - Mar Sat>=8 23:00s 1:00 S
Rule Port 1942 only - Apr 25 22:00s 2:00 M # Midsummer
Rule Port 1942 only - Aug 15 22:00s 1:00 S
Rule Port 1942 1945 - Oct Sat>=24 23:00s 0 -
Rule Port 1943 only - Apr 17 22:00s 2:00 M
Rule Port 1943 1945 - Aug Sat>=25 22:00s 1:00 S
Rule Port 1944 1945 - Apr Sat>=21 22:00s 2:00 M
Rule Port 1946 only - Apr Sat>=1 23:00s 1:00 S
Rule Port 1946 only - Oct Sat>=1 23:00s 0 -
Rule Port 1947 1949 - Apr Sun>=1 2:00s 1:00 S
Rule Port 1947 1949 - Oct Sun>=1 2:00s 0 -
# Shanks & Pottenger say DST was observed in 1950; go with Whitman.
# Whitman gives Oct lastSun for 1952 on; go with Shanks & Pottenger.
Rule Port 1951 1965 - Apr Sun>=1 2:00s 1:00 S
Rule Port 1951 1965 - Oct Sun>=1 2:00s 0 -
Rule Port 1977 only - Mar 27 0:00s 1:00 S
Rule Port 1977 only - Sep 25 0:00s 0 -
Rule Port 1978 1979 - Apr Sun>=1 0:00s 1:00 S
Rule Port 1978 only - Oct 1 0:00s 0 -
Rule Port 1979 1982 - Sep lastSun 1:00s 0 -
Rule Port 1980 only - Mar lastSun 0:00s 1:00 S
Rule Port 1981 1982 - Mar lastSun 1:00s 1:00 S
Rule Port 1983 only - Mar lastSun 2:00s 1:00 S
#
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Lisbon -0:36:45 - LMT 1884
-0:36:45 - LMT 1912 Jan 1 0:00u # Lisbon MT
0:00 Port WE%sT 1966 Apr 3 2:00
1:00 - CET 1976 Sep 26 1:00
0:00 Port WE%sT 1983 Sep 25 1:00s
0:00 W-Eur WE%sT 1992 Sep 27 1:00s
1:00 EU CE%sT 1996 Mar 31 1:00u
0:00 EU WE%sT
# This Zone can be simplified once we assume zic %z.
Zone Atlantic/Azores -1:42:40 - LMT 1884 # Ponta Delgada
-1:54:32 - HMT 1912 Jan 1 2:00u # Horta MT
-2:00 Port -02/-01 1942 Apr 25 22:00s
-2:00 Port +00 1942 Aug 15 22:00s
-2:00 Port -02/-01 1943 Apr 17 22:00s
-2:00 Port +00 1943 Aug 28 22:00s
-2:00 Port -02/-01 1944 Apr 22 22:00s
-2:00 Port +00 1944 Aug 26 22:00s
-2:00 Port -02/-01 1945 Apr 21 22:00s
-2:00 Port +00 1945 Aug 25 22:00s
-2:00 Port -02/-01 1966 Apr 3 2:00
-1:00 Port -01/+00 1983 Sep 25 1:00s
-1:00 W-Eur -01/+00 1992 Sep 27 1:00s
0:00 EU WE%sT 1993 Mar 28 1:00u
-1:00 EU -01/+00
# This Zone can be simplified once we assume zic %z.
Zone Atlantic/Madeira -1:07:36 - LMT 1884 # Funchal
-1:07:36 - FMT 1912 Jan 1 1:00u # Funchal MT
-1:00 Port -01/+00 1942 Apr 25 22:00s
-1:00 Port +01 1942 Aug 15 22:00s
-1:00 Port -01/+00 1943 Apr 17 22:00s
-1:00 Port +01 1943 Aug 28 22:00s
-1:00 Port -01/+00 1944 Apr 22 22:00s
-1:00 Port +01 1944 Aug 26 22:00s
-1:00 Port -01/+00 1945 Apr 21 22:00s
-1:00 Port +01 1945 Aug 25 22:00s
-1:00 Port -01/+00 1966 Apr 3 2:00
0:00 Port WE%sT 1983 Sep 25 1:00s
0:00 EU WE%sT
# Romania
#
# From Paul Eggert (1999-10-07):
# Nine O'clock <http://www.nineoclock.ro/POL/1778pol.html>
# (1998-10-23) reports that the switch occurred at
# 04:00 local time in fall 1998. For lack of better info,
# assume that Romania and Moldova switched to EU rules in 1997,
# the same year as Bulgaria.
#
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Romania 1932 only - May 21 0:00s 1:00 S
Rule Romania 1932 1939 - Oct Sun>=1 0:00s 0 -
Rule Romania 1933 1939 - Apr Sun>=2 0:00s 1:00 S
Rule Romania 1979 only - May 27 0:00 1:00 S
Rule Romania 1979 only - Sep lastSun 0:00 0 -
Rule Romania 1980 only - Apr 5 23:00 1:00 S
Rule Romania 1980 only - Sep lastSun 1:00 0 -
Rule Romania 1991 1993 - Mar lastSun 0:00s 1:00 S
Rule Romania 1991 1993 - Sep lastSun 0:00s 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Bucharest 1:44:24 - LMT 1891 Oct
1:44:24 - BMT 1931 Jul 24 # Bucharest MT
2:00 Romania EE%sT 1981 Mar 29 2:00s
2:00 C-Eur EE%sT 1991
2:00 Romania EE%sT 1994
2:00 E-Eur EE%sT 1997
2:00 EU EE%sT
# Russia
# From Alexander Krivenyshev (2011-09-15):
# Based on last Russian Government Decree No. 725 on August 31, 2011
# (Government document
# http://www.government.ru/gov/results/16355/print/
# in Russian)
# there are few corrections have to be made for some Russian time zones...
# All updated Russian Time Zones were placed in table and translated to English
# by WorldTimeZone.com at the link below:
# http://www.worldtimezone.com/dst_news/dst_news_russia36.htm
# From Sanjeev Gupta (2011-09-27):
# Scans of [Decree No. 23 of January 8, 1992] are available at:
# http://government.consultant.ru/page.aspx?1223966
# They are in Cyrillic letters (presumably Russian).
# From Arthur David Olson (2012-05-09):
# Regarding the instant when clocks in time-zone-shifting parts of Russia
# changed in September 2011:
#
# One source is
# http://government.ru/gov/results/16355/
# which, according to translate.google.com, begins "Decree of August 31,
# 2011 No. 725" and contains no other dates or "effective date" information.
#
# Another source is
# https://rg.ru/2011/09/06/chas-zona-dok.html
# which, according to translate.google.com, begins "Resolution of the
# Government of the Russian Federation on August 31, 2011 N 725" and also
# contains "Date first official publication: September 6, 2011 Posted on:
# in the 'RG' - Federal Issue No. 5573 September 6, 2011" but which
# does not contain any "effective date" information.
#
# Another source is
# https://en.wikipedia.org/wiki/Oymyakonsky_District#cite_note-RuTime-7
# which, in note 8, contains "Resolution No. 725 of August 31, 2011...
# Effective as of after 7 days following the day of the official publication"
# but which does not contain any reference to September 6, 2011.
#
# The Wikipedia article refers to
# http://base.consultant.ru/cons/cgi/online.cgi?req=doc;base=LAW;n=118896
# which seems to copy the text of the government.ru page.
#
# Tobias Conradi combines Wikipedia's
# "as of after 7 days following the day of the official publication"
# with www.rg.ru's "Date of first official publication: September 6, 2011" to
# get September 13, 2011 as the cutover date (unusually, a Tuesday, as Tobias
# Conradi notes).
#
# None of the sources indicates a time of day for changing clocks.
#
# Go with 2011-09-13 0:00s.
# From Alexander Krivenyshev (2014-07-01):
# According to the Russian news (ITAR-TASS News Agency)
# http://en.itar-tass.com/russia/738562
# the State Duma has approved ... the draft bill on returning to
# winter time standard and return Russia 11 time zones. The new
# regulations will come into effect on October 26, 2014 at 02:00 ...
# http://asozd2.duma.gov.ru/main.nsf/%28Spravka%29?OpenAgent&RN=431985-6&02
# Here is a link where we put together table (based on approved Bill N
# 431985-6) with proposed 11 Russian time zones and corresponding
# areas/cities/administrative centers in the Russian Federation (in English):
# http://www.worldtimezone.com/dst_news/dst_news_russia65.html
#
# From Alexander Krivenyshev (2014-07-22):
# Putin signed the Federal Law 431985-6 ... (in Russian)
# http://itar-tass.com/obschestvo/1333711
# http://www.pravo.gov.ru:8080/page.aspx?111660
# http://www.kremlin.ru/acts/46279
# From October 26, 2014 the new Russian time zone map will look like this:
# http://www.worldtimezone.com/dst_news/dst_news_russia-map-2014-07.html
# From Paul Eggert (2006-03-22):
# Moscow time zone abbreviations after 1919-07-01, and Moscow rules after 1991,
# are from Andrey A. Chernov. The rest is from Shanks & Pottenger,
# except we follow Chernov's report that 1992 DST transitions were Sat
# 23:00, not Sun 02:00s.
#
# From Stanislaw A. Kuzikowski (1994-06-29):
# But now it is some months since Novosibirsk is 3 hours ahead of Moscow!
# I do not know why they have decided to make this change;
# as far as I remember it was done exactly during winter->summer switching
# so we (Novosibirsk) simply did not switch.
#
# From Andrey A. Chernov (1996-10-04):
# 'MSK' and 'MSD' were born and used initially on Moscow computers with
# UNIX-like OSes by several developer groups (e.g. Demos group, Kiae group)....
# The next step was the UUCP network, the Relcom predecessor
# (used mainly for mail), and MSK/MSD was actively used there.
#
# From Chris Carrier (1996-10-30):
# According to a friend of mine who rode the Trans-Siberian Railroad from
# Moscow to Irkutsk in 1995, public air and rail transport in Russia ...
# still follows Moscow time, no matter where in Russia it is located.
#
# For Grozny, Chechnya, we have the following story from
# John Daniszewski, "Scavengers in the Rubble", Los Angeles Times (2001-02-07):
# News - often false - is spread by word of mouth. A rumor that it was
# time to move the clocks back put this whole city out of sync with
# the rest of Russia for two weeks - even soldiers stationed here began
# enforcing curfew at the wrong time.
#
# From Gwillim Law (2001-06-05):
# There's considerable evidence that Sakhalin Island used to be in
# UTC+11, and has changed to UTC+10, in this decade. I start with the
# SSIM, which listed Yuzhno-Sakhalinsk in zone RU10 along with Magadan
# until February 1997, and then in RU9 with Khabarovsk and Vladivostok
# since September 1997.... Although the Kuril Islands are
# administratively part of Sakhalin oblast', they appear to have
# remained on UTC+11 along with Magadan.
# From Marat Nigametzianov (2018-07-16):
# this is link to order from 1956 about timezone in USSR
# http://astro.uni-altai.ru/~orion/blog/2011/11/novyie-granitsyi-chasovyih-poyasov-v-sssr/
#
# From Paul Eggert (2018-07-16):
# Perhaps someone could translate the above-mentioned link and use it
# to correct our data for the ex-Soviet Union. It cites the following:
# «Поясное время и новые границы часовых поясов» / сост. П.Н. Долгов,
# отв. ред. Г.Д. Бурдун - М: Комитет стандартов, мер и измерительных
# приборов при Совете Министров СССР, Междуведомственная комиссия
# единой службы времени, 1956 г.
# This book looks like it would be a helpful resource for the Soviet
# Union through 1956. Although a copy was in the Scientific Library
# of Tomsk State University, I have not been able to track down a copy nearby.
#
# From Stepan Golosunov (2018-07-21):
# http://astro.uni-altai.ru/~orion/blog/2015/05/center-reforma-ischisleniya-vremeni-br-na-territorii-sssr-v-1957-godu-center/
# says that the 1956 decision to change time belts' borders was not
# implemented as planned in 1956 and the change happened in 1957.
# There is also the problem that actual time zones were different from
# the official time belts (and from many time belts' maps) as there were
# numerous exceptions to application of time belt rules. For example,
# https://ru.wikipedia.org/wiki/Московское_время#Перемещение_границы_применения_московского_времени_на_восток
# says that by 1962 there were many regions in the 3rd time belt that
# were on Moscow time, referring to a 1962 map. By 1989 number of such
# exceptions grew considerably.
# From Tim Parenti (2014-07-06):
# The comments detailing the coverage of each Russian zone are meant to assist
# with maintenance only and represent our best guesses as to which regions
# are covered by each zone. They are not meant to be taken as an authoritative
# listing. The region codes listed come from
# https://en.wikipedia.org/w/?title=Federal_subjects_of_Russia&oldid=611810498
# and are used for convenience only; no guarantees are made regarding their
# future stability. ISO 3166-2:RU codes are also listed for first-level
# divisions where available.
# From Tim Parenti (2014-07-03):
# Europe/Kaliningrad covers...
# 39 RU-KGD Kaliningrad Oblast
+# From Paul Eggert (2019-07-25):
+# Although Shanks lists 1945-01-01 as the date for transition from
+# +01/+02 to +02/+03, more likely this is a placeholder. Guess that
+# the transition occurred at 1945-04-10 00:00, which is about when
+# Königsberg surrendered to Soviet troops. (Thanks to Alois Triendl.)
+
# From Paul Eggert (2016-03-18):
# The 1989 transition is from USSR act No. 227 (1989-03-14).
# From Stepan Golosunov (2016-03-07):
# http://www.rgo.ru/ru/kaliningradskoe-oblastnoe-otdelenie/ob-otdelenii/publikacii/kak-nam-zhilos-bez-letnego-vremeni
# confirms that the 1989 change to Moscow-1 was implemented.
# (The article, though, is misattributed to 1990 while saying that
# summer->winter transition would be done on the 24 of September. But
# 1990-09-24 was Monday, while 1989-09-24 was Sunday as expected.)
# ...
# http://www.kaliningradka.ru/site_pc/cherez/index.php?ELEMENT_ID=40091
# says that Kaliningrad switched to Moscow-1 on 1989-03-26, avoided
# at the last moment switch to Moscow-1 on 1991-03-31, switched to
# Moscow on 1991-11-03, switched to Moscow-1 on 1992-01-19.
Zone Europe/Kaliningrad 1:22:00 - LMT 1893 Apr
- 1:00 C-Eur CE%sT 1945
- 2:00 Poland CE%sT 1946
+ 1:00 C-Eur CE%sT 1945 Apr 10
+ 2:00 Poland EE%sT 1946 Apr 7
3:00 Russia MSK/MSD 1989 Mar 26 2:00s
2:00 Russia EE%sT 2011 Mar 27 2:00s
3:00 - +03 2014 Oct 26 2:00s
2:00 - EET
# From Paul Eggert (2016-02-21), per Tim Parenti (2014-07-03) and
# Oscar van Vlijmen (2001-08-25):
# Europe/Moscow covers...
# 01 RU-AD Adygea, Republic of
# 05 RU-DA Dagestan, Republic of
# 06 RU-IN Ingushetia, Republic of
# 07 RU-KB Kabardino-Balkar Republic
# 08 RU-KL Kalmykia, Republic of
# 09 RU-KC Karachay-Cherkess Republic
# 10 RU-KR Karelia, Republic of
# 11 RU-KO Komi Republic
# 12 RU-ME Mari El Republic
# 13 RU-MO Mordovia, Republic of
# 15 RU-SE North Ossetia-Alania, Republic of
# 16 RU-TA Tatarstan, Republic of
# 20 RU-CE Chechen Republic
# 21 RU-CU Chuvash Republic
# 23 RU-KDA Krasnodar Krai
# 26 RU-STA Stavropol Krai
# 29 RU-ARK Arkhangelsk Oblast
# 31 RU-BEL Belgorod Oblast
# 32 RU-BRY Bryansk Oblast
# 33 RU-VLA Vladimir Oblast
# 35 RU-VLG Vologda Oblast
# 36 RU-VOR Voronezh Oblast
# 37 RU-IVA Ivanovo Oblast
# 40 RU-KLU Kaluga Oblast
# 44 RU-KOS Kostroma Oblast
# 46 RU-KRS Kursk Oblast
# 47 RU-LEN Leningrad Oblast
# 48 RU-LIP Lipetsk Oblast
# 50 RU-MOS Moscow Oblast
# 51 RU-MUR Murmansk Oblast
# 52 RU-NIZ Nizhny Novgorod Oblast
# 53 RU-NGR Novgorod Oblast
# 57 RU-ORL Oryol Oblast
# 58 RU-PNZ Penza Oblast
# 60 RU-PSK Pskov Oblast
# 61 RU-ROS Rostov Oblast
# 62 RU-RYA Ryazan Oblast
# 67 RU-SMO Smolensk Oblast
# 68 RU-TAM Tambov Oblast
# 69 RU-TVE Tver Oblast
# 71 RU-TUL Tula Oblast
# 76 RU-YAR Yaroslavl Oblast
# 77 RU-MOW Moscow
# 78 RU-SPE Saint Petersburg
# 83 RU-NEN Nenets Autonomous Okrug
# From Paul Eggert (2016-08-23):
# The Soviets switched to UT-based time in 1919. Decree No. 59
# (1919-02-08) http://istmat.info/node/35567 established UT-based time
# zones, and Decree No. 147 (1919-03-29) http://istmat.info/node/35854
# specified a transition date of 1919-07-01, apparently at 00:00 UT.
# No doubt only the Soviet-controlled regions switched on that date;
# later transitions to UT-based time in other parts of Russia are
# taken from what appear to be guesses by Shanks.
# (Thanks to Alexander Belopolsky for pointers to the decrees.)
# From Stepan Golosunov (2016-03-07):
# 11. Regions-violators, 1981-1982.
# Wikipedia refers to
# http://maps.monetonos.ru/maps/raznoe/Old_Maps/Old_Maps/Articles/022/3_1981.html
# http://besp.narod.ru/nauka_1981_3.htm
#
# The second link provides two articles scanned from the Nauka i Zhizn
# magazine No. 3, 1981 and a scan of the short article attributed to
# the Trud newspaper from February 1982. The first link provides the
# same Nauka i Zhizn articles converted to the text form (but misses
# time belt changes map).
#
# The second Nauka i Zhizn article says that in addition to
# introduction of summer time on 1981-04-01 there are some time belt
# border changes on 1981-10-01, mostly affecting Nenets Autonomous
# Okrug, Krasnoyarsk Krai, Yakutia, Magadan Oblast and Chukotka
# according to the provided map (colored one). In addition to that
# "time violators" (regions which were not using rules of the time
# belts in which they were located) would not be moving off the DST on
# 1981-10-01 to restore the decree time usage. (Komi ASSR was
# supposed to repeat that move in October 1982 to account for the 2
# hour difference.) Map depicting "time violators" before 1981-10-01
# is also provided.
#
# The article from Trud says that 1981-10-01 changes caused problems
# and some territories would be moved to pre-1981-10-01 time by not
# moving to summer time on 1982-04-01. Namely: Dagestan,
# Kabardino-Balkar, Kalmyk, Komi, Mari, Mordovian, North Ossetian,
# Tatar, Chechen-Ingush and Chuvash ASSR, Krasnodar and Stavropol
# krais, Arkhangelsk, Vladimir, Vologda, Voronezh, Gorky, Ivanovo,
# Kostroma, Lipetsk, Penza, Rostov, Ryazan, Tambov, Tyumen and
# Yaroslavl oblasts, Nenets and Evenk autonomous okrugs, Khatangsky
# district of Taymyr Autonomous Okrug. As a result Evenk Autonomous
# Okrug and Khatangsky district of Taymyr Autonomous Okrug would end
# up on Moscow+4, Tyumen Oblast on Moscow+2 and the rest on Moscow
# time.
#
# http://astrozet.net/files/Zones/DOC/RU/1980-925.txt
# attributes the 1982 changes to the Act of the Council of Ministers
# of the USSR No. 126 from 18.02.1982. 1980-925.txt also adds
# Udmurtia to the list of affected territories and lists Khatangsky
# district separately from Taymyr Autonomous Okrug. Probably erroneously.
#
# The affected territories are currently listed under Europe/Moscow,
# Asia/Yekaterinburg and Asia/Krasnoyarsk.
#
# 12. Udmurtia
# The fact that Udmurtia is depicted as a violator in the Nauka i
# Zhizn article hints at Izhevsk being on different time from
# Kuybyshev before 1981-10-01. Udmurtia is not mentioned in the 1989 act.
# http://astrozet.net/files/Zones/DOC/RU/1980-925.txt
# implies Udmurtia was on Moscow time after 1982-04-01.
# Wikipedia implies Udmurtia being on Moscow+1 until 1991.
#
# ...
#
# All Russian zones are supposed to have by default a -1 change at
# 1991-03-31 2:00 (cancellation of the decree time in the USSR) and a +1
# change at 1992-01-19 2:00 (restoration of the decree time in Russia).
#
# There were some exceptions, though.
# Wikipedia says newspapers listed Astrakhan, Saratov, Kirov, Volgograd,
# Izhevsk, Grozny, Kazan and Samara as such exceptions for the 1992
# change. (Different newspapers providing different lists. And some
# lists found in the internet are quite wild.)
#
# And apparently some exceptions were reverted in the last moment.
# http://www.kaliningradka.ru/site_pc/cherez/index.php?ELEMENT_ID=40091
# says that Kaliningrad decided not to be an exception 2 days before the
# 1991-03-31 switch and one person at
# https://izhevsk.ru/forum_light_message/50/682597-m8369040.html
# says he remembers that Samara opted out of the 1992-01-19 exception
# 2 days before the switch.
#
#
# From Paul Eggert (2016-03-18):
# Given the above, we appear to be missing some Zone entries for the
# chaotic early 1980s in Russia. It's not clear what these entries
# should be. For now, sweep this under the rug and just document the
# time in Moscow.
# From Vladimir Karpinsky (2014-07-08):
# LMT in Moscow (before Jul 3, 1916) is 2:30:17, that was defined by Moscow
# Observatory (coordinates: 55° 45' 29.70", 37° 34' 05.30")....
# LMT in Moscow since Jul 3, 1916 is 2:31:01 as a result of new standard.
# (The info is from the book by Byalokoz ... p. 18.)
# The time in St. Petersburg as capital of Russia was defined by
# Pulkov observatory, near St. Petersburg. In 1916 LMT Moscow
# was synchronized with LMT St. Petersburg (+30 minutes), (Pulkov observatory
# coordinates: 59° 46' 18.70", 30° 19' 40.70") so 30° 19' 40.70" >
# 2h01m18.7s = 2:01:19. LMT Moscow = LMT St.Petersburg + 30m 2:01:19 + 0:30 =
# 2:31:19 ...
#
# From Paul Eggert (2014-07-08):
# Milne does not list Moscow, but suggests that its time might be listed in
# Résumés mensuels et annuels des observations météorologiques (1895).
# Presumably this is OCLC 85825704, a journal published with parallel text in
# Russian and French. This source has not been located; go with Karpinsky.
Zone Europe/Moscow 2:30:17 - LMT 1880
2:30:17 - MMT 1916 Jul 3 # Moscow Mean Time
2:31:19 Russia %s 1919 Jul 1 0:00u
3:00 Russia %s 1921 Oct
3:00 Russia MSK/MSD 1922 Oct
2:00 - EET 1930 Jun 21
3:00 Russia MSK/MSD 1991 Mar 31 2:00s
2:00 Russia EE%sT 1992 Jan 19 2:00s
3:00 Russia MSK/MSD 2011 Mar 27 2:00s
4:00 - MSK 2014 Oct 26 2:00s
3:00 - MSK
# From Paul Eggert (2016-12-06):
# Europe/Simferopol covers Crimea.
Zone Europe/Simferopol 2:16:24 - LMT 1880
2:16 - SMT 1924 May 2 # Simferopol Mean T
2:00 - EET 1930 Jun 21
3:00 - MSK 1941 Nov
1:00 C-Eur CE%sT 1944 Apr 13
3:00 Russia MSK/MSD 1990
3:00 - MSK 1990 Jul 1 2:00
2:00 - EET 1992
# Central Crimea used Moscow time 1994/1997.
#
# From Paul Eggert (2006-03-22):
# The _Economist_ (1994-05-28, p 45) reports that central Crimea switched
# from Kiev to Moscow time sometime after the January 1994 elections.
# Shanks (1999) says "date of change uncertain", but implies that it happened
# sometime between the 1994 DST switches. Shanks & Pottenger simply say
# 1994-09-25 03:00, but that can't be right. For now, guess it
# changed in May.
2:00 E-Eur EE%sT 1994 May
# From IATA SSIM (1994/1997), which also says that Kerch is still like Kiev.
3:00 E-Eur MSK/MSD 1996 Mar 31 0:00s
3:00 1:00 MSD 1996 Oct 27 3:00s
# IATA SSIM (1997-09) says Crimea switched to EET/EEST.
# Assume it happened in March by not changing the clocks.
3:00 Russia MSK/MSD 1997
3:00 - MSK 1997 Mar lastSun 1:00u
# From Alexander Krivenyshev (2014-03-17):
# time change at 2:00 (2am) on March 30, 2014
# https://vz.ru/news/2014/3/17/677464.html
# From Paul Eggert (2014-03-30):
# Simferopol and Sevastopol reportedly changed their central town clocks
# late the previous day, but this appears to have been ceremonial
# and the discrepancies are small enough to not worry about.
2:00 EU EE%sT 2014 Mar 30 2:00
4:00 - MSK 2014 Oct 26 2:00s
3:00 - MSK
# From Paul Eggert (2016-03-18):
# Europe/Astrakhan covers:
# 30 RU-AST Astrakhan Oblast
#
# The 1989 transition is from USSR act No. 227 (1989-03-14).
# From Alexander Krivenyshev (2016-01-12):
# On February 10, 2016 Astrakhan Oblast got approval by the Federation
# Council to change its time zone to UTC+4 (from current UTC+3 Moscow time)....
# This Federal Law shall enter into force on 27 March 2016 at 02:00.
# From Matt Johnson (2016-03-09):
# http://publication.pravo.gov.ru/Document/View/0001201602150056
Zone Europe/Astrakhan 3:12:12 - LMT 1924 May
3:00 - +03 1930 Jun 21
4:00 Russia +04/+05 1989 Mar 26 2:00s
3:00 Russia +03/+04 1991 Mar 31 2:00s
4:00 - +04 1992 Mar 29 2:00s
3:00 Russia +03/+04 2011 Mar 27 2:00s
4:00 - +04 2014 Oct 26 2:00s
3:00 - +03 2016 Mar 27 2:00s
4:00 - +04
# From Paul Eggert (2016-11-11):
# Europe/Volgograd covers:
# 34 RU-VGG Volgograd Oblast
# The 1988 transition is from USSR act No. 5 (1988-01-04).
# From Alexander Fetisov (2018-09-20):
# Volgograd region in southern Russia (Europe/Volgograd) change
# timezone from UTC+3 to UTC+4 from 28oct2018.
# http://sozd.parliament.gov.ru/bill/452878-7
#
# From Stepan Golosunov (2018-10-11):
# The law has been published today on
# http://publication.pravo.gov.ru/Document/View/0001201810110037
Zone Europe/Volgograd 2:57:40 - LMT 1920 Jan 3
3:00 - +03 1930 Jun 21
4:00 - +04 1961 Nov 11
4:00 Russia +04/+05 1988 Mar 27 2:00s
3:00 Russia +03/+04 1991 Mar 31 2:00s
4:00 - +04 1992 Mar 29 2:00s
3:00 Russia +03/+04 2011 Mar 27 2:00s
4:00 - +04 2014 Oct 26 2:00s
3:00 - +03 2018 Oct 28 2:00s
4:00 - +04
# From Paul Eggert (2016-11-11):
# Europe/Saratov covers:
# 64 RU-SAR Saratov Oblast
# From Yuri Konotopov (2016-11-11):
# Dec 4, 2016 02:00 UTC+3.... Saratov Region's local time will be ... UTC+4.
# From Stepan Golosunov (2016-11-11):
# ... Byalokoz listed Saratov on 03:04:18.
# From Stepan Golosunov (2016-11-22):
# http://publication.pravo.gov.ru/Document/View/0001201611220031
Zone Europe/Saratov 3:04:18 - LMT 1919 Jul 1 0:00u
3:00 - +03 1930 Jun 21
4:00 Russia +04/+05 1988 Mar 27 2:00s
3:00 Russia +03/+04 1991 Mar 31 2:00s
4:00 - +04 1992 Mar 29 2:00s
3:00 Russia +03/+04 2011 Mar 27 2:00s
4:00 - +04 2014 Oct 26 2:00s
3:00 - +03 2016 Dec 4 2:00s
4:00 - +04
# From Paul Eggert (2016-03-18):
# Europe/Kirov covers:
# 43 RU-KIR Kirov Oblast
# The 1989 transition is from USSR act No. 227 (1989-03-14).
#
Zone Europe/Kirov 3:18:48 - LMT 1919 Jul 1 0:00u
3:00 - +03 1930 Jun 21
4:00 Russia +04/+05 1989 Mar 26 2:00s
3:00 Russia +03/+04 1991 Mar 31 2:00s
4:00 - +04 1992 Mar 29 2:00s
3:00 Russia +03/+04 2011 Mar 27 2:00s
4:00 - +04 2014 Oct 26 2:00s
3:00 - +03
# From Tim Parenti (2014-07-03), per Oscar van Vlijmen (2001-08-25):
# Europe/Samara covers...
# 18 RU-UD Udmurt Republic
# 63 RU-SAM Samara Oblast
# From Paul Eggert (2016-03-18):
# Byalokoz 1919 says Samara was 3:20:20.
# The 1989 transition is from USSR act No. 227 (1989-03-14).
Zone Europe/Samara 3:20:20 - LMT 1919 Jul 1 0:00u
3:00 - +03 1930 Jun 21
4:00 - +04 1935 Jan 27
4:00 Russia +04/+05 1989 Mar 26 2:00s
3:00 Russia +03/+04 1991 Mar 31 2:00s
2:00 Russia +02/+03 1991 Sep 29 2:00s
3:00 - +03 1991 Oct 20 3:00
4:00 Russia +04/+05 2010 Mar 28 2:00s
3:00 Russia +03/+04 2011 Mar 27 2:00s
4:00 - +04
# From Paul Eggert (2016-03-18):
# Europe/Ulyanovsk covers:
# 73 RU-ULY Ulyanovsk Oblast
# The 1989 transition is from USSR act No. 227 (1989-03-14).
# From Alexander Krivenyshev (2016-02-17):
# Ulyanovsk ... on their way to change time zones by March 27, 2016 at 2am.
# Ulyanovsk Oblast ... from MSK to MSK+1 (UTC+3 to UTC+4) ...
# 920582-6 ... 02/17/2016 The State Duma passed the bill in the first reading.
# From Matt Johnson (2016-03-09):
# http://publication.pravo.gov.ru/Document/View/0001201603090051
Zone Europe/Ulyanovsk 3:13:36 - LMT 1919 Jul 1 0:00u
3:00 - +03 1930 Jun 21
4:00 Russia +04/+05 1989 Mar 26 2:00s
3:00 Russia +03/+04 1991 Mar 31 2:00s
2:00 Russia +02/+03 1992 Jan 19 2:00s
3:00 Russia +03/+04 2011 Mar 27 2:00s
4:00 - +04 2014 Oct 26 2:00s
3:00 - +03 2016 Mar 27 2:00s
4:00 - +04
# From Tim Parenti (2014-07-03), per Oscar van Vlijmen (2001-08-25):
# Asia/Yekaterinburg covers...
# 02 RU-BA Bashkortostan, Republic of
# 90 RU-PER Perm Krai
# 45 RU-KGN Kurgan Oblast
# 56 RU-ORE Orenburg Oblast
# 66 RU-SVE Sverdlovsk Oblast
# 72 RU-TYU Tyumen Oblast
# 74 RU-CHE Chelyabinsk Oblast
# 86 RU-KHM Khanty-Mansi Autonomous Okrug - Yugra
# 89 RU-YAN Yamalo-Nenets Autonomous Okrug
#
# Note: Effective 2005-12-01, (59) Perm Oblast and (81) Komi-Permyak
# Autonomous Okrug merged to form (90, RU-PER) Perm Krai.
# Milne says Yekaterinburg was 4:02:32.9; round to nearest.
# Byalokoz 1919 says its provincial time was based on Perm, at 3:45:05.
# Assume it switched on 1916-07-03, the time of the new standard.
# The 1919 and 1930 transitions are from Shanks.
Zone Asia/Yekaterinburg 4:02:33 - LMT 1916 Jul 3
3:45:05 - PMT 1919 Jul 15 4:00
4:00 - +04 1930 Jun 21
5:00 Russia +05/+06 1991 Mar 31 2:00s
4:00 Russia +04/+05 1992 Jan 19 2:00s
5:00 Russia +05/+06 2011 Mar 27 2:00s
6:00 - +06 2014 Oct 26 2:00s
5:00 - +05
# From Tim Parenti (2014-07-03), per Oscar van Vlijmen (2001-08-25):
# Asia/Omsk covers...
# 55 RU-OMS Omsk Oblast
# Byalokoz 1919 says Omsk was 4:53:30.
Zone Asia/Omsk 4:53:30 - LMT 1919 Nov 14
5:00 - +05 1930 Jun 21
6:00 Russia +06/+07 1991 Mar 31 2:00s
5:00 Russia +05/+06 1992 Jan 19 2:00s
6:00 Russia +06/+07 2011 Mar 27 2:00s
7:00 - +07 2014 Oct 26 2:00s
6:00 - +06
# From Paul Eggert (2016-02-22):
# Asia/Barnaul covers:
# 04 RU-AL Altai Republic
# 22 RU-ALT Altai Krai
# Data before 1991 are from Shanks & Pottenger.
# From Stepan Golosunov (2016-03-07):
# Letter of Bank of Russia from 1995-05-25
# http://www.bestpravo.ru/rossijskoje/lj-akty/y3a.htm
# suggests that Altai Republic transitioned to Moscow+3 on
# 1995-05-28.
#
# https://regnum.ru/news/society/1957270.html
# has some historical data for Altai Krai:
# before 1957: west part on UT+6, east on UT+7
# after 1957: UT+7
# since 1995: UT+6
# http://barnaul.rusplt.ru/index/pochemu_altajskij_kraj_okazalsja_v_neprivychnom_chasovom_pojase-17648.html
# confirms that and provides more details including 1995-05-28 transition date.
# From Alexander Krivenyshev (2016-02-17):
# Altai Krai and Altai Republic on their way to change time zones
# by March 27, 2016 at 2am....
# Altai Republic / Gorno-Altaysk MSK+3 to MSK+4 (UTC+6 to UTC+7) ...
# Altai Krai / Barnaul MSK+3 to MSK+4 (UTC+6 to UTC+7)
# From Matt Johnson (2016-03-09):
# http://publication.pravo.gov.ru/Document/View/0001201603090043
# http://publication.pravo.gov.ru/Document/View/0001201603090038
Zone Asia/Barnaul 5:35:00 - LMT 1919 Dec 10
6:00 - +06 1930 Jun 21
7:00 Russia +07/+08 1991 Mar 31 2:00s
6:00 Russia +06/+07 1992 Jan 19 2:00s
7:00 Russia +07/+08 1995 May 28
6:00 Russia +06/+07 2011 Mar 27 2:00s
7:00 - +07 2014 Oct 26 2:00s
6:00 - +06 2016 Mar 27 2:00s
7:00 - +07
# From Paul Eggert (2016-03-18):
# Asia/Novosibirsk covers:
# 54 RU-NVS Novosibirsk Oblast
# From Stepan Golosunov (2016-05-30):
# http://asozd2.duma.gov.ru/main.nsf/(Spravka)?OpenAgent&RN=1085784-6
# moves Novosibirsk oblast from UTC+6 to UTC+7.
# From Stepan Golosunov (2016-07-04):
# The law was signed yesterday and published today on
# http://publication.pravo.gov.ru/Document/View/0001201607040064
Zone Asia/Novosibirsk 5:31:40 - LMT 1919 Dec 14 6:00
6:00 - +06 1930 Jun 21
7:00 Russia +07/+08 1991 Mar 31 2:00s
6:00 Russia +06/+07 1992 Jan 19 2:00s
7:00 Russia +07/+08 1993 May 23 # say Shanks & P.
6:00 Russia +06/+07 2011 Mar 27 2:00s
7:00 - +07 2014 Oct 26 2:00s
6:00 - +06 2016 Jul 24 2:00s
7:00 - +07
# From Paul Eggert (2016-03-18):
# Asia/Tomsk covers:
# 70 RU-TOM Tomsk Oblast
# From Stepan Golosunov (2016-03-24):
# Byalokoz listed Tomsk at 5:39:51.
# From Stanislaw A. Kuzikowski (1994-06-29):
# Tomsk is still 4 hours ahead of Moscow.
# From Stepan Golosunov (2016-03-19):
# http://pravo.gov.ru/proxy/ips/?docbody=&nd=102075743
# (fifth time belt being UTC+5+1(decree time)
# / UTC+5+1(decree time)+1(summer time)) ...
# Note that time belts (numbered from 2 (Moscow) to 12 according to their
# GMT/UTC offset and having too many exceptions like regions formally
# belonging to one belt but using time from another) were replaced
# with time zones in 2011 with different numbering (there was a
# 2-hour gap between second and third zones in 2011-2014).
# From Stepan Golosunov (2016-04-12):
# http://asozd2.duma.gov.ru/main.nsf/(SpravkaNew)?OpenAgent&RN=1006865-6
# This bill was approved in the first reading today. It moves Tomsk oblast
# from UTC+6 to UTC+7 and is supposed to come into effect on 2016-05-29 at
# 2:00. The bill needs to be approved in the second and the third readings by
# the State Duma, approved by the Federation Council, signed by the President
# and published to become a law. Minor changes in the text are to be expected
# before the second reading (references need to be updated to account for the
# recent changes).
#
# Judging by the ultra-short one-day amendments period, recent similar laws,
# the State Duma schedule and the Federation Council schedule
# http://www.duma.gov.ru/legislative/planning/day-shedule/por_vesna_2016/
# http://council.gov.ru/activity/meetings/schedule/63303
# I speculate that the final text of the bill will be proposed tomorrow, the
# bill will be approved in the second and the third readings on Friday,
# approved by the Federation Council on 2016-04-20, signed by the President and
# published as a law around 2016-04-26.
# From Matt Johnson (2016-04-26):
# http://publication.pravo.gov.ru/Document/View/0001201604260048
Zone Asia/Tomsk 5:39:51 - LMT 1919 Dec 22
6:00 - +06 1930 Jun 21
7:00 Russia +07/+08 1991 Mar 31 2:00s
6:00 Russia +06/+07 1992 Jan 19 2:00s
7:00 Russia +07/+08 2002 May 1 3:00
6:00 Russia +06/+07 2011 Mar 27 2:00s
7:00 - +07 2014 Oct 26 2:00s
6:00 - +06 2016 May 29 2:00s
7:00 - +07
# From Tim Parenti (2014-07-03):
# Asia/Novokuznetsk covers...
# 42 RU-KEM Kemerovo Oblast
# From Alexander Krivenyshev (2009-10-13):
# Kemerovo oblast' (Kemerovo region) in Russia will change current time zone on
# March 28, 2010:
# from current Russia Zone 6 - Krasnoyarsk Time Zone (KRA) UTC +0700
# to Russia Zone 5 - Novosibirsk Time Zone (NOV) UTC +0600
#
# This is according to Government of Russia decree No. 740, on September
# 14, 2009 "Application in the territory of the Kemerovo region the Fifth
# time zone." ("Russia Zone 5" or old "USSR Zone 5" is GMT +0600)
#
# Russian Government web site (Russian language)
# http://www.government.ru/content/governmentactivity/rfgovernmentdecisions/archive/2009/09/14/991633.htm
# or Russian-English translation by WorldTimeZone.com with reference
# map to local region and new Russia Time Zone map after March 28, 2010
# http://www.worldtimezone.com/dst_news/dst_news_russia03.html
#
# Thus, when Russia will switch to DST on the night of March 28, 2010
# Kemerovo region (Kemerovo oblast') will not change the clock.
# From Tim Parenti (2014-07-02), per Alexander Krivenyshev (2014-07-02):
# The Kemerovo region will remain at UTC+7 through the 2014-10-26 change, thus
# realigning itself with KRAT.
Zone Asia/Novokuznetsk 5:48:48 - LMT 1924 May 1
6:00 - +06 1930 Jun 21
7:00 Russia +07/+08 1991 Mar 31 2:00s
6:00 Russia +06/+07 1992 Jan 19 2:00s
7:00 Russia +07/+08 2010 Mar 28 2:00s
6:00 Russia +06/+07 2011 Mar 27 2:00s
7:00 - +07
# From Tim Parenti (2014-07-03), per Oscar van Vlijmen (2001-08-25):
# Asia/Krasnoyarsk covers...
# 17 RU-TY Tuva Republic
# 19 RU-KK Khakassia, Republic of
# 24 RU-KYA Krasnoyarsk Krai
#
# Note: Effective 2007-01-01, (88) Evenk Autonomous Okrug and (84) Taymyr
# Autonomous Okrug were merged into (24, RU-KYA) Krasnoyarsk Krai.
# Byalokoz 1919 says Krasnoyarsk was 6:11:26.
Zone Asia/Krasnoyarsk 6:11:26 - LMT 1920 Jan 6
6:00 - +06 1930 Jun 21
7:00 Russia +07/+08 1991 Mar 31 2:00s
6:00 Russia +06/+07 1992 Jan 19 2:00s
7:00 Russia +07/+08 2011 Mar 27 2:00s
8:00 - +08 2014 Oct 26 2:00s
7:00 - +07
# From Tim Parenti (2014-07-03), per Oscar van Vlijmen (2001-08-25):
# Asia/Irkutsk covers...
# 03 RU-BU Buryatia, Republic of
# 38 RU-IRK Irkutsk Oblast
#
# Note: Effective 2008-01-01, (85) Ust-Orda Buryat Autonomous Okrug was
# merged into (38, RU-IRK) Irkutsk Oblast.
# Milne 1899 says Irkutsk was 6:57:15.
# Byalokoz 1919 says Irkutsk was 6:57:05.
# Go with Byalokoz.
Zone Asia/Irkutsk 6:57:05 - LMT 1880
6:57:05 - IMT 1920 Jan 25 # Irkutsk Mean Time
7:00 - +07 1930 Jun 21
8:00 Russia +08/+09 1991 Mar 31 2:00s
7:00 Russia +07/+08 1992 Jan 19 2:00s
8:00 Russia +08/+09 2011 Mar 27 2:00s
9:00 - +09 2014 Oct 26 2:00s
8:00 - +08
# From Tim Parenti (2014-07-06):
# Asia/Chita covers...
# 92 RU-ZAB Zabaykalsky Krai
#
# Note: Effective 2008-03-01, (75) Chita Oblast and (80) Agin-Buryat
# Autonomous Okrug merged to form (92, RU-ZAB) Zabaykalsky Krai.
# From Alexander Krivenyshev (2016-01-02):
# [The] time zone in the Trans-Baikal Territory (Zabaykalsky Krai) -
# Asia/Chita [is changing] from UTC+8 to UTC+9. Effective date will
# be March 27, 2016 at 2:00am....
# http://publication.pravo.gov.ru/Document/View/0001201512300107
Zone Asia/Chita 7:33:52 - LMT 1919 Dec 15
8:00 - +08 1930 Jun 21
9:00 Russia +09/+10 1991 Mar 31 2:00s
8:00 Russia +08/+09 1992 Jan 19 2:00s
9:00 Russia +09/+10 2011 Mar 27 2:00s
10:00 - +10 2014 Oct 26 2:00s
8:00 - +08 2016 Mar 27 2:00
9:00 - +09
# From Tim Parenti (2014-07-03), per Oscar van Vlijmen (2009-11-29):
# Asia/Yakutsk covers...
# 28 RU-AMU Amur Oblast
#
# ...and parts of (14, RU-SA) Sakha (Yakutia) Republic:
# 14-02 **** Aldansky District
# 14-04 **** Amginsky District
# 14-05 **** Anabarsky District
# 14-06 **** Bulunsky District
# 14-07 **** Verkhnevilyuysky District
# 14-10 **** Vilyuysky District
# 14-11 **** Gorny District
# 14-12 **** Zhigansky District
# 14-13 **** Kobyaysky District
# 14-14 **** Lensky District
# 14-15 **** Megino-Kangalassky District
# 14-16 **** Mirninsky District
# 14-18 **** Namsky District
# 14-19 **** Neryungrinsky District
# 14-21 **** Nyurbinsky District
# 14-23 **** Olenyoksky District
# 14-24 **** Olyokminsky District
# 14-26 **** Suntarsky District
# 14-27 **** Tattinsky District
# 14-29 **** Ust-Aldansky District
# 14-32 **** Khangalassky District
# 14-33 **** Churapchinsky District
# 14-34 **** Eveno-Bytantaysky National District
# From Tim Parenti (2014-07-03):
# Our commentary seems to have lost mention of (14-19) Neryungrinsky District.
# Since the surrounding districts of Sakha are all YAKT, assume this is, too.
# Also assume its history has been the same as the rest of Asia/Yakutsk.
# Byalokoz 1919 says Yakutsk was 8:38:58.
Zone Asia/Yakutsk 8:38:58 - LMT 1919 Dec 15
8:00 - +08 1930 Jun 21
9:00 Russia +09/+10 1991 Mar 31 2:00s
8:00 Russia +08/+09 1992 Jan 19 2:00s
9:00 Russia +09/+10 2011 Mar 27 2:00s
10:00 - +10 2014 Oct 26 2:00s
9:00 - +09
# From Tim Parenti (2014-07-03), per Oscar van Vlijmen (2009-11-29):
# Asia/Vladivostok covers...
# 25 RU-PRI Primorsky Krai
# 27 RU-KHA Khabarovsk Krai
# 79 RU-YEV Jewish Autonomous Oblast
#
# ...and parts of (14, RU-SA) Sakha (Yakutia) Republic:
# 14-09 **** Verkhoyansky District
# 14-31 **** Ust-Yansky District
# Milne 1899 says Vladivostok was 8:47:33.5.
# Byalokoz 1919 says Vladivostok was 8:47:31.
# Go with Byalokoz.
Zone Asia/Vladivostok 8:47:31 - LMT 1922 Nov 15
9:00 - +09 1930 Jun 21
10:00 Russia +10/+11 1991 Mar 31 2:00s
9:00 Russia +09/+10 1992 Jan 19 2:00s
10:00 Russia +10/+11 2011 Mar 27 2:00s
11:00 - +11 2014 Oct 26 2:00s
10:00 - +10
# From Tim Parenti (2014-07-03):
# Asia/Khandyga covers parts of (14, RU-SA) Sakha (Yakutia) Republic:
# 14-28 **** Tomponsky District
# 14-30 **** Ust-Maysky District
# From Arthur David Olson (2012-05-09):
# Tomponskij and Ust'-Majskij switched from Vladivostok time to Yakutsk time
# in 2011.
# From Paul Eggert (2012-11-25):
# Shanks and Pottenger (2003) has Khandyga on Yakutsk time.
# Make a wild guess that it switched to Vladivostok time in 2004.
# This transition is no doubt wrong, but we have no better info.
Zone Asia/Khandyga 9:02:13 - LMT 1919 Dec 15
8:00 - +08 1930 Jun 21
9:00 Russia +09/+10 1991 Mar 31 2:00s
8:00 Russia +08/+09 1992 Jan 19 2:00s
9:00 Russia +09/+10 2004
10:00 Russia +10/+11 2011 Mar 27 2:00s
11:00 - +11 2011 Sep 13 0:00s # Decree 725?
10:00 - +10 2014 Oct 26 2:00s
9:00 - +09
# From Tim Parenti (2014-07-03):
# Asia/Sakhalin covers...
# 65 RU-SAK Sakhalin Oblast
# ...with the exception of:
# 65-11 **** Severo-Kurilsky District (North Kuril Islands)
# From Matt Johnson (2016-02-22):
# Asia/Sakhalin is moving (in entirety) from UTC+10 to UTC+11 ...
# (2016-03-09):
# http://publication.pravo.gov.ru/Document/View/0001201603090044
# The Zone name should be Asia/Yuzhno-Sakhalinsk, but that's too long.
Zone Asia/Sakhalin 9:30:48 - LMT 1905 Aug 23
9:00 - +09 1945 Aug 25
11:00 Russia +11/+12 1991 Mar 31 2:00s # Sakhalin T
10:00 Russia +10/+11 1992 Jan 19 2:00s
11:00 Russia +11/+12 1997 Mar lastSun 2:00s
10:00 Russia +10/+11 2011 Mar 27 2:00s
11:00 - +11 2014 Oct 26 2:00s
10:00 - +10 2016 Mar 27 2:00s
11:00 - +11
# From Tim Parenti (2014-07-03), per Oscar van Vlijmen (2009-11-29):
# Asia/Magadan covers...
# 49 RU-MAG Magadan Oblast
# From Tim Parenti (2014-07-06), per Alexander Krivenyshev (2014-07-02):
# Magadan Oblast is moving from UTC+12 to UTC+10 on 2014-10-26; however,
# several districts of Sakha Republic as well as Severo-Kurilsky District of
# the Sakhalin Oblast (also known as the North Kuril Islands), represented
# until now by Asia/Magadan, will instead move to UTC+11. These regions will
# need their own zone.
# From Alexander Krivenyshev (2016-03-27):
# ... draft bill 948300-6 to change its time zone from UTC+10 to UTC+11 ...
# will take ... effect ... on April 24, 2016 at 2 o'clock
#
# From Matt Johnson (2016-04-05):
# ... signed by the President today ...
# http://publication.pravo.gov.ru/Document/View/0001201604050038
Zone Asia/Magadan 10:03:12 - LMT 1924 May 2
10:00 - +10 1930 Jun 21 # Magadan Time
11:00 Russia +11/+12 1991 Mar 31 2:00s
10:00 Russia +10/+11 1992 Jan 19 2:00s
11:00 Russia +11/+12 2011 Mar 27 2:00s
12:00 - +12 2014 Oct 26 2:00s
10:00 - +10 2016 Apr 24 2:00s
11:00 - +11
# From Tim Parenti (2014-07-06):
# Asia/Srednekolymsk covers parts of (14, RU-SA) Sakha (Yakutia) Republic:
# 14-01 **** Abyysky District
# 14-03 **** Allaikhovsky District
# 14-08 **** Verkhnekolymsky District
# 14-17 **** Momsky District
# 14-20 **** Nizhnekolymsky District
# 14-25 **** Srednekolymsky District
#
# ...and parts of (65, RU-SAK) Sakhalin Oblast:
# 65-11 **** Severo-Kurilsky District (North Kuril Islands)
# From Tim Parenti (2014-07-02):
# Oymyakonsky District of Sakha Republic (represented by Ust-Nera), along with
# most of Sakhalin Oblast (represented by Sakhalin) will be moving to UTC+10 on
# 2014-10-26 to stay aligned with VLAT/SAKT; however, Severo-Kurilsky District
# of the Sakhalin Oblast (also known as the North Kuril Islands, represented by
# Severo-Kurilsk) will remain on UTC+11.
# From Tim Parenti (2014-07-06):
# Assume North Kuril Islands have history like Magadan before 2011-03-27.
# There is a decent chance this is wrong, in which case a new zone
# Asia/Severo-Kurilsk would become necessary.
#
# Srednekolymsk and Zyryanka are the most populous places amongst these
# districts, but have very similar populations. In fact, Wikipedia currently
# lists them both as having 3528 people, exactly 1668 males and 1860 females
# each! (Yikes!)
# https://en.wikipedia.org/w/?title=Srednekolymsky_District&oldid=603435276
# https://en.wikipedia.org/w/?title=Verkhnekolymsky_District&oldid=594378493
# Assume this is a mistake, albeit an amusing one.
#
# Looking at censuses, the populations of the two municipalities seem to have
# fluctuated recently. Zyryanka was more populous than Srednekolymsk in the
# 1989 and 2002 censuses, but Srednekolymsk was more populous in the most
# recent (2010) census, 3525 to 3170. (See pages 195 and 197 of
# http://www.gks.ru/free_doc/new_site/perepis2010/croc/Documents/Vol1/pub-01-05.pdf
# in Russian.) In addition, Srednekolymsk appears to be a much older
# settlement and the population of Zyryanka seems to be declining.
# Go with Srednekolymsk.
Zone Asia/Srednekolymsk 10:14:52 - LMT 1924 May 2
10:00 - +10 1930 Jun 21
11:00 Russia +11/+12 1991 Mar 31 2:00s
10:00 Russia +10/+11 1992 Jan 19 2:00s
11:00 Russia +11/+12 2011 Mar 27 2:00s
12:00 - +12 2014 Oct 26 2:00s
11:00 - +11
# From Tim Parenti (2014-07-03):
# Asia/Ust-Nera covers parts of (14, RU-SA) Sakha (Yakutia) Republic:
# 14-22 **** Oymyakonsky District
# From Arthur David Olson (2012-05-09):
# Ojmyakonskij [and the Kuril Islands] switched from
# Magadan time to Vladivostok time in 2011.
#
# From Tim Parenti (2014-07-06), per Alexander Krivenyshev (2014-07-02):
# It's unlikely that any of the Kuril Islands were involved in such a switch,
# as the South and Middle Kurils have been on UTC+11 (SAKT) with the rest of
# Sakhalin Oblast since at least 2011-09, and the North Kurils have been on
# UTC+12 since at least then, too.
Zone Asia/Ust-Nera 9:32:54 - LMT 1919 Dec 15
8:00 - +08 1930 Jun 21
9:00 Russia +09/+10 1981 Apr 1
11:00 Russia +11/+12 1991 Mar 31 2:00s
10:00 Russia +10/+11 1992 Jan 19 2:00s
11:00 Russia +11/+12 2011 Mar 27 2:00s
12:00 - +12 2011 Sep 13 0:00s # Decree 725?
11:00 - +11 2014 Oct 26 2:00s
10:00 - +10
# From Tim Parenti (2014-07-03), per Oscar van Vlijmen (2001-08-25):
# Asia/Kamchatka covers...
# 91 RU-KAM Kamchatka Krai
#
# Note: Effective 2007-07-01, (41) Kamchatka Oblast and (82) Koryak
# Autonomous Okrug merged to form (91, RU-KAM) Kamchatka Krai.
# The Zone name should be Asia/Petropavlovsk-Kamchatski or perhaps
# Asia/Petropavlovsk-Kamchatsky, but these are too long.
Zone Asia/Kamchatka 10:34:36 - LMT 1922 Nov 10
11:00 - +11 1930 Jun 21
12:00 Russia +12/+13 1991 Mar 31 2:00s
11:00 Russia +11/+12 1992 Jan 19 2:00s
12:00 Russia +12/+13 2010 Mar 28 2:00s
11:00 Russia +11/+12 2011 Mar 27 2:00s
12:00 - +12
# From Tim Parenti (2014-07-03):
# Asia/Anadyr covers...
# 87 RU-CHU Chukotka Autonomous Okrug
Zone Asia/Anadyr 11:49:56 - LMT 1924 May 2
12:00 - +12 1930 Jun 21
13:00 Russia +13/+14 1982 Apr 1 0:00s
12:00 Russia +12/+13 1991 Mar 31 2:00s
11:00 Russia +11/+12 1992 Jan 19 2:00s
12:00 Russia +12/+13 2010 Mar 28 2:00s
11:00 Russia +11/+12 2011 Mar 27 2:00s
12:00 - +12
# San Marino
# See Europe/Rome.
# Serbia
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Belgrade 1:22:00 - LMT 1884
1:00 - CET 1941 Apr 18 23:00
1:00 C-Eur CE%sT 1945
1:00 - CET 1945 May 8 2:00s
1:00 1:00 CEST 1945 Sep 16 2:00s
# Metod Koželj reports that the legal date of
# transition to EU rules was 1982-11-27, for all of Yugoslavia at the time.
# Shanks & Pottenger don't give as much detail, so go with Koželj.
1:00 - CET 1982 Nov 27
1:00 EU CE%sT
Link Europe/Belgrade Europe/Ljubljana # Slovenia
Link Europe/Belgrade Europe/Podgorica # Montenegro
Link Europe/Belgrade Europe/Sarajevo # Bosnia and Herzegovina
Link Europe/Belgrade Europe/Skopje # North Macedonia
Link Europe/Belgrade Europe/Zagreb # Croatia
# Slovakia
Link Europe/Prague Europe/Bratislava
# Slovenia
# See Europe/Belgrade.
# Spain
#
# From Paul Eggert (2016-12-14):
#
# The source for Europe/Madrid before 2013 is:
# Planesas P. La hora oficial en España y sus cambios.
# Anuario del Observatorio Astronómico de Madrid (2013, in Spanish).
# http://astronomia.ign.es/rknowsys-theme/images/webAstro/paginas/documentos/Anuario/lahoraoficialenespana.pdf
# As this source says that historical time in the Canaries is obscure,
# and it does not discuss Ceuta, stick with Shanks for now for that data.
#
# In the 1918 and 1919 fallback transitions in Spain, the clock for
# the hour-longer day officially kept going after midnight, so that
# the repeated instances of that day's 00:00 hour were 24 hours apart,
# with a fallback transition from the second occurrence of 00:59... to
# the next day's 00:00. Our data format cannot represent this
# directly, and instead repeats the first hour of the next day, with a
# fallback transition from the next day's 00:59... to 00:00.
# From Michael Deckers (2016-12-15):
# The Royal Decree of 1900-06-26 quoted by Planesas, online at
# https://www.boe.es/datos/pdfs/BOE//1900/209/A00383-00384.pdf
# says in its article 5 (my translation):
# These dispositions will enter into force beginning with the
# instant at which, according to the time indicated in article 1,
# the 1st day of January of 1901 will begin.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Spain 1918 only - Apr 15 23:00 1:00 S
Rule Spain 1918 1919 - Oct 6 24:00s 0 -
Rule Spain 1919 only - Apr 6 23:00 1:00 S
Rule Spain 1924 only - Apr 16 23:00 1:00 S
Rule Spain 1924 only - Oct 4 24:00s 0 -
Rule Spain 1926 only - Apr 17 23:00 1:00 S
Rule Spain 1926 1929 - Oct Sat>=1 24:00s 0 -
Rule Spain 1927 only - Apr 9 23:00 1:00 S
Rule Spain 1928 only - Apr 15 0:00 1:00 S
Rule Spain 1929 only - Apr 20 23:00 1:00 S
# Republican Spain during the civil war; it controlled Madrid until 1939-03-28.
Rule Spain 1937 only - Jun 16 23:00 1:00 S
Rule Spain 1937 only - Oct 2 24:00s 0 -
Rule Spain 1938 only - Apr 2 23:00 1:00 S
Rule Spain 1938 only - Apr 30 23:00 2:00 M
Rule Spain 1938 only - Oct 2 24:00 1:00 S
# The following rules are for unified Spain again.
#
# Planesas does not say what happened in Madrid between its fall on
# 1939-03-28 and the Nationalist spring-forward transition on
# 1939-04-15. For lack of better info, assume Madrid's clocks did not
# change during that period.
#
# The first rule is commented out, as it is redundant for Republican Spain.
#Rule Spain 1939 only - Apr 15 23:00 1:00 S
Rule Spain 1939 only - Oct 7 24:00s 0 -
Rule Spain 1942 only - May 2 23:00 1:00 S
Rule Spain 1942 only - Sep 1 1:00 0 -
Rule Spain 1943 1946 - Apr Sat>=13 23:00 1:00 S
Rule Spain 1943 1944 - Oct Sun>=1 1:00 0 -
Rule Spain 1945 1946 - Sep lastSun 1:00 0 -
Rule Spain 1949 only - Apr 30 23:00 1:00 S
Rule Spain 1949 only - Oct 2 1:00 0 -
Rule Spain 1974 1975 - Apr Sat>=12 23:00 1:00 S
Rule Spain 1974 1975 - Oct Sun>=1 1:00 0 -
Rule Spain 1976 only - Mar 27 23:00 1:00 S
Rule Spain 1976 1977 - Sep lastSun 1:00 0 -
Rule Spain 1977 only - Apr 2 23:00 1:00 S
Rule Spain 1978 only - Apr 2 2:00s 1:00 S
Rule Spain 1978 only - Oct 1 2:00s 0 -
# Nationalist Spain during the civil war
#Rule NatSpain 1937 only - May 22 23:00 1:00 S
#Rule NatSpain 1937 1938 - Oct Sat>=1 24:00s 0 -
#Rule NatSpain 1938 only - Mar 26 23:00 1:00 S
# The following rules are copied from Morocco from 1967 through 1978,
# except with "S" letters.
Rule SpainAfrica 1967 only - Jun 3 12:00 1:00 S
Rule SpainAfrica 1967 only - Oct 1 0:00 0 -
Rule SpainAfrica 1974 only - Jun 24 0:00 1:00 S
Rule SpainAfrica 1974 only - Sep 1 0:00 0 -
Rule SpainAfrica 1976 1977 - May 1 0:00 1:00 S
Rule SpainAfrica 1976 only - Aug 1 0:00 0 -
Rule SpainAfrica 1977 only - Sep 28 0:00 0 -
Rule SpainAfrica 1978 only - Jun 1 0:00 1:00 S
Rule SpainAfrica 1978 only - Aug 4 0:00 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Madrid -0:14:44 - LMT 1900 Dec 31 23:45:16
0:00 Spain WE%sT 1940 Mar 16 23:00
1:00 Spain CE%sT 1979
1:00 EU CE%sT
Zone Africa/Ceuta -0:21:16 - LMT 1900 Dec 31 23:38:44
0:00 - WET 1918 May 6 23:00
0:00 1:00 WEST 1918 Oct 7 23:00
0:00 - WET 1924
0:00 Spain WE%sT 1929
0:00 - WET 1967 # Help zishrink.awk.
0:00 SpainAfrica WE%sT 1984 Mar 16
1:00 - CET 1986
1:00 EU CE%sT
Zone Atlantic/Canary -1:01:36 - LMT 1922 Mar # Las Palmas de Gran C.
-1:00 - -01 1946 Sep 30 1:00
0:00 - WET 1980 Apr 6 0:00s
0:00 1:00 WEST 1980 Sep 28 1:00u
0:00 EU WE%sT
# IATA SSIM (1996-09) says the Canaries switch at 2:00u, not 1:00u.
# Ignore this for now, as the Canaries are part of the EU.
# Sweden
# From Ivan Nilsson (2001-04-13), superseding Shanks & Pottenger:
#
# The law "Svensk författningssamling 1878, no 14" about standard time in 1879:
# From the beginning of 1879 (that is 01-01 00:00) the time for all
# places in the country is "the mean solar time for the meridian at
# three degrees, or twelve minutes of time, to the west of the
# meridian of the Observatory of Stockholm". The law is dated 1878-05-31.
#
# The observatory at that time had the meridian 18° 03' 30"
# eastern longitude = 01:12:14 in time. Less 12 minutes gives the
# national standard time as 01:00:14 ahead of GMT....
#
# About the beginning of CET in Sweden. The lawtext ("Svensk
# författningssamling 1899, no 44") states, that "from the beginning
# of 1900... ... the same as the mean solar time for the meridian at
# the distance of one hour of time from the meridian of the English
# observatory at Greenwich, or at 12 minutes 14 seconds to the west
# from the meridian of the Observatory of Stockholm". The law is dated
# 1899-06-16. In short: At 1900-01-01 00:00:00 the new standard time
# in Sweden is 01:00:00 ahead of GMT.
#
# 1916: The lawtext ("Svensk författningssamling 1916, no 124") states
# that "1916-05-15 is considered to begin one hour earlier". It is
# pretty obvious that at 05-14 23:00 the clocks are set to 05-15 00:00....
# Further the law says, that "1916-09-30 is considered to end one hour later".
#
# The laws regulating [DST] are available on the site of the Swedish
# Parliament beginning with 1985 - the laws regulating 1980/1984 are
# not available on the site (to my knowledge they are only available
# in Swedish): <http://www.riksdagen.se/english/work/sfst.asp> (type
# "sommartid" without the quotes in the field "Fritext" and then click
# the Sök-button).
#
# (2001-05-13):
#
# I have now found a newspaper stating that at 1916-10-01 01:00
# summertime the church-clocks etc were set back one hour to show
# 1916-10-01 00:00 standard time. The article also reports that some
# people thought the switch to standard time would take place already
# at 1916-10-01 00:00 summer time, but they had to wait for another
# hour before the event took place.
#
# Source: The newspaper "Dagens Nyheter", 1916-10-01, page 7 upper left.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Stockholm 1:12:12 - LMT 1879 Jan 1
1:00:14 - SET 1900 Jan 1 # Swedish Time
1:00 - CET 1916 May 14 23:00
1:00 1:00 CEST 1916 Oct 1 1:00
1:00 - CET 1980
1:00 EU CE%sT
# Switzerland
# From Howse:
# By the end of the 18th century clocks and watches became commonplace
# and their performance improved enormously. Communities began to keep
# mean time in preference to apparent time - Geneva from 1780 ....
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
# From Whitman (who writes "Midnight?"):
# Rule Swiss 1940 only - Nov 2 0:00 1:00 S
# Rule Swiss 1940 only - Dec 31 0:00 0 -
# From Shanks & Pottenger:
# Rule Swiss 1941 1942 - May Sun>=1 2:00 1:00 S
# Rule Swiss 1941 1942 - Oct Sun>=1 0:00 0 -
# From Alois Treindl (2008-12-17):
# I have researched the DST usage in Switzerland during the 1940ies.
#
# As I wrote in an earlier message, I suspected the current tzdata values
# to be wrong. This is now verified.
#
# I have found copies of the original ruling by the Swiss Federal
# government, in 'Eidgenössische Gesetzessammlung 1941 and 1942' (Swiss
# federal law collection)...
#
# DST began on Monday 5 May 1941, 1:00 am by shifting the clocks to 2:00 am
# DST ended on Monday 6 Oct 1941, 2:00 am by shifting the clocks to 1:00 am.
#
# DST began on Monday, 4 May 1942 at 01:00 am
# DST ended on Monday, 5 Oct 1942 at 02:00 am
#
# There was no DST in 1940, I have checked the law collection carefully.
# It is also indicated by the fact that the 1942 entry in the law
# collection points back to 1941 as a reference, but no reference to any
# other years are made.
#
# Newspaper articles I have read in the archives on 6 May 1941 reported
# about the introduction of DST (Sommerzeit in German) during the previous
# night as an absolute novelty, because this was the first time that such
# a thing had happened in Switzerland.
#
# I have also checked 1916, because one book source (Gabriel, Traité de
# l'heure dans le monde) claims that Switzerland had DST in 1916. This is
# false, no official document could be found. Probably Gabriel got misled
# by references to Germany, which introduced DST in 1916 for the first time.
#
# The tzdata rules for Switzerland must be changed to:
# Rule Swiss 1941 1942 - May Mon>=1 1:00 1:00 S
# Rule Swiss 1941 1942 - Oct Mon>=1 2:00 0 -
#
# The 1940 rules must be deleted.
#
# One further detail for Switzerland, which is probably out of scope for
# most users of tzdata: The [Europe/Zurich zone] ...
# describes all of Switzerland correctly, with the exception of
# the Canton de Genève (Geneva, Genf). Between 1848 and 1894 Geneva did not
# follow Bern Mean Time but kept its own local mean time.
# To represent this, an extra zone would be needed.
#
# From Alois Treindl (2013-09-11):
# The Federal regulations say
# https://www.admin.ch/opc/de/classified-compilation/20071096/index.html
# ... the meridian for Bern mean time ... is 7° 26' 22.50".
# Expressed in time, it is 0h29m45.5s.
# From Pierre-Yves Berger (2013-09-11):
# the "Circulaire du conseil fédéral" (December 11 1893)
# http://www.amtsdruckschriften.bar.admin.ch/viewOrigDoc.do?id=10071353
# clearly states that the [1894-06-01] change should be done at midnight
# but if no one is present after 11 at night, could be postponed until one
# hour before the beginning of service.
# From Paul Eggert (2013-09-11):
# Round BMT to the nearest even second, 0:29:46.
#
# We can find no reliable source for Shanks's assertion that all of Switzerland
# except Geneva switched to Bern Mean Time at 00:00 on 1848-09-12. This book:
#
# Jakob Messerli. Gleichmässig, pünktlich, schnell. Zeiteinteilung und
# Zeitgebrauch in der Schweiz im 19. Jahrhundert. Chronos, Zurich 1995,
# ISBN 3-905311-68-2, OCLC 717570797.
#
# suggests that the transition was more gradual, and that the Swiss did not
# agree about civil time during the transition. The timekeeping it gives the
# most detail for is postal and telegraph time: here, federal legislation (the
# "Bundesgesetz über die Erstellung von elektrischen Telegraphen") passed on
# 1851-11-23, and an official implementation notice was published 1853-07-16
# (Bundesblatt 1853, Bd. II, S. 859). On p 72 Messerli writes that in
# practice since July 1853 Bernese time was used in "all postal and telegraph
# offices in Switzerland from Geneva to St. Gallen and Basel to Chiasso"
# (Google translation). For now, model this transition as occurring on
# 1853-07-16, though it probably occurred at some other date in Zurich, and
# legal civil time probably changed at still some other transition date.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Swiss 1941 1942 - May Mon>=1 1:00 1:00 S
Rule Swiss 1941 1942 - Oct Mon>=1 2:00 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Zurich 0:34:08 - LMT 1853 Jul 16 # See above comment.
0:29:46 - BMT 1894 Jun # Bern Mean Time
1:00 Swiss CE%sT 1981
1:00 EU CE%sT
# Turkey
+# From Alois Treindl (2019-08-12):
+# http://www.astrolojidergisi.com/yazsaati.htm has researched the time zone
+# history of Turkey, based on newspaper archives and official documents.
+# From Paul Eggert (2019-08-28):
+# That source (Oya Vulaş, "Türkiye'de Yaz Saati Uygulamaları")
+# is used for 1940/1972, where it seems more reliable than our other
+# sources.
+
+# From Kıvanç Yazan (2019-08-12):
+# http://www.resmigazete.gov.tr/arsiv/14539.pdf#page=24
+# 1973-06-03 01:00 -> 02:00, 1973-11-04 02:00 -> 01:00
+#
+# http://www.resmigazete.gov.tr/arsiv/14829.pdf#page=1
+# 1974-03-31 02:00 -> 03:00, 1974-11-03 02:00 -> 01:00
+#
+# http://www.resmigazete.gov.tr/arsiv/15161.pdf#page=1
+# 1975-03-22 02:00 -> 03:00, 1975-11-02 02:00 -> 01:00
+#
+# http://www.resmigazete.gov.tr/arsiv/15535_1.pdf#page=1
+# 1976-03-21 02:00 -> 03:00, 1976-10-31 02:00 -> 01:00
+#
+# http://www.resmigazete.gov.tr/arsiv/15778.pdf#page=5
+# 1977-04-03 02:00 -> 03:00, 1977-10-16 02:00 -> 01:00,
+# 1978-04-02 02:00 -> 03:00 (not applied, see below)
+# 1978-10-15 02:00 -> 01:00 (not applied, see below)
+# 1979-04-01 02:00 -> 03:00 (not applied, see below)
+# 1979-10-14 02:00 -> 01:00 (not applied, see below)
+#
+# http://www.resmigazete.gov.tr/arsiv/16245.pdf#page=17
+# This cancels the previous decision, and repeats it only for 1978.
+# 1978-04-02 02:00 -> 03:00, 1978-10-15 02:00 -> 01:00
+# (not applied due to standard TZ change below)
+#
+# http://www.resmigazete.gov.tr/arsiv/16331.pdf#page=3
+# This decision changes the default longitude for Turkish time zone from 30
+# degrees East to 45 degrees East. This means a standard TZ change, from +2
+# to +3. This is published & applied on 1978-06-29. At that time, Turkey was
+# already on summer time (already on 45E). Hence, this new law just meant an
+# "continuous summer time". Note that this was reversed in a few years.
+#
+# http://www.resmigazete.gov.tr/arsiv/18119_1.pdf#page=1
+# 1983-07-31 02:00 -> 03:00 (note that this jumps TZ to +4)
+# 1983-10-02 02:00 -> 01:00 (back to +3)
+#
+# http://www.resmigazete.gov.tr/arsiv/18561.pdf (page 1 and 34)
+# At this time, Turkey is still on +3 with no spring-forward on early
+# 1984. This decision is published on 10/31/1984. Page 1 declares
+# the decision of reverting the "default longitude change". So the
+# standard time should go back to +3 (30E). And page 34 explains when
+# that will happen: 1984-11-01 02:00 -> 01:00. You can think of this
+# as "end of continuous summer time, change of standard time zone".
+#
+# http://www.resmigazete.gov.tr/arsiv/18713.pdf#page=1
+# 1985-04-20 01:00 -> 02:00, 1985-09-28 02:00 -> 01:00
+
# From Kıvanç Yazan (2016-09-25):
# 1) For 1986-2006, DST started at 01:00 local and ended at 02:00 local, with
# no exceptions.
# 2) 1994's lastSun was overridden with Mar 20 ...
# Here are official papers:
-# http://www.resmigazete.gov.tr/arsiv/19032.pdf - page 2 for 1986
-# http://www.resmigazete.gov.tr/arsiv/19400.pdf - page 4 for 1987
-# http://www.resmigazete.gov.tr/arsiv/19752.pdf - page 15 for 1988
-# http://www.resmigazete.gov.tr/arsiv/20102.pdf - page 6 for 1989
-# http://www.resmigazete.gov.tr/arsiv/20464.pdf - page 1 for 1990 - 1992
-# http://www.resmigazete.gov.tr/arsiv/21531.pdf - page 15 for 1993 - 1995
-# http://www.resmigazete.gov.tr/arsiv/21879.pdf - page 1 for overriding 1994
-# http://www.resmigazete.gov.tr/arsiv/22588.pdf - page 1 for 1996, 1997
-# http://www.resmigazete.gov.tr/arsiv/23286.pdf - page 10 for 1998 - 2000
+# http://www.resmigazete.gov.tr/arsiv/19032.pdf#page=2 for 1986
+# http://www.resmigazete.gov.tr/arsiv/19400.pdf#page=4 for 1987
+# http://www.resmigazete.gov.tr/arsiv/19752.pdf#page=15 for 1988
+# http://www.resmigazete.gov.tr/arsiv/20102.pdf#page=6 for 1989
+# http://www.resmigazete.gov.tr/arsiv/20464.pdf#page=1 for 1990 - 1992
+# http://www.resmigazete.gov.tr/arsiv/21531.pdf#page=15 for 1993 - 1995
+# http://www.resmigazete.gov.tr/arsiv/21879.pdf#page=1 for overriding 1994
+# http://www.resmigazete.gov.tr/arsiv/22588.pdf#page=1 for 1996, 1997
+# http://www.resmigazete.gov.tr/arsiv/23286.pdf#page=10 for 1998 - 2000
# http://www.resmigazete.gov.tr/eskiler/2001/03/20010324.htm#2 - for 2001
# http://www.resmigazete.gov.tr/eskiler/2002/03/20020316.htm#2 - for 2002-2006
# From Paul Eggert (2016-09-25):
# Prefer the above sources to Shanks & Pottenger for timestamps after 1985.
# From Steffen Thorsen (2007-03-09):
# Starting 2007 though, it seems that they are adopting EU's 1:00 UTC
# start/end time, according to the following page (2007-03-07):
# http://www.ntvmsnbc.com/news/402029.asp
# The official document is located here - it is in Turkish...:
# http://rega.basbakanlik.gov.tr/eskiler/2007/03/20070307-7.htm
# I was able to locate the following seemingly official document
# (on a non-government server though) describing dates between 2002 and 2006:
# http://www.alomaliye.com/bkk_2002_3769.htm
# From Gökdeniz Karadağ (2011-03-10):
# According to the articles linked below, Turkey will change into summer
# time zone (GMT+3) on March 28, 2011 at 3:00 a.m. instead of March 27.
# This change is due to a nationwide exam on 27th.
# https://www.worldbulletin.net/?aType=haber&ArticleID=70872
# Turkish:
# https://www.hurriyet.com.tr/yaz-saati-uygulamasi-bir-gun-ileri-alindi-17230464
# From Faruk Pasin (2014-02-14):
# The DST for Turkey has been changed for this year because of the
# Turkish Local election....
# http://www.sabah.com.tr/Ekonomi/2014/02/12/yaz-saatinde-onemli-degisiklik
# ... so Turkey will move clocks forward one hour on March 31 at 3:00 a.m.
# From Randal L. Schwartz (2014-04-15):
# Having landed on a flight from the states to Istanbul (via AMS) on March 31,
# I can tell you that NOBODY (even the airlines) respected this timezone DST
# change delay. Maybe the word just didn't get out in time.
# From Paul Eggert (2014-06-15):
# The press reported massive confusion, as election officials obeyed the rule
# change but cell phones (and airline baggage systems) did not. See:
# Kostidis M. Eventful elections in Turkey. Balkan News Agency
# http://www.balkaneu.com/eventful-elections-turkey/ 2014-03-30.
# I guess the best we can do is document the official time.
# From Fatih (2015-09-29):
# It's officially announced now by the Ministry of Energy.
# Turkey delays winter time to 8th of November 04:00
# http://www.aa.com.tr/tr/turkiye/yaz-saati-uygulamasi-8-kasimda-sona-erecek/362217
#
# From BBC News (2015-10-25):
# Confused Turks are asking "what's the time?" after automatic clocks defied a
# government decision ... "For the next two weeks #Turkey is on EEST... Erdogan
# Engineered Standard Time," said Twitter user @aysekarahasan.
# http://www.bbc.com/news/world-europe-34631326
# From Burak AYDIN (2016-09-08):
# Turkey will stay in Daylight Saving Time even in winter....
# http://www.resmigazete.gov.tr/eskiler/2016/09/20160908-2.pdf
#
# From Paul Eggert (2016-09-07):
# The change is permanent, so this is the new standard time in Turkey.
# It takes effect today, which is not much notice.
# From Kıvanç Yazan (2017-10-28):
# Turkey will go back to Daylight Saving Time starting 2018-10.
# http://www.resmigazete.gov.tr/eskiler/2017/10/20171028-5.pdf
#
# From Even Scharning (2017-11-08):
# ... today it was announced that the DST will become "continuous":
# http://www.hurriyet.com.tr/son-dakika-yaz-saati-uygulamasi-surekli-hale-geldi-40637482
# From Paul Eggert (2017-11-08):
# Although Google Translate misfires on that source, it looks like
# Turkey reversed last month's decision, and so will stay at +03.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Turkey 1916 only - May 1 0:00 1:00 S
Rule Turkey 1916 only - Oct 1 0:00 0 -
Rule Turkey 1920 only - Mar 28 0:00 1:00 S
Rule Turkey 1920 only - Oct 25 0:00 0 -
Rule Turkey 1921 only - Apr 3 0:00 1:00 S
Rule Turkey 1921 only - Oct 3 0:00 0 -
Rule Turkey 1922 only - Mar 26 0:00 1:00 S
Rule Turkey 1922 only - Oct 8 0:00 0 -
# Whitman gives 1923 Apr 28 - Sep 16 and no DST in 1924-1925;
# go with Shanks & Pottenger.
Rule Turkey 1924 only - May 13 0:00 1:00 S
Rule Turkey 1924 1925 - Oct 1 0:00 0 -
Rule Turkey 1925 only - May 1 0:00 1:00 S
-Rule Turkey 1940 only - Jun 30 0:00 1:00 S
-Rule Turkey 1940 only - Oct 5 0:00 0 -
+Rule Turkey 1940 only - Jul 1 0:00 1:00 S
+Rule Turkey 1940 only - Oct 6 0:00 0 -
Rule Turkey 1940 only - Dec 1 0:00 1:00 S
Rule Turkey 1941 only - Sep 21 0:00 0 -
Rule Turkey 1942 only - Apr 1 0:00 1:00 S
-# Whitman omits the next two transition and gives 1945 Oct 1;
-# go with Shanks & Pottenger.
-Rule Turkey 1942 only - Nov 1 0:00 0 -
-Rule Turkey 1945 only - Apr 2 0:00 1:00 S
Rule Turkey 1945 only - Oct 8 0:00 0 -
Rule Turkey 1946 only - Jun 1 0:00 1:00 S
Rule Turkey 1946 only - Oct 1 0:00 0 -
Rule Turkey 1947 1948 - Apr Sun>=16 0:00 1:00 S
-Rule Turkey 1947 1950 - Oct Sun>=2 0:00 0 -
+Rule Turkey 1947 1951 - Oct Sun>=2 0:00 0 -
Rule Turkey 1949 only - Apr 10 0:00 1:00 S
-Rule Turkey 1950 only - Apr 19 0:00 1:00 S
+Rule Turkey 1950 only - Apr 16 0:00 1:00 S
Rule Turkey 1951 only - Apr 22 0:00 1:00 S
-Rule Turkey 1951 only - Oct 8 0:00 0 -
+# DST for 15 months; unusual but we'll let it pass.
Rule Turkey 1962 only - Jul 15 0:00 1:00 S
-Rule Turkey 1962 only - Oct 8 0:00 0 -
+Rule Turkey 1963 only - Oct 30 0:00 0 -
Rule Turkey 1964 only - May 15 0:00 1:00 S
Rule Turkey 1964 only - Oct 1 0:00 0 -
-Rule Turkey 1970 1972 - May Sun>=2 0:00 1:00 S
-Rule Turkey 1970 1972 - Oct Sun>=2 0:00 0 -
Rule Turkey 1973 only - Jun 3 1:00 1:00 S
-Rule Turkey 1973 only - Nov 4 3:00 0 -
+Rule Turkey 1973 1976 - Oct Sun>=31 2:00 0 -
Rule Turkey 1974 only - Mar 31 2:00 1:00 S
-Rule Turkey 1974 only - Nov 3 5:00 0 -
-Rule Turkey 1975 only - Mar 30 0:00 1:00 S
-Rule Turkey 1975 1976 - Oct lastSun 0:00 0 -
-Rule Turkey 1976 only - Jun 1 0:00 1:00 S
-Rule Turkey 1977 1978 - Apr Sun>=1 0:00 1:00 S
-Rule Turkey 1977 only - Oct 16 0:00 0 -
-Rule Turkey 1979 1980 - Apr Sun>=1 3:00 1:00 S
-Rule Turkey 1979 1982 - Oct Mon>=11 0:00 0 -
-Rule Turkey 1981 1982 - Mar lastSun 3:00 1:00 S
-Rule Turkey 1983 only - Jul 31 0:00 1:00 S
-Rule Turkey 1983 only - Oct 2 0:00 0 -
-Rule Turkey 1985 only - Apr 20 0:00 1:00 S
-Rule Turkey 1985 only - Sep 28 0:00 0 -
+Rule Turkey 1975 only - Mar 22 2:00 1:00 S
+Rule Turkey 1976 only - Mar 21 2:00 1:00 S
+Rule Turkey 1977 1978 - Apr Sun>=1 2:00 1:00 S
+Rule Turkey 1977 1978 - Oct Sun>=15 2:00 0 -
+Rule Turkey 1978 only - Jun 29 0:00 0 -
+Rule Turkey 1983 only - Jul 31 2:00 1:00 S
+Rule Turkey 1983 only - Oct 2 2:00 0 -
+Rule Turkey 1985 only - Apr 20 1:00s 1:00 S
+Rule Turkey 1985 only - Sep 28 1:00s 0 -
Rule Turkey 1986 1993 - Mar lastSun 1:00s 1:00 S
Rule Turkey 1986 1995 - Sep lastSun 1:00s 0 -
Rule Turkey 1994 only - Mar 20 1:00s 1:00 S
Rule Turkey 1995 2006 - Mar lastSun 1:00s 1:00 S
Rule Turkey 1996 2006 - Oct lastSun 1:00s 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Istanbul 1:55:52 - LMT 1880
1:56:56 - IMT 1910 Oct # Istanbul Mean Time?
- 2:00 Turkey EE%sT 1978 Oct 15
- 3:00 Turkey +03/+04 1985 Apr 20
+ 2:00 Turkey EE%sT 1978 Jun 29
+ 3:00 Turkey +03/+04 1984 Nov 1 2:00
2:00 Turkey EE%sT 2007
2:00 EU EE%sT 2011 Mar 27 1:00u
2:00 - EET 2011 Mar 28 1:00u
2:00 EU EE%sT 2014 Mar 30 1:00u
2:00 - EET 2014 Mar 31 1:00u
2:00 EU EE%sT 2015 Oct 25 1:00u
2:00 1:00 EEST 2015 Nov 8 1:00u
2:00 EU EE%sT 2016 Sep 7
3:00 - +03
Link Europe/Istanbul Asia/Istanbul # Istanbul is in both continents.
# Ukraine
#
# From Igor Karpov, who works for the Ukrainian Ministry of Justice,
# via Garrett Wollman (2003-01-27):
# BTW, I've found the official document on this matter. It's government
# regulations No. 509, May 13, 1996. In my poor translation it says:
# "Time in Ukraine is set to second timezone (Kiev time). Each last Sunday
# of March at 3am the time is changing to 4am and each last Sunday of
# October the time at 4am is changing to 3am"
# From Alexander Krivenyshev (2011-09-20):
# On September 20, 2011 the deputies of the Verkhovna Rada agreed to
# abolish the transfer clock to winter time.
#
# Bill No. 8330 of MP from the Party of Regions Oleg Nadoshi got
# approval from 266 deputies.
#
# Ukraine abolishes transfer back to the winter time (in Russian)
# http://news.mail.ru/politics/6861560/
#
# The Ukrainians will no longer change the clock (in Russian)
# http://www.segodnya.ua/news/14290482.html
#
# Deputies cancelled the winter time (in Russian)
# https://www.pravda.com.ua/rus/news/2011/09/20/6600616/
#
# From Philip Pizzey (2011-10-18):
# Today my Ukrainian colleagues have informed me that the
# Ukrainian parliament have decided that they will go to winter
# time this year after all.
#
# From Udo Schwedt (2011-10-18):
# As far as I understand, the recent change to the Ukrainian time zone
# (Europe/Kiev) to introduce permanent daylight saving time (similar
# to Russia) was reverted today:
# http://portal.rada.gov.ua/rada/control/en/publish/article/info_left?art_id=287324&cat_id=105995
#
# Also reported by Alexander Bokovoy (2011-10-18) who also noted:
# The law documents themselves are at
# http://w1.c1.rada.gov.ua/pls/zweb_n/webproc4_1?id=&pf3511=41484
# From Vladimir in Moscow via Alois Treindl re Kiev time 1991/2 (2014-02-28):
# First in Ukraine they changed Time zone from UTC+3 to UTC+2 with DST:
# 03 25 1990 02:00 -03.00 1 Time Zone 3 with DST
# 07 01 1990 02:00 -02.00 1 Time Zone 2 with DST
# * Ukrainian Government's Resolution of 18.06.1990, No. 134.
# http://search.ligazakon.ua/l_doc2.nsf/link1/T001500.html
#
# They did not end DST in September, 1990 (according to the law,
# "summer time" was still in action):
# 09 30 1990 03:00 -02.00 1 Time Zone 2 with DST
# * Ukrainian Government's Resolution of 21.09.1990, No. 272.
# http://search.ligazakon.ua/l_doc2.nsf/link1/KP900272.html
#
# Again no change in March, 1991 ("summer time" in action):
# 03 31 1991 02:00 -02.00 1 Time Zone 2 with DST
#
# DST ended in September 1991 ("summer time" ended):
# 09 29 1991 03:00 -02.00 0 Time Zone 2, no DST
# * Ukrainian Government's Resolution of 25.09.1991, No. 225.
# http://www.uazakon.com/documents/date_21/pg_iwgdoc.htm
# This is an answer.
#
# Since 1992 they had normal DST procedure:
# 03 29 1992 02:00 -02.00 1 DST started
# 09 27 1992 03:00 -02.00 0 DST ended
# * Ukrainian Government's Resolution of 20.03.1992, No. 139.
# http://www.uazakon.com/documents/date_8u/pg_grcasa.htm
# From Paul Eggert (2018-10-03):
# As is usual in tzdb, Ukrainian zones use the most common English spellings.
# For example, tzdb uses Europe/Kiev, as "Kiev" is the most common spelling in
# English for Ukraine's capital, even though it is certainly wrong as a
# transliteration of the Ukrainian "Київ". This is similar to tzdb's use of
# Europe/Prague, which is certainly wrong as a transliteration of the Czech
# "Praha". ("Kiev" came from old Slavic via Russian to English, and "Prague"
# came from old Slavic via French to English, so the two cases have something
# in common.) Admittedly English-language spelling of Ukrainian names is
# controversial, and some day "Kyiv" may become substantially more popular in
# English; in the meantime, stick with the traditional English "Kiev" as that
# means less disruption for our users.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
# This represents most of Ukraine. See above for the spelling of "Kiev".
Zone Europe/Kiev 2:02:04 - LMT 1880
2:02:04 - KMT 1924 May 2 # Kiev Mean Time
2:00 - EET 1930 Jun 21
3:00 - MSK 1941 Sep 20
1:00 C-Eur CE%sT 1943 Nov 6
3:00 Russia MSK/MSD 1990 Jul 1 2:00
2:00 1:00 EEST 1991 Sep 29 3:00
2:00 E-Eur EE%sT 1995
2:00 EU EE%sT
# Ruthenia used CET 1990/1991.
# "Uzhhorod" is the transliteration of the Rusyn/Ukrainian pronunciation, but
# "Uzhgorod" is more common in English.
Zone Europe/Uzhgorod 1:29:12 - LMT 1890 Oct
1:00 - CET 1940
1:00 C-Eur CE%sT 1944 Oct
1:00 1:00 CEST 1944 Oct 26
1:00 - CET 1945 Jun 29
3:00 Russia MSK/MSD 1990
3:00 - MSK 1990 Jul 1 2:00
1:00 - CET 1991 Mar 31 3:00
2:00 - EET 1992
2:00 E-Eur EE%sT 1995
2:00 EU EE%sT
# Zaporozh'ye and eastern Lugansk oblasts observed DST 1990/1991.
# "Zaporizhia" is the transliteration of the Ukrainian name, but
# "Zaporozh'ye" is more common in English. Use the common English
# spelling, except omit the apostrophe as it is not allowed in
# portable Posix file names.
Zone Europe/Zaporozhye 2:20:40 - LMT 1880
2:20 - +0220 1924 May 2
2:00 - EET 1930 Jun 21
3:00 - MSK 1941 Aug 25
1:00 C-Eur CE%sT 1943 Oct 25
3:00 Russia MSK/MSD 1991 Mar 31 2:00
2:00 E-Eur EE%sT 1995
2:00 EU EE%sT
# Vatican City
# See Europe/Rome.
###############################################################################
# One source shows that Bulgaria, Cyprus, Finland, and Greece observe DST from
# the last Sunday in March to the last Sunday in September in 1986.
# The source shows Romania changing a day later than everybody else.
#
# According to Bernard Sieloff's source, Poland is in the MET time zone but
# uses the WE DST rules. The Western USSR uses EET+1 and ME DST rules.
# Bernard Sieloff's source claims Romania switches on the same day, but at
# 00:00 standard time (i.e., 01:00 DST). It also claims that Turkey
# switches on the same day, but switches on at 01:00 standard time
# and off at 00:00 standard time (i.e., 01:00 DST)
# ...
# Date: Wed, 28 Jan 87 16:56:27 -0100
# From: Tom Hofmann
# ...
#
# ...the European time rules are...standardized since 1981, when
# most European countries started DST. Before that year, only
# a few countries (UK, France, Italy) had DST, each according
# to own national rules. In 1981, however, DST started on
# 'Apr firstSun', and not on 'Mar lastSun' as in the following
# years...
# But also since 1981 there are some more national exceptions
# than listed in 'europe': Switzerland, for example, joined DST
# one year later, Denmark ended DST on 'Oct 1' instead of 'Sep
# lastSun' in 1981 - I don't know how they handle now.
#
# Finally, DST ist always from 'Apr 1' to 'Oct 1' in the
# Soviet Union (as far as I know).
#
# Tom Hofmann, Scientific Computer Center, CIBA-GEIGY AG,
# 4002 Basle, Switzerland
# ...
# ...
# Date: Wed, 4 Feb 87 22:35:22 +0100
# From: Dik T. Winter
# ...
#
# The information from Tom Hofmann is (as far as I know) not entirely correct.
# After a request from chongo at amdahl I tried to retrieve all information
# about DST in Europe. I was able to find all from about 1969.
#
# ...standardization on DST in Europe started in about 1977 with switches on
# first Sunday in April and last Sunday in September...
# In 1981 UK joined Europe insofar that
# the starting day for both shifted to last Sunday in March. And from 1982
# the whole of Europe used DST, with switch dates April 1 and October 1 in
# the Sov[i]et Union. In 1985 the SU reverted to standard Europe[a]n switch
# dates...
#
# It should also be remembered that time-zones are not constants; e.g.
# Portugal switched in 1976 from MET (or CET) to WET with DST...
# Note also that though there were rules for switch dates not
# all countries abided to these dates, and many individual deviations
# occurred, though not since 1982 I believe. Another note: it is always
# assumed that DST is 1 hour ahead of normal time, this need not be the
# case; at least in the Netherlands there have been times when DST was 2 hours
# in advance of normal time.
#
# ...
# dik t. winter, cwi, amsterdam, nederland
# ...
# From Bob Devine (1988-01-28):
# ...
# Greece: Last Sunday in April to last Sunday in September (iffy on dates).
# Since 1978. Change at midnight.
# ...
# Monaco: has same DST as France.
# ...
Index: stable/12/contrib/tzdata/leap-seconds.list
===================================================================
--- stable/12/contrib/tzdata/leap-seconds.list (revision 352352)
+++ stable/12/contrib/tzdata/leap-seconds.list (revision 352353)
@@ -1,255 +1,255 @@
#
# In the following text, the symbol '#' introduces
# a comment, which continues from that symbol until
# the end of the line. A plain comment line has a
# whitespace character following the comment indicator.
# There are also special comment lines defined below.
# A special comment will always have a non-whitespace
# character in column 2.
#
# A blank line should be ignored.
#
# The following table shows the corrections that must
# be applied to compute International Atomic Time (TAI)
# from the Coordinated Universal Time (UTC) values that
# are transmitted by almost all time services.
#
# The first column shows an epoch as a number of seconds
# since 1 January 1900, 00:00:00 (1900.0 is also used to
# indicate the same epoch.) Both of these time stamp formats
# ignore the complexities of the time scales that were
# used before the current definition of UTC at the start
# of 1972. (See note 3 below.)
# The second column shows the number of seconds that
# must be added to UTC to compute TAI for any timestamp
# at or after that epoch. The value on each line is
# valid from the indicated initial instant until the
# epoch given on the next one or indefinitely into the
# future if there is no next line.
# (The comment on each line shows the representation of
# the corresponding initial epoch in the usual
# day-month-year format. The epoch always begins at
# 00:00:00 UTC on the indicated day. See Note 5 below.)
#
# Important notes:
#
# 1. Coordinated Universal Time (UTC) is often referred to
# as Greenwich Mean Time (GMT). The GMT time scale is no
# longer used, and the use of GMT to designate UTC is
# discouraged.
#
# 2. The UTC time scale is realized by many national
# laboratories and timing centers. Each laboratory
# identifies its realization with its name: Thus
# UTC(NIST), UTC(USNO), etc. The differences among
# these different realizations are typically on the
# order of a few nanoseconds (i.e., 0.000 000 00x s)
# and can be ignored for many purposes. These differences
# are tabulated in Circular T, which is published monthly
# by the International Bureau of Weights and Measures
# (BIPM). See www.bipm.org for more information.
#
# 3. The current definition of the relationship between UTC
# and TAI dates from 1 January 1972. A number of different
# time scales were in use before that epoch, and it can be
# quite difficult to compute precise timestamps and time
# intervals in those "prehistoric" days. For more information,
# consult:
#
# The Explanatory Supplement to the Astronomical
# Ephemeris.
# or
# Terry Quinn, "The BIPM and the Accurate Measurement
# of Time," Proc. of the IEEE, Vol. 79, pp. 894-905,
# July, 1991. <http://dx.doi.org/10.1109/5.84965>
# reprinted in:
# Christine Hackman and Donald B Sullivan (eds.)
# Time and Frequency Measurement
# American Association of Physics Teachers (1996)
# <http://tf.nist.gov/general/pdf/1168.pdf>, pp. 75-86
#
# 4. The decision to insert a leap second into UTC is currently
# the responsibility of the International Earth Rotation and
# Reference Systems Service. (The name was changed from the
# International Earth Rotation Service, but the acronym IERS
# is still used.)
#
# Leap seconds are announced by the IERS in its Bulletin C.
#
# See www.iers.org for more details.
#
# Every national laboratory and timing center uses the
# data from the BIPM and the IERS to construct UTC(lab),
# their local realization of UTC.
#
# Although the definition also includes the possibility
# of dropping seconds ("negative" leap seconds), this has
# never been done and is unlikely to be necessary in the
# foreseeable future.
#
# 5. If your system keeps time as the number of seconds since
# some epoch (e.g., NTP timestamps), then the algorithm for
# assigning a UTC time stamp to an event that happens during a positive
# leap second is not well defined. The official name of that leap
# second is 23:59:60, but there is no way of representing that time
# in these systems.
# Many systems of this type effectively stop the system clock for
# one second during the leap second and use a time that is equivalent
# to 23:59:59 UTC twice. For these systems, the corresponding TAI
# timestamp would be obtained by advancing to the next entry in the
# following table when the time equivalent to 23:59:59 UTC
# is used for the second time. Thus the leap second which
# occurred on 30 June 1972 at 23:59:59 UTC would have TAI
# timestamps computed as follows:
#
# ...
# 30 June 1972 23:59:59 (2287785599, first time): TAI= UTC + 10 seconds
# 30 June 1972 23:59:60 (2287785599,second time): TAI= UTC + 11 seconds
# 1 July 1972 00:00:00 (2287785600) TAI= UTC + 11 seconds
# ...
#
# If your system realizes the leap second by repeating 00:00:00 UTC twice
# (this is possible but not usual), then the advance to the next entry
# in the table must occur the second time that a time equivalent to
# 00:00:00 UTC is used. Thus, using the same example as above:
#
# ...
# 30 June 1972 23:59:59 (2287785599): TAI= UTC + 10 seconds
# 30 June 1972 23:59:60 (2287785600, first time): TAI= UTC + 10 seconds
# 1 July 1972 00:00:00 (2287785600,second time): TAI= UTC + 11 seconds
# ...
#
# in both cases the use of timestamps based on TAI produces a smooth
# time scale with no discontinuity in the time interval. However,
# although the long-term behavior of the time scale is correct in both
# methods, the second method is technically not correct because it adds
# the extra second to the wrong day.
#
# This complexity would not be needed for negative leap seconds (if they
# are ever used). The UTC time would skip 23:59:59 and advance from
# 23:59:58 to 00:00:00 in that case. The TAI offset would decrease by
# 1 second at the same instant. This is a much easier situation to deal
# with, since the difficulty of unambiguously representing the epoch
# during the leap second does not arise.
#
# Some systems implement leap seconds by amortizing the leap second
# over the last few minutes of the day. The frequency of the local
# clock is decreased (or increased) to realize the positive (or
# negative) leap second. This method removes the time step described
# above. Although the long-term behavior of the time scale is correct
# in this case, this method introduces an error during the adjustment
# period both in time and in frequency with respect to the official
# definition of UTC.
#
# Questions or comments to:
# Judah Levine
# Time and Frequency Division
# NIST
# Boulder, Colorado
# Judah.Levine@nist.gov
#
# Last Update of leap second values: 8 July 2016
#
# The following line shows this last update date in NTP timestamp
# format. This is the date on which the most recent change to
# the leap second data was added to the file. This line can
# be identified by the unique pair of characters in the first two
# columns as shown below.
#
#$ 3676924800
#
# The NTP timestamps are in units of seconds since the NTP epoch,
# which is 1 January 1900, 00:00:00. The Modified Julian Day number
# corresponding to the NTP time stamp, X, can be computed as
#
# X/86400 + 15020
#
# where the first term converts seconds to days and the second
# term adds the MJD corresponding to the time origin defined above.
# The integer portion of the result is the integer MJD for that
# day, and any remainder is the time of day, expressed as the
# fraction of the day since 0 hours UTC. The conversion from day
# fraction to seconds or to hours, minutes, and seconds may involve
# rounding or truncation, depending on the method used in the
# computation.
#
# The data in this file will be updated periodically as new leap
# seconds are announced. In addition to being entered on the line
# above, the update time (in NTP format) will be added to the basic
# file name leap-seconds to form the name leap-seconds.<NTP TIME>.
# In addition, the generic name leap-seconds.list will always point to
# the most recent version of the file.
#
# This update procedure will be performed only when a new leap second
# is announced.
#
# The following entry specifies the expiration date of the data
# in this file in units of seconds since the origin at the instant
# 1 January 1900, 00:00:00. This expiration date will be changed
# at least twice per year whether or not a new leap second is
# announced. These semi-annual changes will be made no later
# than 1 June and 1 December of each year to indicate what
# action (if any) is to be taken on 30 June and 31 December,
# respectively. (These are the customary effective dates for new
# leap seconds.) This expiration date will be identified by a
# unique pair of characters in columns 1 and 2 as shown below.
# In the unlikely event that a leap second is announced with an
# effective date other than 30 June or 31 December, then this
# file will be edited to include that leap second as soon as it is
# announced or at least one month before the effective date
# (whichever is later).
# If an announcement by the IERS specifies that no leap second is
# scheduled, then only the expiration date of the file will
# be advanced to show that the information in the file is still
# current -- the update time stamp, the data and the name of the file
# will not change.
#
-# Updated through IERS Bulletin C57
-# File expires on: 28 December 2019
+# Updated through IERS Bulletin C58
+# File expires on: 28 June 2020
#
-#@ 3786480000
+#@ 3802291200
#
2272060800 10 # 1 Jan 1972
2287785600 11 # 1 Jul 1972
2303683200 12 # 1 Jan 1973
2335219200 13 # 1 Jan 1974
2366755200 14 # 1 Jan 1975
2398291200 15 # 1 Jan 1976
2429913600 16 # 1 Jan 1977
2461449600 17 # 1 Jan 1978
2492985600 18 # 1 Jan 1979
2524521600 19 # 1 Jan 1980
2571782400 20 # 1 Jul 1981
2603318400 21 # 1 Jul 1982
2634854400 22 # 1 Jul 1983
2698012800 23 # 1 Jul 1985
2776982400 24 # 1 Jan 1988
2840140800 25 # 1 Jan 1990
2871676800 26 # 1 Jan 1991
2918937600 27 # 1 Jul 1992
2950473600 28 # 1 Jul 1993
2982009600 29 # 1 Jul 1994
3029443200 30 # 1 Jan 1996
3076704000 31 # 1 Jul 1997
3124137600 32 # 1 Jan 1999
3345062400 33 # 1 Jan 2006
3439756800 34 # 1 Jan 2009
3550089600 35 # 1 Jul 2012
3644697600 36 # 1 Jul 2015
3692217600 37 # 1 Jan 2017
#
# the following special comment contains the
# hash value of the data in this file computed
# use the secure hash algorithm as specified
# by FIPS 180-1. See the files in ~/pub/sha for
# the details of how this hash value is
# computed. Note that the hash computation
# ignores comments and whitespace characters
# in data lines. It includes the NTP values
# of both the last modification time and the
# expiration time of the file, but not the
# white space on those lines.
# the hash line is also ignored in the
# computation.
#
-#h 83c68138 d3650221 07dbbbcd 11fcc859 ced1106a
+#h f28827d2 f263b6c3 ec0f19eb a3e0dbf0 97f3fa30
Index: stable/12/contrib/tzdata/leapseconds
===================================================================
--- stable/12/contrib/tzdata/leapseconds (revision 352352)
+++ stable/12/contrib/tzdata/leapseconds (revision 352353)
@@ -1,69 +1,72 @@
# Allowance for leap seconds added to each time zone file.
# This file is in the public domain.
# This file is generated automatically from the data in the public-domain
-# leap-seconds.list file, which can be copied from
+# NIST format leap-seconds.list file, which can be copied from
# <ftp://ftp.nist.gov/pub/time/leap-seconds.list>
-# or <ftp://ftp.boulder.nist.gov/pub/time/leap-seconds.list>
-# or <ftp://tycho.usno.navy.mil/pub/ntp/leap-seconds.list>.
+# or <ftp://ftp.boulder.nist.gov/pub/time/leap-seconds.list>.
# For more about leap-seconds.list, please see
# The NTP Timescale and Leap Seconds
# <https://www.eecis.udel.edu/~mills/leap.html>.
-# The International Earth Rotation and Reference Systems Service
+# The rules for leap seconds are specified in Annex 1 (Time scales) of:
+# Standard-frequency and time-signal emissions.
+# International Telecommunication Union - Radiocommunication Sector
+# (ITU-R) Recommendation TF.460-6 (02/2002)
+# <https://www.itu.int/rec/R-REC-TF.460-6-200202-I/>.
+# The International Earth Rotation and Reference Systems Service (IERS)
# periodically uses leap seconds to keep UTC to within 0.9 s of UT1
-# (which measures the true angular orientation of the earth in space)
+# (a proxy for Earth's angle in space as measured by astronomers)
# and publishes leap second data in a copyrighted file
# <https://hpiers.obspm.fr/iers/bul/bulc/Leap_Second.dat>.
# See: Levine J. Coordinated Universal Time and the leap second.
# URSI Radio Sci Bull. 2016;89(4):30-6. doi:10.23919/URSIRSB.2016.7909995
# <https://ieeexplore.ieee.org/document/7909995>.
-# There were no leap seconds before 1972, because the official mechanism
-# accounting for the discrepancy between atomic time and the earth's rotation
-# did not exist. The first ("1 Jan 1972") data line in leap-seconds.list
+# There were no leap seconds before 1972, as no official mechanism
+# accounted for the discrepancy between atomic time (TAI) and the earth's
+# rotation. The first ("1 Jan 1972") data line in leap-seconds.list
# does not denote a leap second; it denotes the start of the current definition
# of UTC.
-# The correction (+ or -) is made at the given time, so lines
-# will typically look like:
-# Leap YEAR MON DAY 23:59:60 + R/S
-# or
-# Leap YEAR MON DAY 23:59:59 - R/S
-
-# If the leap second is Rolling (R) the given time is local time (unused here).
+# All leap-seconds are Stationary (S) at the given UTC time.
+# The correction (+ or -) is made at the given time, so in the unlikely
+# event of a negative leap second, a line would look like this:
+# Leap YEAR MON DAY 23:59:59 - S
+# Typical lines look like this:
+# Leap YEAR MON DAY 23:59:60 + S
Leap 1972 Jun 30 23:59:60 + S
Leap 1972 Dec 31 23:59:60 + S
Leap 1973 Dec 31 23:59:60 + S
Leap 1974 Dec 31 23:59:60 + S
Leap 1975 Dec 31 23:59:60 + S
Leap 1976 Dec 31 23:59:60 + S
Leap 1977 Dec 31 23:59:60 + S
Leap 1978 Dec 31 23:59:60 + S
Leap 1979 Dec 31 23:59:60 + S
Leap 1981 Jun 30 23:59:60 + S
Leap 1982 Jun 30 23:59:60 + S
Leap 1983 Jun 30 23:59:60 + S
Leap 1985 Jun 30 23:59:60 + S
Leap 1987 Dec 31 23:59:60 + S
Leap 1989 Dec 31 23:59:60 + S
Leap 1990 Dec 31 23:59:60 + S
Leap 1992 Jun 30 23:59:60 + S
Leap 1993 Jun 30 23:59:60 + S
Leap 1994 Jun 30 23:59:60 + S
Leap 1995 Dec 31 23:59:60 + S
Leap 1997 Jun 30 23:59:60 + S
Leap 1998 Dec 31 23:59:60 + S
Leap 2005 Dec 31 23:59:60 + S
Leap 2008 Dec 31 23:59:60 + S
Leap 2012 Jun 30 23:59:60 + S
Leap 2015 Jun 30 23:59:60 + S
Leap 2016 Dec 31 23:59:60 + S
# POSIX timestamps for the data in this file:
-#updated 1467936000
-#expires 1577491200
+#updated 1467936000 (2016-07-08 00:00:00 UTC)
+#expires 1593302400 (2020-06-28 00:00:00 UTC)
-# Updated through IERS Bulletin C57
-# File expires on: 28 December 2019
+# Updated through IERS Bulletin C58
+# File expires on: 28 June 2020
Index: stable/12/contrib/tzdata/leapseconds.awk
===================================================================
--- stable/12/contrib/tzdata/leapseconds.awk (revision 352352)
+++ stable/12/contrib/tzdata/leapseconds.awk (revision 352353)
@@ -1,108 +1,223 @@
-# Generate the 'leapseconds' file from 'leap-seconds.list'.
+# Generate zic format 'leapseconds' from NIST format 'leap-seconds.list'.
# This file is in the public domain.
+# This program uses awk arithmetic. POSIX requires awk to support
+# exact integer arithmetic only through 10**10, which means for NTP
+# timestamps this program works only to the year 2216, which is the
+# year 1900 plus 10**10 seconds. However, in practice
+# POSIX-conforming awk implementations invariably use IEEE-754 double
+# and so support exact integers through 2**53. By the year 2216,
+# POSIX will almost surely require at least 2**53 for awk, so for NTP
+# timestamps this program should be good until the year 285,428,681
+# (the year 1900 plus 2**53 seconds). By then leap seconds will be
+# long obsolete, as the Earth will likely slow down so much that
+# there will be more than 25 hours per day and so some other scheme
+# will be needed.
+
BEGIN {
print "# Allowance for leap seconds added to each time zone file."
print ""
print "# This file is in the public domain."
print ""
print "# This file is generated automatically from the data in the public-domain"
- print "# leap-seconds.list file, which can be copied from"
+ print "# NIST format leap-seconds.list file, which can be copied from"
print "# <ftp://ftp.nist.gov/pub/time/leap-seconds.list>"
- print "# or <ftp://ftp.boulder.nist.gov/pub/time/leap-seconds.list>"
- print "# or <ftp://tycho.usno.navy.mil/pub/ntp/leap-seconds.list>."
+ print "# or <ftp://ftp.boulder.nist.gov/pub/time/leap-seconds.list>."
print "# For more about leap-seconds.list, please see"
print "# The NTP Timescale and Leap Seconds"
print "# <https://www.eecis.udel.edu/~mills/leap.html>."
print ""
- print "# The International Earth Rotation and Reference Systems Service"
+ print "# The rules for leap seconds are specified in Annex 1 (Time scales) of:"
+ print "# Standard-frequency and time-signal emissions."
+ print "# International Telecommunication Union - Radiocommunication Sector"
+ print "# (ITU-R) Recommendation TF.460-6 (02/2002)"
+ print "# <https://www.itu.int/rec/R-REC-TF.460-6-200202-I/>."
+ print "# The International Earth Rotation and Reference Systems Service (IERS)"
print "# periodically uses leap seconds to keep UTC to within 0.9 s of UT1"
- print "# (which measures the true angular orientation of the earth in space)"
+ print "# (a proxy for Earth's angle in space as measured by astronomers)"
print "# and publishes leap second data in a copyrighted file"
print "# <https://hpiers.obspm.fr/iers/bul/bulc/Leap_Second.dat>."
print "# See: Levine J. Coordinated Universal Time and the leap second."
print "# URSI Radio Sci Bull. 2016;89(4):30-6. doi:10.23919/URSIRSB.2016.7909995"
print "# <https://ieeexplore.ieee.org/document/7909995>."
print ""
- print "# There were no leap seconds before 1972, because the official mechanism"
- print "# accounting for the discrepancy between atomic time and the earth's rotation"
- print "# did not exist. The first (\"1 Jan 1972\") data line in leap-seconds.list"
+ print "# There were no leap seconds before 1972, as no official mechanism"
+ print "# accounted for the discrepancy between atomic time (TAI) and the earth's"
+ print "# rotation. The first (\"1 Jan 1972\") data line in leap-seconds.list"
print "# does not denote a leap second; it denotes the start of the current definition"
- print"# of UTC."
+ print "# of UTC."
print ""
- print "# The correction (+ or -) is made at the given time, so lines"
- print "# will typically look like:"
- print "# Leap YEAR MON DAY 23:59:60 + R/S"
- print "# or"
- print "# Leap YEAR MON DAY 23:59:59 - R/S"
- print ""
- print "# If the leap second is Rolling (R) the given time is local time (unused here)."
+ print "# All leap-seconds are Stationary (S) at the given UTC time."
+ print "# The correction (+ or -) is made at the given time, so in the unlikely"
+ print "# event of a negative leap second, a line would look like this:"
+ print "# Leap YEAR MON DAY 23:59:59 - S"
+ print "# Typical lines look like this:"
+ print "# Leap YEAR MON DAY 23:59:60 + S"
monthabbr[ 1] = "Jan"
monthabbr[ 2] = "Feb"
monthabbr[ 3] = "Mar"
monthabbr[ 4] = "Apr"
monthabbr[ 5] = "May"
monthabbr[ 6] = "Jun"
monthabbr[ 7] = "Jul"
monthabbr[ 8] = "Aug"
monthabbr[ 9] = "Sep"
monthabbr[10] = "Oct"
monthabbr[11] = "Nov"
monthabbr[12] = "Dec"
- for (i in monthabbr) {
- monthnum[monthabbr[i]] = i
- monthlen[i] = 31
- }
- monthlen[2] = 28
- monthlen[4] = monthlen[6] = monthlen[9] = monthlen[11] = 30
+
+ # Strip trailing CR, in case the input has CRLF form a la NIST.
+ RS = "\r?\n"
+
+ sstamp_init()
}
-/^#\tUpdated through/ || /^#\tFile expires on:/ {
+/^#[ \t]*[Uu]pdated through/ || /^#[ \t]*[Ff]ile expires on/ {
last_lines = last_lines $0 "\n"
}
/^#[$][ \t]/ { updated = $2 }
/^#[@][ \t]/ { expires = $2 }
-/^#/ { next }
+/^[ \t]*#/ { next }
{
NTP_timestamp = $1
TAI_minus_UTC = $2
- hash_mark = $3
- one = $4
- month = $5
- year = $6
if (old_TAI_minus_UTC) {
if (old_TAI_minus_UTC < TAI_minus_UTC) {
sign = "23:59:60\t+"
} else {
sign = "23:59:59\t-"
}
- m = monthnum[month] - 1
- if (m == 0) {
- year--;
- m = 12
- }
- month = monthabbr[m]
- day = monthlen[m]
- day += m == 2 && year % 4 == 0 && (year % 100 != 0 || year % 400 == 0)
- printf "Leap\t%s\t%s\t%s\t%s\tS\n", year, month, day, sign
+ sstamp_to_ymdhMs(NTP_timestamp - 1, ss_NTP)
+ printf "Leap\t%d\t%s\t%d\t%s\tS\n", \
+ ss_year, monthabbr[ss_month], ss_mday, sign
}
old_TAI_minus_UTC = TAI_minus_UTC
}
END {
# The difference between the NTP and POSIX epochs is 70 years
# (including 17 leap days), each 24 hours of 60 minutes of 60
# seconds each.
epoch_minus_NTP = ((1970 - 1900) * 365 + 17) * 24 * 60 * 60
print ""
print "# POSIX timestamps for the data in this file:"
- printf "#updated %s\n", updated - epoch_minus_NTP
- printf "#expires %s\n", expires - epoch_minus_NTP
+ sstamp_to_ymdhMs(updated, ss_NTP)
+ printf "#updated %d (%.4d-%.2d-%.2d %.2d:%.2d:%.2d UTC)\n", \
+ updated - epoch_minus_NTP, \
+ ss_year, ss_month, ss_mday, ss_hour, ss_min, ss_sec
+ sstamp_to_ymdhMs(expires, ss_NTP)
+ printf "#expires %d (%.4d-%.2d-%.2d %.2d:%.2d:%.2d UTC)\n", \
+ expires - epoch_minus_NTP, \
+ ss_year, ss_month, ss_mday, ss_hour, ss_min, ss_sec
+
printf "\n%s", last_lines
+}
+
+# sstamp_to_ymdhMs - convert seconds timestamp to date and time
+#
+# Call as:
+#
+# sstamp_to_ymdhMs(sstamp, epoch_days)
+#
+# where:
+#
+# sstamp - is the seconds timestamp.
+# epoch_days - is the timestamp epoch in Gregorian days since 1600-03-01.
+# ss_NTP is appropriate for an NTP sstamp.
+#
+# Both arguments should be nonnegative integers.
+# On return, the following variables are set based on sstamp:
+#
+# ss_year - Gregorian calendar year
+# ss_month - month of the year (1-January to 12-December)
+# ss_mday - day of the month (1-31)
+# ss_hour - hour (0-23)
+# ss_min - minute (0-59)
+# ss_sec - second (0-59)
+# ss_wday - day of week (0-Sunday to 6-Saturday)
+#
+# The function sstamp_init should be called prior to using sstamp_to_ymdhMs.
+
+function sstamp_init()
+{
+ # Days in month N, where March is month 0 and January month 10.
+ ss_mon_days[ 0] = 31
+ ss_mon_days[ 1] = 30
+ ss_mon_days[ 2] = 31
+ ss_mon_days[ 3] = 30
+ ss_mon_days[ 4] = 31
+ ss_mon_days[ 5] = 31
+ ss_mon_days[ 6] = 30
+ ss_mon_days[ 7] = 31
+ ss_mon_days[ 8] = 30
+ ss_mon_days[ 9] = 31
+ ss_mon_days[10] = 31
+
+ # Counts of days in a Gregorian year, quad-year, century, and quad-century.
+ ss_year_days = 365
+ ss_quadyear_days = ss_year_days * 4 + 1
+ ss_century_days = ss_quadyear_days * 25 - 1
+ ss_quadcentury_days = ss_century_days * 4 + 1
+
+ # Standard day epochs, suitable for epoch_days.
+ # ss_MJD = 94493
+ # ss_POSIX = 135080
+ ss_NTP = 109513
+}
+
+function sstamp_to_ymdhMs(sstamp, epoch_days, \
+ quadcentury, century, quadyear, year, month, day)
+{
+ ss_hour = int(sstamp / 3600) % 24
+ ss_min = int(sstamp / 60) % 60
+ ss_sec = sstamp % 60
+
+ # Start with a count of days since 1600-03-01 Gregorian.
+ day = epoch_days + int(sstamp / (24 * 60 * 60))
+
+ # Compute a year-month-day date with days of the month numbered
+ # 0-30, months (March-February) numbered 0-11, and years that start
+ # start March 1 and end after the last day of February. A quad-year
+ # starts on March 1 of a year evenly divisible by 4 and ends after
+ # the last day of February 4 years later. A century starts on and
+ # ends before March 1 in years evenly divisible by 100.
+ # A quad-century starts on and ends before March 1 in years divisible
+ # by 400. While the number of days in a quad-century is a constant,
+ # the number of days in each other time period can vary by 1.
+ # Any variation is in the last day of the time period (there might
+ # or might not be a February 29) where it is easy to deal with.
+
+ quadcentury = int(day / ss_quadcentury_days)
+ day -= quadcentury * ss_quadcentury_days
+ ss_wday = (day + 3) % 7
+ century = int(day / ss_century_days)
+ century -= century == 4
+ day -= century * ss_century_days
+ quadyear = int(day / ss_quadyear_days)
+ day -= quadyear * ss_quadyear_days
+ year = int(day / ss_year_days)
+ year -= year == 4
+ day -= year * ss_year_days
+ for (month = 0; month < 11; month++) {
+ if (day < ss_mon_days[month])
+ break
+ day -= ss_mon_days[month]
+ }
+
+ # Convert the date to a conventional day of month (1-31),
+ # month (1-12, January-December) and Gregorian year.
+ ss_mday = day + 1
+ if (month <= 9) {
+ ss_month = month + 3
+ } else {
+ ss_month = month - 9
+ year++
+ }
+ ss_year = 1600 + quadcentury * 400 + century * 100 + quadyear * 4 + year
}
Index: stable/12/contrib/tzdata/northamerica
===================================================================
--- stable/12/contrib/tzdata/northamerica (revision 352352)
+++ stable/12/contrib/tzdata/northamerica (revision 352353)
@@ -1,3508 +1,3570 @@
# tzdb data for North and Central America and environs
# This file is in the public domain, so clarified as of
# 2009-05-17 by Arthur David Olson.
# also includes Central America and the Caribbean
# This file is by no means authoritative; if you think you know better,
# go ahead and edit the file (and please send any changes to
# tz@iana.org for general use in the future). For more, please see
# the file CONTRIBUTING in the tz distribution.
# From Paul Eggert (1999-03-22):
# A reliable and entertaining source about time zones is
# Derek Howse, Greenwich time and longitude, Philip Wilson Publishers (1997).
###############################################################################
# United States
# From Paul Eggert (1999-03-31):
# Howse writes (pp 121-125) that time zones were invented by
# Professor Charles Ferdinand Dowd (1825-1904),
# Principal of Temple Grove Ladies' Seminary (Saratoga Springs, NY).
# His pamphlet "A System of National Time for Railroads" (1870)
# was the result of his proposals at the Convention of Railroad Trunk Lines
# in New York City (1869-10). His 1870 proposal was based on Washington, DC,
# but in 1872-05 he moved the proposed origin to Greenwich.
# From Paul Eggert (2018-03-20):
# Dowd's proposal left many details unresolved, such as where to draw
# lines between time zones. The key individual who made time zones
# work in the US was William Frederick Allen - railway engineer,
# managing editor of the Travelers' Guide, and secretary of the
# General Time Convention, a railway standardization group. Allen
# spent months in dialogs with scientific and railway leaders,
# developed a workable plan to institute time zones, and presented it
# to the General Time Convention on 1883-04-11, saying that his plan
# meant "local time would be practically abolished" - a plus for
# railway scheduling. By the next convention on 1883-10-11 nearly all
# railroads had agreed and it took effect on 1883-11-18. That Sunday
# was called the "day of two noons", as some locations observed noon
# twice. Allen witnessed the transition in New York City, writing:
#
# I heard the bells of St. Paul's strike on the old time. Four
# minutes later, obedient to the electrical signal from the Naval
# Observatory ... the time-ball made its rapid descent, the chimes
# of old Trinity rang twelve measured strokes, and local time was
# abandoned, probably forever.
#
# Most of the US soon followed suit. See:
# Bartky IR. The adoption of standard time. Technol Cult 1989 Jan;30(1):25-56.
# https://dx.doi.org/10.2307/3105430
# From Paul Eggert (2005-04-16):
# That 1883 transition occurred at 12:00 new time, not at 12:00 old time.
# See p 46 of David Prerau, Seize the daylight, Thunder's Mouth Press (2005).
# From Paul Eggert (2006-03-22):
# A good source for time zone historical data in the US is
# Thomas G. Shanks, The American Atlas (5th edition),
# San Diego: ACS Publications, Inc. (1991).
# Make sure you have the errata sheet; the book is somewhat useless without it.
# It is the source for most of the pre-1991 US entries below.
# From Paul Eggert (2001-03-06):
# Daylight Saving Time was first suggested as a joke by Benjamin Franklin
# in his whimsical essay "An Economical Project for Diminishing the Cost
# of Light" published in the Journal de Paris (1784-04-26).
# Not everyone is happy with the results:
#
# I don't really care how time is reckoned so long as there is some
# agreement about it, but I object to being told that I am saving
# daylight when my reason tells me that I am doing nothing of the kind.
# I even object to the implication that I am wasting something
# valuable if I stay in bed after the sun has risen. As an admirer
# of moonlight I resent the bossy insistence of those who want to
# reduce my time for enjoying it. At the back of the Daylight Saving
# scheme I detect the bony, blue-fingered hand of Puritanism, eager
# to push people into bed earlier, and get them up earlier, to make
# them healthy, wealthy and wise in spite of themselves.
#
# -- Robertson Davies, The diary of Samuel Marchbanks,
# Clarke, Irwin (1947), XIX, Sunday
#
# For more about the first ten years of DST in the United States, see
# Robert Garland, Ten years of daylight saving from the Pittsburgh standpoint
# (Carnegie Library of Pittsburgh, 1927).
# http://www.clpgh.org/exhibit/dst.html
#
# Shanks says that DST was called "War Time" in the US in 1918 and 1919.
# However, DST was imposed by the Standard Time Act of 1918, which
# was the first nationwide legal time standard, and apparently
# time was just called "Standard Time" or "Daylight Saving Time".
# From Paul Eggert (2019-06-04):
# Here is the legal basis for the US federal rules.
# * Public Law 65-106 (1918-03-19) implemented standard and daylight saving
# time for the first time across the US, springing forward on March's last
# Sunday and falling back on October's last Sunday.
# https://www.loc.gov/law/help/statutes-at-large/65th-congress/session-2/c65s2ch24.pdf
# * Public Law 66-40 (1919-08-20) repealed DST on October 1919's last Sunday.
# https://www.loc.gov/law/help/statutes-at-large/66th-congress/session-1/c66s1ch51.pdf
# * Public Law 77-403 (1942-01-20) started wartime DST on 1942-02-09.
# https://www.loc.gov/law/help/statutes-at-large/77th-congress/session-2/c77s2ch7.pdf
# * Public Law 79-187 (1945-09-25) ended wartime DST on 1945-09-30.
# https://www.loc.gov/law/help/statutes-at-large/79th-congress/session-1/c79s1ch388.pdf
# * Public Law 89-387 (1966-04-13) reinstituted a national standard for DST,
# from April's last Sunday to October's last Sunday, effective 1967.
# https://www.govinfo.gov/content/pkg/STATUTE-80/pdf/STATUTE-80-Pg107.pdf
# * Public Law 93-182 (1973-12-15) moved the 1974 spring-forward to 01-06.
# https://www.govinfo.gov/content/pkg/STATUTE-87/pdf/STATUTE-87-Pg707.pdf
# * Public Law 93-434 (1974-10-05) moved the 1975 spring-forward to
# February's last Sunday.
# https://www.govinfo.gov/content/pkg/STATUTE-88/pdf/STATUTE-88-Pg1209.pdf
# * Public Law 99-359 (1986-07-08) moved the spring-forward to April's first
# Sunday.
# https://www.govinfo.gov/content/pkg/STATUTE-100/pdf/STATUTE-100-Pg764.pdf
# * Public Law 109-58 (2005-08-08), effective 2007, moved the spring-forward
# to March's second Sunday and the fall-back to November's first Sunday.
# https://www.govinfo.gov/content/pkg/PLAW-109publ58/pdf/PLAW-109publ58.pdf
# All transitions are at 02:00 local time.
# From Arthur David Olson:
# Before the Uniform Time Act of 1966 took effect in 1967, observance of
# Daylight Saving Time in the US was by local option, except during wartime.
# From Arthur David Olson (2000-09-25):
# Last night I heard part of a rebroadcast of a 1945 Arch Oboler radio drama.
# In the introduction, Oboler spoke of "Eastern Peace Time."
# An AltaVista search turned up:
# https://web.archive.org/web/20000926032210/http://rowayton.org/rhs/hstaug45.html
# "When the time is announced over the radio now, it is 'Eastern Peace
# Time' instead of the old familiar 'Eastern War Time.' Peace is wonderful."
# (August 1945) by way of confirmation.
#
# From Paul Eggert (2017-09-23):
# This was the V-J Day issue of the Clamdigger, a Rowayton, CT newsletter.
# From Joseph Gallant citing
# George H. Douglas, _The Early Days of Radio Broadcasting_ (1987):
# At 7 P.M. (Eastern War Time) [on 1945-08-14], the networks were set
# to switch to London for Attlee's address, but the American people
# never got to hear his speech live. According to one press account,
# CBS' Bob Trout was first to announce the word of Japan's surrender,
# but a few seconds later, NBC, ABC and Mutual also flashed the word
# of surrender, all of whom interrupting the bells of Big Ben in
# London which were to precede Mr. Attlee's speech.
# From Paul Eggert (2003-02-09): It was Robert St John, not Bob Trout. From
# Myrna Oliver's obituary of St John on page B16 of today's Los Angeles Times:
#
# ... a war-weary U.S. clung to radios, awaiting word of Japan's surrender.
# Any announcement from Asia would reach St. John's New York newsroom on a
# wire service teletype machine, which had prescribed signals for major news.
# Associated Press, for example, would ring five bells before spewing out
# typed copy of an important story, and 10 bells for news "of transcendental
# importance."
#
# On Aug. 14, stalling while talking steadily into the NBC networks' open
# microphone, St. John heard five bells and waited only to hear a sixth bell,
# before announcing confidently: "Ladies and gentlemen, World War II is over.
# The Japanese have agreed to our surrender terms."
#
# He had scored a 20-second scoop on other broadcasters.
# From Arthur David Olson (2005-08-22):
# Paul has been careful to use the "US" rules only in those locations
# that are part of the United States; this reflects the real scope of
# U.S. government action. So even though the "US" rules have changed
# in the latest release, other countries won't be affected.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule US 1918 1919 - Mar lastSun 2:00 1:00 D
Rule US 1918 1919 - Oct lastSun 2:00 0 S
Rule US 1942 only - Feb 9 2:00 1:00 W # War
Rule US 1945 only - Aug 14 23:00u 1:00 P # Peace
Rule US 1945 only - Sep 30 2:00 0 S
Rule US 1967 2006 - Oct lastSun 2:00 0 S
Rule US 1967 1973 - Apr lastSun 2:00 1:00 D
Rule US 1974 only - Jan 6 2:00 1:00 D
Rule US 1975 only - Feb lastSun 2:00 1:00 D
Rule US 1976 1986 - Apr lastSun 2:00 1:00 D
Rule US 1987 2006 - Apr Sun>=1 2:00 1:00 D
Rule US 2007 max - Mar Sun>=8 2:00 1:00 D
Rule US 2007 max - Nov Sun>=1 2:00 0 S
# From Arthur David Olson, 2005-12-19
# We generate the files specified below to guard against old files with
# obsolete information being left in the time zone binary directory.
# We limit the list to names that have appeared in previous versions of
# this time zone package.
# We do these as separate Zones rather than as Links to avoid problems if
# a particular place changes whether it observes DST.
# We put these specifications here in the northamerica file both to
# increase the chances that they'll actually get compiled and to
# avoid the need to duplicate the US rules in another file.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone EST -5:00 - EST
Zone MST -7:00 - MST
Zone HST -10:00 - HST
Zone EST5EDT -5:00 US E%sT
Zone CST6CDT -6:00 US C%sT
Zone MST7MDT -7:00 US M%sT
Zone PST8PDT -8:00 US P%sT
# From U. S. Naval Observatory (1989-01-19):
# USA EASTERN 5 H BEHIND UTC NEW YORK, WASHINGTON
# USA EASTERN 4 H BEHIND UTC APR 3 - OCT 30
# USA CENTRAL 6 H BEHIND UTC CHICAGO, HOUSTON
# USA CENTRAL 5 H BEHIND UTC APR 3 - OCT 30
# USA MOUNTAIN 7 H BEHIND UTC DENVER
# USA MOUNTAIN 6 H BEHIND UTC APR 3 - OCT 30
# USA PACIFIC 8 H BEHIND UTC L.A., SAN FRANCISCO
# USA PACIFIC 7 H BEHIND UTC APR 3 - OCT 30
# USA ALASKA STD 9 H BEHIND UTC MOST OF ALASKA (AKST)
# USA ALASKA STD 8 H BEHIND UTC APR 3 - OCT 30 (AKDT)
# USA ALEUTIAN 10 H BEHIND UTC ISLANDS WEST OF 170W
# USA " 9 H BEHIND UTC APR 3 - OCT 30
# USA HAWAII 10 H BEHIND UTC
# USA BERING 11 H BEHIND UTC SAMOA, MIDWAY
# From Arthur David Olson (1989-01-21):
# The above dates are for 1988.
# Note the "AKST" and "AKDT" abbreviations, the claim that there's
# no DST in Samoa, and the claim that there is DST in Alaska and the
# Aleutians.
# From Arthur David Olson (1988-02-13):
# Legal standard time zone names, from United States Code (1982 Edition and
# Supplement III), Title 15, Chapter 6, Section 260 and forward. First, names
# up to 1967-04-01 (when most provisions of the Uniform Time Act of 1966
# took effect), as explained in sections 263 and 261:
# (none)
# United States standard eastern time
# United States standard mountain time
# United States standard central time
# United States standard Pacific time
# (none)
# United States standard Alaska time
# (none)
# Next, names from 1967-04-01 until 1983-11-30 (the date for
# public law 98-181):
# Atlantic standard time
# eastern standard time
# central standard time
# mountain standard time
# Pacific standard time
# Yukon standard time
# Alaska-Hawaii standard time
# Bering standard time
# And after 1983-11-30:
# Atlantic standard time
# eastern standard time
# central standard time
# mountain standard time
# Pacific standard time
# Alaska standard time
# Hawaii-Aleutian standard time
# Samoa standard time
# The law doesn't give abbreviations.
#
# From Paul Eggert (2016-12-19):
# Here are URLs for the 1918 and 1966 legislation:
# http://uscode.house.gov/statviewer.htm?volume=40&page=451
# http://uscode.house.gov/statviewer.htm?volume=80&page=108
# Although the 1918 names were officially "United States Standard
# Eastern Time" and similarly for "Central", "Mountain", "Pacific",
# and "Alaska", in practice "Standard" was placed just before "Time",
# as codified in 1966. In practice, Alaska time was abbreviated "AST"
# before 1968. Summarizing the 1967 name changes:
# 1918 names 1967 names
# -08 Standard Pacific Time (PST) Pacific standard time (PST)
# -09 (unofficial) Yukon (YST) Yukon standard time (YST)
# -10 Standard Alaska Time (AST) Alaska-Hawaii standard time (AHST)
# -11 (unofficial) Nome (NST) Bering standard time (BST)
#
# From Paul Eggert (2000-01-08), following a heads-up from Rives McDow:
# Public law 106-564 (2000-12-23) introduced ... "Chamorro Standard Time"
# for time in Guam and the Northern Marianas. See the file "australasia".
#
# From Paul Eggert (2015-04-17):
# HST and HDT are standardized abbreviations for Hawaii-Aleutian
# standard and daylight times. See section 9.47 (p 234) of the
# U.S. Government Printing Office Style Manual (2008)
# https://www.gpo.gov/fdsys/pkg/GPO-STYLEMANUAL-2008/pdf/GPO-STYLEMANUAL-2008.pdf
# From Arthur David Olson, 2005-08-09
# The following was signed into law on 2005-08-08.
#
# H.R. 6, Energy Policy Act of 2005, SEC. 110. DAYLIGHT SAVINGS.
# (a) Amendment.--Section 3(a) of the Uniform Time Act of 1966 (15
# U.S.C. 260a(a)) is amended--
# (1) by striking "first Sunday of April" and inserting "second
# Sunday of March"; and
# (2) by striking "last Sunday of October" and inserting "first
# Sunday of November'.
# (b) Effective Date.--Subsection (a) shall take effect 1 year after the
# date of enactment of this Act or March 1, 2007, whichever is later.
# (c) Report to Congress.--Not later than 9 months after the effective
# date stated in subsection (b), the Secretary shall report to Congress
# on the impact of this section on energy consumption in the United
# States.
# (d) Right to Revert.--Congress retains the right to revert the
# Daylight Saving Time back to the 2005 time schedules once the
# Department study is complete.
# US eastern time, represented by New York
# Connecticut, Delaware, District of Columbia, most of Florida,
# Georgia, southeast Indiana (Dearborn and Ohio counties), eastern Kentucky
# (except America/Kentucky/Louisville below), Maine, Maryland, Massachusetts,
# New Hampshire, New Jersey, New York, North Carolina, Ohio,
# Pennsylvania, Rhode Island, South Carolina, eastern Tennessee,
# Vermont, Virginia, West Virginia
# From Dave Cantor (2004-11-02):
# Early this summer I had the occasion to visit the Mount Washington
# Observatory weather station atop (of course!) Mount Washington [, NH]....
# One of the staff members said that the station was on Eastern Standard Time
# and didn't change their clocks for Daylight Saving ... so that their
# reports will always have times which are 5 hours behind UTC.
# From Paul Eggert (2005-08-26):
# According to today's Huntsville Times
# http://www.al.com/news/huntsvilletimes/index.ssf?/base/news/1125047783228320.xml&coll=1
# a few towns on Alabama's "eastern border with Georgia, such as Phenix City
# in Russell County, Lanett in Chambers County and some towns in Lee County,
# set their watches and clocks on Eastern time." It quotes H.H. "Bubba"
# Roberts, city administrator in Phenix City. as saying "We are in the Central
# time zone, but we do go by the Eastern time zone because so many people work
# in Columbus."
#
# From Paul Eggert (2017-02-22):
# Four cities are involved. The two not mentioned above are Smiths Station
# and Valley. Barbara Brooks, Valley's assistant treasurer, heard it started
# because West Point Pepperell textile mills were in Alabama while the
# corporate office was in Georgia, and residents voted to keep Eastern
# time even after the mills closed. See: Kazek K. Did you know which
# Alabama towns are in a different time zone? al.com 2017-02-06.
# http://www.al.com/living/index.ssf/2017/02/do_you_know_which_alabama_town.html
# From Paul Eggert (2014-09-06):
# Monthly Notices of the Royal Astronomical Society 44, 4 (1884-02-08), 208
# says that New York City Hall time was 3 minutes 58.4 seconds fast of
# Eastern time (i.e., -4:56:01.6) just before the 1883 switch. Round to the
# nearest second.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
Rule NYC 1920 only - Mar lastSun 2:00 1:00 D
Rule NYC 1920 only - Oct lastSun 2:00 0 S
Rule NYC 1921 1966 - Apr lastSun 2:00 1:00 D
Rule NYC 1921 1954 - Sep lastSun 2:00 0 S
Rule NYC 1955 1966 - Oct lastSun 2:00 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/New_York -4:56:02 - LMT 1883 Nov 18 12:03:58
-5:00 US E%sT 1920
-5:00 NYC E%sT 1942
-5:00 US E%sT 1946
-5:00 NYC E%sT 1967
-5:00 US E%sT
# US central time, represented by Chicago
# Alabama, Arkansas, Florida panhandle (Bay, Calhoun, Escambia,
# Gulf, Holmes, Jackson, Okaloosa, Santa Rosa, Walton, and
# Washington counties), Illinois, western Indiana
# (Gibson, Jasper, Lake, LaPorte, Newton, Porter, Posey, Spencer,
# Vanderburgh, and Warrick counties), Iowa, most of Kansas, western
# Kentucky, Louisiana, Minnesota, Mississippi, Missouri, eastern
# Nebraska, eastern North Dakota, Oklahoma, eastern South Dakota,
# western Tennessee, most of Texas, Wisconsin
# From Paul Eggert (2018-01-07):
# In 1869 the Chicago Astronomical Society contracted with the city to keep
# time. Though delayed by the Great Fire, by 1880 a wire ran from the
# Dearborn Observatory (on the University of Chicago campus) to City Hall,
# which then sent signals to police and fire stations. However, railroads got
# their time signals from the Allegheny Observatory, the Madison Observatory,
# the Ann Arbor Observatory, etc., so their clocks did not agree with each
# other or with the city's official time. The confusion took some years to
# clear up. See:
# Moser M. How Chicago gave America its time zones. Chicago. 2018-01-04.
# http://www.chicagomag.com/city-life/January-2018/How-Chicago-Gave-America-Its-Time-Zones/
# From Larry M. Smith (2006-04-26) re Wisconsin:
# https://docs.legis.wisconsin.gov/statutes/statutes/175.pdf
# is currently enforced at the 01:00 time of change. Because the local
# "bar time" in the state corresponds to 02:00, a number of citations
# are issued for the "sale of class 'B' alcohol after prohibited
# hours" within the deviated hour of this change every year....
#
# From Douglas R. Bomberg (2007-03-12):
# Wisconsin has enacted (nearly eleventh-hour) legislation to get WI
# Statue 175 closer in synch with the US Congress' intent....
# https://docs.legis.wisconsin.gov/2007/related/acts/3
# From an email administrator of the City of Fort Pierre, SD (2015-12-21):
# Fort Pierre is technically located in the Mountain time zone as is
# the rest of Stanley County. Most of Stanley County and Fort Pierre
# uses the Central time zone due to doing most of their business in
# Pierre so it simplifies schedules. I have lived in Stanley County
# all my life and it has been that way since I can remember. (43 years!)
#
# From Paul Eggert (2015-12-25):
# Assume this practice predates 1970, so Fort Pierre can use America/Chicago.
+# From Paul Eggert (2015-04-06):
+# In 1950s Nashville a public clock had dueling faces, one for conservatives
+# and the other for liberals; the two sides didn't agree about the time of day.
+# I haven't found a photo of this clock, nor have I tracked down the TIME
+# magazine report cited below, but here's the story as told by the late
+# American journalist John Seigenthaler, who was there:
+#
+# "The two [newspaper] owners held strongly contrasting political and
+# ideological views. Evans was a New South liberal, Stahlman an Old South
+# conservative, and their two papers frequently clashed editorially, often on
+# the same day.... In the 1950s as the state legislature was grappling with
+# the question of whether to approve daylight saving time for the entire state,
+# TIME magazine reported:
+#
+# "'The Nashville Banner and The Nashville Tennessean rarely agree on anything
+# but the time of day - and last week they couldn't agree on that.'
+#
+# "It was all too true. The clock on the front of the building had two faces -
+# The Tennessean side of the building facing west, the other, east. When it
+# was high noon Banner time, it was 11 a.m. Tennessean time."
+#
+# Seigenthaler J. For 100 years, Tennessean had it covered.
+# The Tennessean 2007-05-11, republished 2015-04-06.
+# https://www.tennessean.com/story/insider/extras/2015/04/06/archives-seigenthaler-for-100-years-the-tennessean-had-it-covered/25348545/
+
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
Rule Chicago 1920 only - Jun 13 2:00 1:00 D
Rule Chicago 1920 1921 - Oct lastSun 2:00 0 S
Rule Chicago 1921 only - Mar lastSun 2:00 1:00 D
Rule Chicago 1922 1966 - Apr lastSun 2:00 1:00 D
Rule Chicago 1922 1954 - Sep lastSun 2:00 0 S
Rule Chicago 1955 1966 - Oct lastSun 2:00 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Chicago -5:50:36 - LMT 1883 Nov 18 12:09:24
-6:00 US C%sT 1920
-6:00 Chicago C%sT 1936 Mar 1 2:00
-5:00 - EST 1936 Nov 15 2:00
-6:00 Chicago C%sT 1942
-6:00 US C%sT 1946
-6:00 Chicago C%sT 1967
-6:00 US C%sT
# Oliver County, ND switched from mountain to central time on 1992-10-25.
Zone America/North_Dakota/Center -6:45:12 - LMT 1883 Nov 18 12:14:48
-7:00 US M%sT 1992 Oct 25 2:00
-6:00 US C%sT
# Morton County, ND, switched from mountain to central time on
# 2003-10-26, except for the area around Mandan which was already central time.
# See <http://dmses.dot.gov/docimages/p63/135818.pdf>.
# Officially this switch also included part of Sioux County, and
# Jones, Mellette, and Todd Counties in South Dakota;
# but in practice these other counties were already observing central time.
# See <http://www.epa.gov/fedrgstr/EPA-IMPACT/2003/October/Day-28/i27056.htm>.
Zone America/North_Dakota/New_Salem -6:45:39 - LMT 1883 Nov 18 12:14:21
-7:00 US M%sT 2003 Oct 26 2:00
-6:00 US C%sT
# From Josh Findley (2011-01-21):
# ...it appears that Mercer County, North Dakota, changed from the
# mountain time zone to the central time zone at the last transition from
# daylight-saving to standard time (on Nov. 7, 2010):
# https://www.gpo.gov/fdsys/pkg/FR-2010-09-29/html/2010-24376.htm
# http://www.bismarcktribune.com/news/local/article_1eb1b588-c758-11df-b472-001cc4c03286.html
# From Andy Lipscomb (2011-01-24):
# ...according to the Census Bureau, the largest city is Beulah (although
# it's commonly referred to as Beulah-Hazen, with Hazen being the next
# largest city in Mercer County). Google Maps places Beulah's city hall
# at 47° 15' 51" N, 101° 46' 40" W, which yields an offset of 6h47'07".
Zone America/North_Dakota/Beulah -6:47:07 - LMT 1883 Nov 18 12:12:53
-7:00 US M%sT 2010 Nov 7 2:00
-6:00 US C%sT
# US mountain time, represented by Denver
#
# Colorado, far western Kansas, Montana, western
# Nebraska, Nevada border (Jackpot, Owyhee, and Mountain City),
# New Mexico, southwestern North Dakota,
# western South Dakota, far western Texas (El Paso County, Hudspeth County,
# and Pine Springs and Nickel Creek in Culberson County), Utah, Wyoming
#
# From Paul Eggert (2018-10-25):
# On 1921-03-04 federal law placed all of Texas into the central time zone.
# However, El Paso ignored the law for decades and continued to observe
# mountain time, on the grounds that that's what they had always done
# and they weren't about to let the federal government tell them what to do.
# Eventually the federal government gave in and changed the law on
# 1970-04-10 to match what El Paso was actually doing. Although
# that's slightly after our 1970 cutoff, there is no need to create a
# separate zone for El Paso since they were ignoring the law anyway. See:
# Long T. El Pasoans were time rebels, fought to stay in Mountain zone.
# El Paso Times. 2018-10-24 06:40 -06.
# https://www.elpasotimes.com/story/news/local/el-paso/2018/10/24/el-pasoans-were-time-rebels-fought-stay-mountain-zone/1744509002/
#
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
Rule Denver 1920 1921 - Mar lastSun 2:00 1:00 D
Rule Denver 1920 only - Oct lastSun 2:00 0 S
Rule Denver 1921 only - May 22 2:00 0 S
Rule Denver 1965 1966 - Apr lastSun 2:00 1:00 D
Rule Denver 1965 1966 - Oct lastSun 2:00 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Denver -6:59:56 - LMT 1883 Nov 18 12:00:04
-7:00 US M%sT 1920
-7:00 Denver M%sT 1942
-7:00 US M%sT 1946
-7:00 Denver M%sT 1967
-7:00 US M%sT
# US Pacific time, represented by Los Angeles
#
# California, northern Idaho (Benewah, Bonner, Boundary, Clearwater,
# Kootenai, Latah, Lewis, Nez Perce, and Shoshone counties, Idaho county
# north of the Salmon River, and the towns of Burgdorf and Warren),
# Nevada (except West Wendover), Oregon (except the northern ¾ of
# Malheur county), and Washington
# From Paul Eggert (2016-08-20):
# In early February 1948, in response to California's electricity shortage,
# PG&E changed power frequency from 60 to 59.5 Hz during daylight hours,
# causing electric clocks to lose six minutes per day. (This did not change
# legal time, and is not part of the data here.) See:
# Ross SA. An energy crisis from the past: Northern California in 1948.
# Working Paper No. 8, Institute of Governmental Studies, UC Berkeley,
# 1973-11. https://escholarship.org/uc/item/8x22k30c
#
# In another measure to save electricity, DST was instituted from 1948-03-14
# at 02:01 to 1949-01-16 at 02:00, with the governor having the option to move
# the fallback transition earlier. See pages 3-4 of:
# http://clerk.assembly.ca.gov/sites/clerk.assembly.ca.gov/files/archive/Statutes/1948/48Vol1_Chapters.pdf
#
# In response:
#
# Governor Warren received a torrent of objecting mail, and it is not too much
# to speculate that the objections to Daylight Saving Time were one important
# factor in the defeat of the Dewey-Warren Presidential ticket in California.
# -- Ross, p 25
#
# On December 8 the governor exercised the option, setting the date to January 1
# (LA Times 1948-12-09). The transition time was 02:00 (LA Times 1949-01-01).
#
# Despite the controversy, in 1949 California voters approved Proposition 12,
# which established DST from April's last Sunday at 01:00 until September's
# last Sunday at 02:00. This was amended by 1962's Proposition 6, which changed
# the fall-back date to October's last Sunday. See:
# https://repository.uchastings.edu/cgi/viewcontent.cgi?article=1501&context=ca_ballot_props
# https://repository.uchastings.edu/cgi/viewcontent.cgi?article=1636&context=ca_ballot_props
#
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
Rule CA 1948 only - Mar 14 2:01 1:00 D
Rule CA 1949 only - Jan 1 2:00 0 S
Rule CA 1950 1966 - Apr lastSun 1:00 1:00 D
Rule CA 1950 1961 - Sep lastSun 2:00 0 S
Rule CA 1962 1966 - Oct lastSun 2:00 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Los_Angeles -7:52:58 - LMT 1883 Nov 18 12:07:02
-8:00 US P%sT 1946
-8:00 CA P%sT 1967
-8:00 US P%sT
# Alaska
# AK%sT is the modern abbreviation for -09 per USNO.
#
# From Paul Eggert (2017-06-15):
# Howse writes that Alaska switched from the Julian to the Gregorian calendar,
# and from east-of-GMT to west-of-GMT days, when the US bought it from Russia.
# On Friday, 1867-10-18 (Gregorian), at precisely 15:30 local time, the
# Russian forts and fleet at Sitka fired salutes to mark the ceremony of
# formal transfer. See the Sacramento Daily Union (1867-11-14), p 3, col 2.
# https://cdnc.ucr.edu/cgi-bin/cdnc?a=d&d=SDU18671114.2.12.1
# Sitka workers did not change their calendars until Sunday, 1867-10-20,
# and so celebrated two Sundays that week. See: Ahllund T (tr Hallamaa P).
# From the memoirs of a Finnish workman. Alaska History. 2006 Fall;21(2):1-25.
# http://alaskahistoricalsociety.org/wp-content/uploads/2016/12/Ahllund-2006-Memoirs-of-a-Finnish-Workman.pdf
# Include only the time zone part of this transition, ignoring the switch
# from Julian to Gregorian, since we can't represent the Julian calendar.
#
# As far as we know, of the locations mentioned below only Sitka was
# permanently inhabited in 1867 by anyone using either calendar.
# (Yakutat was colonized by the Russians in 1799, but the settlement was
# destroyed in 1805 by a Yakutat-kon war party.) Many of Alaska's inhabitants
# were unaware of the US acquisition of Alaska, much less of any calendar or
# time change. However, the Russian-influenced part of Alaska did observe
# Russian time, and it is more accurate to model this than to ignore it.
# The database format requires an exact transition time; use the Russian
# salute as a somewhat-arbitrary time for the formal transfer of control for
# all of Alaska. Sitka's UTC offset is -9:01:13; adjust its 15:30 to the
# local times of other Alaskan locations so that they change simultaneously.
# From Paul Eggert (2014-07-18):
# One opinion of the early-1980s turmoil in Alaska over time zones and
# daylight saving time appeared as graffiti on a Juneau airport wall:
# "Welcome to Juneau. Please turn your watch back to the 19th century."
# See: Turner W. Alaska's four time zones now two. NY Times 1983-11-01.
# http://www.nytimes.com/1983/11/01/us/alaska-s-four-time-zones-now-two.html
#
# Steve Ferguson (2011-01-31) referred to the following source:
# Norris F. Keeping time in Alaska: national directives, local response.
# Alaska History 2001;16(1-2).
# http://alaskahistoricalsociety.org/discover-alaska/glimpses-of-the-past/keeping-time-in-alaska/
# From Arthur David Olson (2011-02-01):
# Here's database-relevant material from the 2001 "Alaska History" article:
#
# On September 20 [1979]...DOT...officials decreed that on April 27,
# 1980, Juneau and other nearby communities would move to Yukon Time.
# Sitka, Petersburg, Wrangell, and Ketchikan, however, would remain on
# Pacific Time.
#
# ...on September 22, 1980, DOT Secretary Neil E. Goldschmidt rescinded the
# Department's September 1979 decision. Juneau and other communities in
# northern Southeast reverted to Pacific Time on October 26.
#
# On October 28 [1983]...the Metlakatla Indian Community Council voted
# unanimously to keep the reservation on Pacific Time.
#
# According to DOT official Joanne Petrie, Indian reservations are not
# bound to follow time zones imposed by neighboring jurisdictions.
#
# (The last is consistent with how the database now handles the Navajo
# Nation.)
# From Arthur David Olson (2011-02-09):
# I just spoke by phone with a staff member at the Metlakatla Indian
# Community office (using contact information available at
# http://www.commerce.state.ak.us/dca/commdb/CIS.cfm?Comm_Boro_name=Metlakatla
# It's shortly after 1:00 here on the east coast of the United States;
# the staffer said it was shortly after 10:00 there. When I asked whether
# that meant they were on Pacific time, they said no - they were on their
# own time. I asked about daylight saving; they said it wasn't used. I
# did not inquire about practices in the past.
# From Arthur David Olson (2011-08-17):
# For lack of better information, assume that Metlakatla's
# abandonment of use of daylight saving resulted from the 1983 vote.
# From Steffen Thorsen (2015-11-09):
# It seems Metlakatla did go off PST on Sunday, November 1, changing
# their time to AKST and are going to follow Alaska's DST, switching
# between AKST and AKDT from now on....
# https://www.krbd.org/2015/10/30/annette-island-times-they-are-a-changing/
# From Ryan Stanley (2018-11-06):
# The Metlakatla community in Alaska has decided not to change its
# clock back an hour starting on November 4th, 2018 (day before yesterday).
# They will be gmtoff=-28800 year-round.
# https://www.facebook.com/141055983004923/photos/pb.141055983004923.-2207520000.1541465673./569081370202380/
# From Paul Eggert (2018-12-16):
# In a 2018-12-11 special election, Metlakatla voted to go back to
# Alaska time (including daylight saving time) starting next year.
# https://www.krbd.org/2018/12/12/metlakatla-to-follow-alaska-standard-time-allow-liquor-sales/
#
# From Ryan Stanley (2019-01-11):
# The community will be changing back on the 20th of this month...
# From Tim Parenti (2019-01-11):
# Per an announcement on the Metlakatla community's official Facebook page, the
# "fall back" will be on Sunday 2019-01-20 at 02:00:
# https://www.facebook.com/141055983004923/photos/607150969728753/
# So they won't be waiting for Alaska to join them on 2019-03-10, but will
# rather change their clocks twice in seven weeks.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Juneau 15:02:19 - LMT 1867 Oct 19 15:33:32
-8:57:41 - LMT 1900 Aug 20 12:00
-8:00 - PST 1942
-8:00 US P%sT 1946
-8:00 - PST 1969
-8:00 US P%sT 1980 Apr 27 2:00
-9:00 US Y%sT 1980 Oct 26 2:00
-8:00 US P%sT 1983 Oct 30 2:00
-9:00 US Y%sT 1983 Nov 30
-9:00 US AK%sT
Zone America/Sitka 14:58:47 - LMT 1867 Oct 19 15:30
-9:01:13 - LMT 1900 Aug 20 12:00
-8:00 - PST 1942
-8:00 US P%sT 1946
-8:00 - PST 1969
-8:00 US P%sT 1983 Oct 30 2:00
-9:00 US Y%sT 1983 Nov 30
-9:00 US AK%sT
Zone America/Metlakatla 15:13:42 - LMT 1867 Oct 19 15:44:55
-8:46:18 - LMT 1900 Aug 20 12:00
-8:00 - PST 1942
-8:00 US P%sT 1946
-8:00 - PST 1969
-8:00 US P%sT 1983 Oct 30 2:00
-8:00 - PST 2015 Nov 1 2:00
-9:00 US AK%sT 2018 Nov 4 2:00
-8:00 - PST 2019 Jan 20 2:00
-9:00 US AK%sT
Zone America/Yakutat 14:41:05 - LMT 1867 Oct 19 15:12:18
-9:18:55 - LMT 1900 Aug 20 12:00
-9:00 - YST 1942
-9:00 US Y%sT 1946
-9:00 - YST 1969
-9:00 US Y%sT 1983 Nov 30
-9:00 US AK%sT
Zone America/Anchorage 14:00:24 - LMT 1867 Oct 19 14:31:37
-9:59:36 - LMT 1900 Aug 20 12:00
-10:00 - AST 1942
-10:00 US A%sT 1967 Apr
-10:00 - AHST 1969
-10:00 US AH%sT 1983 Oct 30 2:00
-9:00 US Y%sT 1983 Nov 30
-9:00 US AK%sT
Zone America/Nome 12:58:22 - LMT 1867 Oct 19 13:29:35
-11:01:38 - LMT 1900 Aug 20 12:00
-11:00 - NST 1942
-11:00 US N%sT 1946
-11:00 - NST 1967 Apr
-11:00 - BST 1969
-11:00 US B%sT 1983 Oct 30 2:00
-9:00 US Y%sT 1983 Nov 30
-9:00 US AK%sT
Zone America/Adak 12:13:22 - LMT 1867 Oct 19 12:44:35
-11:46:38 - LMT 1900 Aug 20 12:00
-11:00 - NST 1942
-11:00 US N%sT 1946
-11:00 - NST 1967 Apr
-11:00 - BST 1969
-11:00 US B%sT 1983 Oct 30 2:00
-10:00 US AH%sT 1983 Nov 30
-10:00 US H%sT
# The following switches don't quite make our 1970 cutoff.
#
# Shanks writes that part of southwest Alaska (e.g. Aniak)
# switched from -11:00 to -10:00 on 1968-09-22 at 02:00,
# and another part (e.g. Akiak) made the same switch five weeks later.
#
# From David Flater (2004-11-09):
# In e-mail, 2004-11-02, Ray Hudson, historian/liaison to the Unalaska
# Historic Preservation Commission, provided this information, which
# suggests that Unalaska deviated from statutory time from early 1967
# possibly until 1983:
#
# Minutes of the Unalaska City Council Meeting, January 10, 1967:
# "Except for St. Paul and Akutan, Unalaska is the only important
# location not on Alaska Standard Time. The following resolution was
# made by William Robinson and seconded by Henry Swanson: Be it
# resolved that the City of Unalaska hereby goes to Alaska Standard
# Time as of midnight Friday, January 13, 1967 (1 A.M. Saturday,
# January 14, Alaska Standard Time.) This resolution was passed with
# three votes for and one against."
# Hawaii
# From Arthur David Olson (2010-12-09):
# "Hawaiian Time" by Robert C. Schmitt and Doak C. Cox appears on pages 207-225
# of volume 26 of The Hawaiian Journal of History (1992). As of 2010-12-09,
# the article is available at
# https://evols.library.manoa.hawaii.edu/bitstream/10524/239/2/JL26215.pdf
# and indicates that standard time was adopted effective noon, January
# 13, 1896 (page 218), that in "1933, the Legislature decreed daylight
# saving for the period between the last Sunday of each April and the
# last Sunday of each September, but less than a month later repealed the
# act," (page 220), that year-round daylight saving time was in effect
# from 1942-02-09 to 1945-09-30 (page 221, with no time of day given for
# when clocks changed) and that clocks were changed by 30 minutes
# effective the second Sunday of June, 1947 (page 219, with no time of
# day given for when clocks changed). A footnote for the 1933 changes
# cites Session Laws of Hawaii 1933, "Act. 90 (approved 26 Apr. 1933)
# and Act 163 (approved 21 May 1933)."
# From Arthur David Olson (2011-01-19):
# The following is from "Laws of the Territory of Hawaii Passed by the
# Seventeenth Legislature: Regular Session 1933," available (as of
# 2011-01-19) at American University's Pence Law Library. Page 85: "Act
# 90...At 2 o'clock ante meridian of the last Sunday in April of each
# year, the standard time of this Territory shall be advanced one
# hour...This Act shall take effect upon its approval. Approved this 26th
# day of April, A. D. 1933. LAWRENCE M JUDD, Governor of the Territory of
# Hawaii." Page 172: "Act 163...Act 90 of the Session Laws of 1933 is
# hereby repealed...This Act shall take effect upon its approval, upon
# which date the standard time of this Territory shall be restored to
# that existing immediately prior to the taking effect of said Act 90.
# Approved this 21st day of May, A. D. 1933. LAWRENCE M. JUDD, Governor
# of the Territory of Hawaii."
#
# Note that 1933-05-21 was a Sunday.
# We're left to guess the time of day when Act 163 was approved; guess noon.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Honolulu -10:31:26 - LMT 1896 Jan 13 12:00
-10:30 - HST 1933 Apr 30 2:00
-10:30 1:00 HDT 1933 May 21 12:00
-10:30 US H%sT 1947 Jun 8 2:00
-10:00 - HST
# Now we turn to US areas that have diverged from the consensus since 1970.
# Arizona mostly uses MST.
# From Paul Eggert (2002-10-20):
#
# The information in the rest of this paragraph is derived from the
# Daylight Saving Time web page
# <http://www.dlapr.lib.az.us/links/daylight.htm> (2002-01-23)
# maintained by the Arizona State Library, Archives and Public Records.
# Between 1944-01-01 and 1944-04-01 the State of Arizona used standard
# time, but by federal law railroads, airlines, bus lines, military
# personnel, and some engaged in interstate commerce continued to
# observe war (i.e., daylight saving) time. The 1944-03-17 Phoenix
# Gazette says that was the date the law changed, and that 04-01 was
# the date the state's clocks would change. In 1945 the State of
# Arizona used standard time all year, again with exceptions only as
# mandated by federal law. Arizona observed DST in 1967, but Arizona
# Laws 1968, ch. 183 (effective 1968-03-21) repealed DST.
#
# Shanks says the 1944 experiment came to an end on 1944-03-17.
# Go with the Arizona State Library instead.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Phoenix -7:28:18 - LMT 1883 Nov 18 11:31:42
-7:00 US M%sT 1944 Jan 1 0:01
-7:00 - MST 1944 Apr 1 0:01
-7:00 US M%sT 1944 Oct 1 0:01
-7:00 - MST 1967
-7:00 US M%sT 1968 Mar 21
-7:00 - MST
# From Arthur David Olson (1988-02-13):
# A writer from the Inter Tribal Council of Arizona, Inc.,
# notes in private correspondence dated 1987-12-28 that "Presently, only the
# Navajo Nation participates in the Daylight Saving Time policy, due to its
# large size and location in three states." (The "only" means that other
# tribal nations don't use DST.)
#
# From Paul Eggert (2013-08-26):
# See America/Denver for a zone appropriate for the Navajo Nation.
# Southern Idaho (Ada, Adams, Bannock, Bear Lake, Bingham, Blaine,
# Boise, Bonneville, Butte, Camas, Canyon, Caribou, Cassia, Clark,
# Custer, Elmore, Franklin, Fremont, Gem, Gooding, Jefferson, Jerome,
# Lemhi, Lincoln, Madison, Minidoka, Oneida, Owyhee, Payette, Power,
# Teton, Twin Falls, Valley, Washington counties, and the southern
# quarter of Idaho county) and eastern Oregon (most of Malheur County)
# switched four weeks late in 1974.
#
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Boise -7:44:49 - LMT 1883 Nov 18 12:15:11
-8:00 US P%sT 1923 May 13 2:00
-7:00 US M%sT 1974
-7:00 - MST 1974 Feb 3 2:00
-7:00 US M%sT
# Indiana
#
# For a map of Indiana's time zone regions, see:
# https://en.wikipedia.org/wiki/Time_in_Indiana
#
# From Paul Eggert (2018-11-30):
# A brief but entertaining history of time in Indiana describes a 1949 debate
# in the Indiana House where city legislators (who favored "fast time")
# tussled with farm legislators (who didn't) over a bill to outlaw DST:
# "Lacking enough votes, the city faction tries to filibuster until time runs
# out on the session at midnight, but rural champion Rep. Herbert Copeland,
# R-Madison, leans over the gallery railing and forces the official clock
# back to 9 p.m., breaking it in the process. The clock sticks on 9 as the
# debate rages on into the night. The filibuster finally dies out and the
# bill passes, while outside the chamber, clocks read 3:30 a.m. In the end,
# it doesn't matter which side won. The law has no enforcement powers and
# is simply ignored by fast-time communities."
# How Indiana went from 'God's time' to split zones and daylight-saving.
# Indianapolis Star. 2018-11-27 14:58 -05.
# https://www.indystar.com/story/news/politics/2018/11/27/indianapolis-indiana-time-zone-history-central-eastern-daylight-savings-time/2126300002/
#
# From Paul Eggert (2007-08-17):
# Since 1970, most of Indiana has been like America/Indiana/Indianapolis,
# with the following exceptions:
#
# - Gibson, Jasper, Lake, LaPorte, Newton, Porter, Posey, Spencer,
# Vanderburgh, and Warrick counties have been like America/Chicago.
#
# - Dearborn and Ohio counties have been like America/New_York.
#
# - Clark, Floyd, and Harrison counties have been like
# America/Kentucky/Louisville.
#
# - Crawford, Daviess, Dubois, Knox, Martin, Perry, Pike, Pulaski, Starke,
# and Switzerland counties have their own time zone histories as noted below.
#
# Shanks partitioned Indiana into 345 regions, each with its own time history,
# and wrote "Even newspaper reports present contradictory information."
# Those Hoosiers! Such a flighty and changeable people!
# Fortunately, most of the complexity occurred before our cutoff date of 1970.
#
# Other than Indianapolis, the Indiana place names are so nondescript
# that they would be ambiguous if we left them at the 'America' level.
# So we reluctantly put them all in a subdirectory 'America/Indiana'.
# From Paul Eggert (2014-06-26):
# https://www.federalregister.gov/articles/2006/01/20/06-563/standard-time-zone-boundary-in-the-state-of-indiana
# says "DOT is relocating the time zone boundary in Indiana to move Starke,
# Pulaski, Knox, Daviess, Martin, Pike, Dubois, and Perry Counties from the
# Eastern Time Zone to the Central Time Zone.... The effective date of
# this rule is 2 a.m. EST Sunday, April 2, 2006, which is the
# changeover date from standard time to Daylight Saving Time."
# Strictly speaking, this meant the affected counties changed their
# clocks twice that night, but this obviously was in error. The intent
# was that 01:59:59 EST be followed by 02:00:00 CDT.
# From Gwillim Law (2007-02-10):
# The Associated Press has been reporting that Pulaski County, Indiana is
# going to switch from Central to Eastern Time on March 11, 2007....
# http://www.indystar.com/apps/pbcs.dll/article?AID=/20070207/LOCAL190108/702070524/0/LOCAL
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
Rule Indianapolis 1941 only - Jun 22 2:00 1:00 D
Rule Indianapolis 1941 1954 - Sep lastSun 2:00 0 S
Rule Indianapolis 1946 1954 - Apr lastSun 2:00 1:00 D
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Indiana/Indianapolis -5:44:38 - LMT 1883 Nov 18 12:15:22
-6:00 US C%sT 1920
-6:00 Indianapolis C%sT 1942
-6:00 US C%sT 1946
-6:00 Indianapolis C%sT 1955 Apr 24 2:00
-5:00 - EST 1957 Sep 29 2:00
-6:00 - CST 1958 Apr 27 2:00
-5:00 - EST 1969
-5:00 US E%sT 1971
-5:00 - EST 2006
-5:00 US E%sT
#
# Eastern Crawford County, Indiana, left its clocks alone in 1974,
# as well as from 1976 through 2005.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
Rule Marengo 1951 only - Apr lastSun 2:00 1:00 D
Rule Marengo 1951 only - Sep lastSun 2:00 0 S
Rule Marengo 1954 1960 - Apr lastSun 2:00 1:00 D
Rule Marengo 1954 1960 - Sep lastSun 2:00 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Indiana/Marengo -5:45:23 - LMT 1883 Nov 18 12:14:37
-6:00 US C%sT 1951
-6:00 Marengo C%sT 1961 Apr 30 2:00
-5:00 - EST 1969
-5:00 US E%sT 1974 Jan 6 2:00
-6:00 1:00 CDT 1974 Oct 27 2:00
-5:00 US E%sT 1976
-5:00 - EST 2006
-5:00 US E%sT
#
# Daviess, Dubois, Knox, and Martin Counties, Indiana,
# switched from eastern to central time in April 2006, then switched back
# in November 2007.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
Rule Vincennes 1946 only - Apr lastSun 2:00 1:00 D
Rule Vincennes 1946 only - Sep lastSun 2:00 0 S
Rule Vincennes 1953 1954 - Apr lastSun 2:00 1:00 D
Rule Vincennes 1953 1959 - Sep lastSun 2:00 0 S
Rule Vincennes 1955 only - May 1 0:00 1:00 D
Rule Vincennes 1956 1963 - Apr lastSun 2:00 1:00 D
Rule Vincennes 1960 only - Oct lastSun 2:00 0 S
Rule Vincennes 1961 only - Sep lastSun 2:00 0 S
Rule Vincennes 1962 1963 - Oct lastSun 2:00 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Indiana/Vincennes -5:50:07 - LMT 1883 Nov 18 12:09:53
-6:00 US C%sT 1946
-6:00 Vincennes C%sT 1964 Apr 26 2:00
-5:00 - EST 1969
-5:00 US E%sT 1971
-5:00 - EST 2006 Apr 2 2:00
-6:00 US C%sT 2007 Nov 4 2:00
-5:00 US E%sT
#
# Perry County, Indiana, switched from eastern to central time in April 2006.
+# From Alois Triendl (2019-07-09):
+# The Indianapolis News, Friday 27 October 1967 states that Perry County
+# returned to CST. It went again to EST on 27 April 1969, as documented by the
+# Indianapolis star of Saturday 26 April.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
-Rule Perry 1946 only - Apr lastSun 2:00 1:00 D
-Rule Perry 1946 only - Sep lastSun 2:00 0 S
-Rule Perry 1953 1954 - Apr lastSun 2:00 1:00 D
-Rule Perry 1953 1959 - Sep lastSun 2:00 0 S
Rule Perry 1955 only - May 1 0:00 1:00 D
+Rule Perry 1955 1960 - Sep lastSun 2:00 0 S
Rule Perry 1956 1963 - Apr lastSun 2:00 1:00 D
-Rule Perry 1960 only - Oct lastSun 2:00 0 S
-Rule Perry 1961 only - Sep lastSun 2:00 0 S
-Rule Perry 1962 1963 - Oct lastSun 2:00 0 S
+Rule Perry 1961 1963 - Oct lastSun 2:00 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Indiana/Tell_City -5:47:03 - LMT 1883 Nov 18 12:12:57
-6:00 US C%sT 1946
-6:00 Perry C%sT 1964 Apr 26 2:00
- -5:00 - EST 1969
+ -5:00 - EST 1967 Oct 29 2:00
+ -6:00 US C%sT 1969 Apr 27 2:00
-5:00 US E%sT 1971
-5:00 - EST 2006 Apr 2 2:00
-6:00 US C%sT
#
# Pike County, Indiana moved from central to eastern time in 1977,
# then switched back in 2006, then switched back again in 2007.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
Rule Pike 1955 only - May 1 0:00 1:00 D
Rule Pike 1955 1960 - Sep lastSun 2:00 0 S
Rule Pike 1956 1964 - Apr lastSun 2:00 1:00 D
Rule Pike 1961 1964 - Oct lastSun 2:00 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Indiana/Petersburg -5:49:07 - LMT 1883 Nov 18 12:10:53
-6:00 US C%sT 1955
-6:00 Pike C%sT 1965 Apr 25 2:00
-5:00 - EST 1966 Oct 30 2:00
-6:00 US C%sT 1977 Oct 30 2:00
-5:00 - EST 2006 Apr 2 2:00
-6:00 US C%sT 2007 Nov 4 2:00
-5:00 US E%sT
#
# Starke County, Indiana moved from central to eastern time in 1991,
# then switched back in 2006.
# From Arthur David Olson (1991-10-28):
# An article on page A3 of the Sunday, 1991-10-27 Washington Post
# notes that Starke County switched from Central time to Eastern time as of
# 1991-10-27.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
Rule Starke 1947 1961 - Apr lastSun 2:00 1:00 D
Rule Starke 1947 1954 - Sep lastSun 2:00 0 S
Rule Starke 1955 1956 - Oct lastSun 2:00 0 S
Rule Starke 1957 1958 - Sep lastSun 2:00 0 S
Rule Starke 1959 1961 - Oct lastSun 2:00 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Indiana/Knox -5:46:30 - LMT 1883 Nov 18 12:13:30
-6:00 US C%sT 1947
-6:00 Starke C%sT 1962 Apr 29 2:00
-5:00 - EST 1963 Oct 27 2:00
-6:00 US C%sT 1991 Oct 27 2:00
-5:00 - EST 2006 Apr 2 2:00
-6:00 US C%sT
#
# Pulaski County, Indiana, switched from eastern to central time in
# April 2006 and then switched back in March 2007.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
Rule Pulaski 1946 1960 - Apr lastSun 2:00 1:00 D
Rule Pulaski 1946 1954 - Sep lastSun 2:00 0 S
Rule Pulaski 1955 1956 - Oct lastSun 2:00 0 S
Rule Pulaski 1957 1960 - Sep lastSun 2:00 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Indiana/Winamac -5:46:25 - LMT 1883 Nov 18 12:13:35
-6:00 US C%sT 1946
-6:00 Pulaski C%sT 1961 Apr 30 2:00
-5:00 - EST 1969
-5:00 US E%sT 1971
-5:00 - EST 2006 Apr 2 2:00
-6:00 US C%sT 2007 Mar 11 2:00
-5:00 US E%sT
#
# Switzerland County, Indiana, did not observe DST from 1973 through 2005.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Indiana/Vevay -5:40:16 - LMT 1883 Nov 18 12:19:44
-6:00 US C%sT 1954 Apr 25 2:00
-5:00 - EST 1969
-5:00 US E%sT 1973
-5:00 - EST 2006
-5:00 US E%sT
# From Paul Eggert (2018-03-20):
# The Louisville & Nashville Railroad's 1883-11-18 change occurred at
# 10:00 old local time; train were supposed to come to a standstill
# for precisely 18 minutes. See Bartky Fig. 1 (page 50). It is not
# clear how this matched civil time in Louisville, so for now continue
# to assume Louisville switched at noon new local time, like New York.
#
+# From Michael Deckers (2019-08-06):
+# From the contemporary source given by Alois Treindl,
+# the switch in Louisville on 1946-04-28 was on 00:01
+# From Paul Eggert (2019-08-26):
+# That source was the Louisville Courier-Journal, 1946-04-27, p 4.
+# Shanks gives 02:00 for all 20th-century transition times in Louisville.
+# Evidently this is wrong for spring 1946. Although also likely wrong
+# for other dates, we have no data.
+#
# Part of Kentucky left its clocks alone in 1974.
# This also includes Clark, Floyd, and Harrison counties in Indiana.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
Rule Louisville 1921 only - May 1 2:00 1:00 D
Rule Louisville 1921 only - Sep 1 2:00 0 S
-Rule Louisville 1941 1961 - Apr lastSun 2:00 1:00 D
+Rule Louisville 1941 only - Apr lastSun 2:00 1:00 D
Rule Louisville 1941 only - Sep lastSun 2:00 0 S
+Rule Louisville 1946 only - Apr lastSun 0:01 1:00 D
Rule Louisville 1946 only - Jun 2 2:00 0 S
+Rule Louisville 1950 1961 - Apr lastSun 2:00 1:00 D
Rule Louisville 1950 1955 - Sep lastSun 2:00 0 S
-Rule Louisville 1956 1960 - Oct lastSun 2:00 0 S
+Rule Louisville 1956 1961 - Oct lastSun 2:00 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Kentucky/Louisville -5:43:02 - LMT 1883 Nov 18 12:16:58
-6:00 US C%sT 1921
-6:00 Louisville C%sT 1942
-6:00 US C%sT 1946
-6:00 Louisville C%sT 1961 Jul 23 2:00
-5:00 - EST 1968
-5:00 US E%sT 1974 Jan 6 2:00
-6:00 1:00 CDT 1974 Oct 27 2:00
-5:00 US E%sT
#
# Wayne County, Kentucky
#
# From Lake Cumberland LIFE
# http://www.lake-cumberland.com/life/archive/news990129time.shtml
# (1999-01-29) via WKYM-101.7:
# Clinton County has joined Wayne County in asking the DoT to change from
# the Central to the Eastern time zone.... The Wayne County government made
# the same request in December. And while Russell County officials have not
# taken action, the majority of respondents to a poll conducted there in
# August indicated they would like to change to "fast time" also.
# The three Lake Cumberland counties are the farthest east of any U.S.
# location in the Central time zone.
#
# From Rich Wales (2000-08-29):
# After prolonged debate, and despite continuing deep differences of opinion,
# Wayne County (central Kentucky) is switching from Central (-0600) to Eastern
# (-0500) time. They won't "fall back" this year. See Sara Shipley,
# The difference an hour makes, Nando Times (2000-08-29 15:33 -0400).
#
# From Paul Eggert (2001-07-16):
# The final rule was published in the
# Federal Register 65, 160 (2000-08-17), pp 50154-50158.
# https://www.gpo.gov/fdsys/pkg/FR-2000-08-17/html/00-20854.htm
#
Zone America/Kentucky/Monticello -5:39:24 - LMT 1883 Nov 18 12:20:36
-6:00 US C%sT 1946
-6:00 - CST 1968
-6:00 US C%sT 2000 Oct 29 2:00
-5:00 US E%sT
# From Rives McDow (2000-08-30):
# Here ... are all the changes in the US since 1985.
# Kearny County, KS (put all of county on central;
# previously split between MST and CST) ... 1990-10
# Starke County, IN (from CST to EST) ... 1991-10
# Oliver County, ND (from MST to CST) ... 1992-10
# West Wendover, NV (from PST TO MST) ... 1999-10
# Wayne County, KY (from CST to EST) ... 2000-10
#
# From Paul Eggert (2001-07-17):
# We don't know where the line used to be within Kearny County, KS,
# so omit that change for now.
# See America/Indiana/Knox for the Starke County, IN change.
# See America/North_Dakota/Center for the Oliver County, ND change.
# West Wendover, NV officially switched from Pacific to mountain time on
# 1999-10-31. See the
# Federal Register 64, 203 (1999-10-21), pp 56705-56707.
# https://www.gpo.gov/fdsys/pkg/FR-1999-10-21/html/99-27240.htm
# However, the Federal Register says that West Wendover already operated
# on mountain time, and the rule merely made this official;
# hence a separate tz entry is not needed.
# Michigan
#
# From Bob Devine (1988-01-28):
# Michigan didn't observe DST from 1968 to 1973.
#
# From Paul Eggert (1999-03-31):
# Shanks writes that Michigan started using standard time on 1885-09-18,
# but Howse writes (pp 124-125, referring to Popular Astronomy, 1901-01)
# that Detroit kept
#
# local time until 1900 when the City Council decreed that clocks should
# be put back twenty-eight minutes to Central Standard Time. Half the
# city obeyed, half refused. After considerable debate, the decision
# was rescinded and the city reverted to Sun time. A derisive offer to
# erect a sundial in front of the city hall was referred to the
# Committee on Sewers. Then, in 1905, Central time was adopted
# by city vote.
#
# This story is too entertaining to be false, so go with Howse over Shanks.
#
# From Paul Eggert (2001-03-06):
# Garland (1927) writes "Cleveland and Detroit advanced their clocks
# one hour in 1914." This change is not in Shanks. We have no more
# info, so omit this for now.
#
-# From Paul Eggert (2017-07-26):
-# Although Shanks says Detroit observed DST in 1967 from 06-14 00:01
-# until 10-29 00:01, I now see multiple reports that this is incorrect.
-# For example, according to a 50-year anniversary report about the 1967
-# Detroit riots and a major-league doubleheader on 1967-07-23, "By the time
-# the last fly ball of the doubleheader settled into the glove of leftfielder
-# Lenny Green, it was after 7 p.m. Detroit did not observe daylight saving
-# time, so light was already starting to fail. Twilight was made even deeper
-# by billowing columns of smoke that ascended in an unbroken wall north of the
-# ballpark." See: Dow B. Detroit '67: As violence unfolded, Tigers played two
-# at home vs. Yankees. Detroit Free Press 2017-07-23.
-# https://www.freep.com/story/sports/mlb/tigers/2017/07/23/detroit-tigers-1967-riot-new-york-yankees/499951001/
+# From Paul Eggert (2019-07-06):
+# Due to a complicated set of legal maneuvers, in 1967 Michigan did
+# not start daylight saving time when the rest of the US did.
+# Instead, it began DST on Jun 14 at 00:01. This was big news:
+# the Detroit Free Press reported it at the top of Page 1 on
+# 1967-06-14, in an article "State Adjusting to Switch to Fast Time"
+# by Gary Blonston, above an article about Thurgood Marshall's
+# confirmation to the US Supreme Court. Although Shanks says Detroit
+# observed DST until 1967-10-29 00:01, that time of day seems to be
+# incorrect, as the Free Press later said DST ended in Michigan at the
+# same time as the rest of the US. Also, although Shanks reports no DST in
+# Detroit in 1968, it did observe DST that year; in the November 1968
+# election Michigan voters narrowly repealed DST, effective 1969.
#
# Most of Michigan observed DST from 1973 on, but was a bit late in 1975.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
Rule Detroit 1948 only - Apr lastSun 2:00 1:00 D
Rule Detroit 1948 only - Sep lastSun 2:00 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Detroit -5:32:11 - LMT 1905
-6:00 - CST 1915 May 15 2:00
-5:00 - EST 1942
-5:00 US E%sT 1946
- -5:00 Detroit E%sT 1973
+ -5:00 Detroit E%sT 1967 Jun 14 0:01
+ -5:00 US E%sT 1969
+ -5:00 - EST 1973
-5:00 US E%sT 1975
-5:00 - EST 1975 Apr 27 2:00
-5:00 US E%sT
#
# Dickinson, Gogebic, Iron, and Menominee Counties, Michigan,
# switched from EST to CST/CDT in 1973.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER
Rule Menominee 1946 only - Apr lastSun 2:00 1:00 D
Rule Menominee 1946 only - Sep lastSun 2:00 0 S
Rule Menominee 1966 only - Apr lastSun 2:00 1:00 D
Rule Menominee 1966 only - Oct lastSun 2:00 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Menominee -5:50:27 - LMT 1885 Sep 18 12:00
-6:00 US C%sT 1946
-6:00 Menominee C%sT 1969 Apr 27 2:00
-5:00 - EST 1973 Apr 29 2:00
-6:00 US C%sT
# Navassa
# administered by the US Fish and Wildlife Service
# claimed by US under the provisions of the 1856 Guano Islands Act
# also claimed by Haiti
# occupied 1857/1900 by the Navassa Phosphate Co
# US lighthouse 1917/1996-09
# currently uninhabited
# see Mark Fineman, "An Isle Rich in Guano and Discord",
# _Los Angeles Times_ (1998-11-10), A1, A10; it cites
# Jimmy Skaggs, _The Great Guano Rush_ (1994).
################################################################################
# From Paul Eggert (2017-02-10):
#
# Unless otherwise specified, the source for data through 1990 is:
# Thomas G. Shanks and Rique Pottenger, The International Atlas (6th edition),
# San Diego: ACS Publications, Inc. (2003).
# Unfortunately this book contains many errors and cites no sources.
#
# Many years ago Gwillim Law wrote that a good source
# for time zone data was the International Air Transport
# Association's Standard Schedules Information Manual (IATA SSIM),
# published semiannually. Law sent in several helpful summaries
# of the IATA's data after 1990. Except where otherwise noted,
# IATA SSIM is the source for entries after 1990.
#
# Other sources occasionally used include:
#
+# Milne J. Civil time. Geogr J. 1899 Feb;13(2):173-94
+# <https://www.jstor.org/stable/1774359>.
+#
+# Pearce C. The Great Daylight Saving Time Controversy.
+# Australian Ebook Publisher. 2017. ISBN 978-1-925516-96-8.
+#
# Edward W. Whitman, World Time Differences,
# Whitman Publishing Co, 2 Niagara Av, Ealing, London (undated),
# which I found in the UCLA library.
#
# William Willett, The Waste of Daylight, 19th edition
# <http://cs.ucla.edu/~eggert/The-Waste-of-Daylight-19th.pdf>
# [PDF] (1914-03)
#
-# Milne J. Civil time. Geogr J. 1899 Feb;13(2):173-94
-# <https://www.jstor.org/stable/1774359>.
-#
# See the 'europe' file for Greenland.
# Canada
# From Alain LaBonté (1994-11-14):
# I post here the time zone abbreviations standardized in Canada
# for both English and French in the CAN/CSA-Z234.4-89 standard....
#
# UTC Standard time Daylight saving time
# offset French English French English
# -2:30 - - HAT NDT
# -3 - - HAA ADT
# -3:30 HNT NST - -
# -4 HNA AST HAE EDT
# -5 HNE EST HAC CDT
# -6 HNC CST HAR MDT
# -7 HNR MST HAP PDT
# -8 HNP PST HAY YDT
# -9 HNY YST - -
#
# HN: Heure Normale ST: Standard Time
# HA: Heure Avancée DT: Daylight saving Time
#
# A: de l'Atlantique Atlantic
# C: du Centre Central
# E: de l'Est Eastern
# M: Mountain
# N: Newfoundland
# P: du Pacifique Pacific
# R: des Rocheuses
# T: de Terre-Neuve
# Y: du Yukon Yukon
#
# From Paul Eggert (1994-11-22):
# Alas, this sort of thing must be handled by localization software.
# Unless otherwise specified, the data entries for Canada are all from Shanks
# & Pottenger.
# From Chris Walton (2006-04-01, 2006-04-25, 2006-06-26, 2007-01-31,
# 2007-03-01):
# The British Columbia government announced yesterday that it will
# adjust daylight savings next year to align with changes in the
# U.S. and the rest of Canada....
# https://archive.news.gov.bc.ca/releases/news_releases_2005-2009/2006AG0014-000330.htm
# ...
# Nova Scotia
# Daylight saving time will be extended by four weeks starting in 2007....
# https://www.novascotia.ca/just/regulations/rg2/2006/ma1206.pdf
#
# [For New Brunswick] the new legislation dictates that the time change is to
# be done at 02:00 instead of 00:01.
# https://www.gnb.ca/0062/acts/BBA-2006/Chap-19.pdf
# ...
# Manitoba has traditionally changed the clock every fall at 03:00.
# As of 2006, the transition is to take place one hour earlier at 02:00.
# https://web2.gov.mb.ca/laws/statutes/ccsm/o030e.php
# ...
# [Alberta, Ontario, Quebec] will follow US rules.
# http://www.qp.gov.ab.ca/documents/spring/CH03_06.CFM
# http://www.e-laws.gov.on.ca/DBLaws/Source/Regs/English/2006/R06111_e.htm
# http://www2.publicationsduquebec.gouv.qc.ca/dynamicSearch/telecharge.php?type=5&file=2006C39A.PDF
# ...
# P.E.I. will follow US rules....
# http://www.assembly.pe.ca/bills/pdf_chapter/62/3/chapter-41.pdf
# ...
# Province of Newfoundland and Labrador....
# http://www.hoa.gov.nl.ca/hoa/bills/Bill0634.htm
# ...
# Yukon
# https://www.gov.yk.ca/legislation/regs/oic2006_127.pdf
# ...
# N.W.T. will follow US rules. Whoever maintains the government web site
# does not seem to believe in bookmarks. To see the news release, click the
# following link and search for "Daylight Savings Time Change". Press the
# "Daylight Savings Time Change" link; it will fire off a popup using
# JavaScript.
# http://www.exec.gov.nt.ca/currentnews/currentPR.asp?mode=archive
# ...
# Nunavut
# An amendment to the Interpretation Act was registered on February 19/2007....
# http://action.attavik.ca/home/justice-gn/attach/2007/gaz02part2.pdf
# From Paul Eggert (2014-10-18):
# H. David Matthews and Mary Vincent's map
# "It's about TIME", _Canadian Geographic_ (September-October 1998)
# http://www.canadiangeographic.ca/Magazine/SO98/alacarte.asp
# contains detailed boundaries for regions observing nonstandard
# time and daylight saving time arrangements in Canada circa 1998.
#
# National Research Council Canada maintains info about time zones and DST.
# https://www.nrc-cnrc.gc.ca/eng/services/time/time_zones.html
# https://www.nrc-cnrc.gc.ca/eng/services/time/faq/index.html#Q5
# Its unofficial information is often taken from Matthews and Vincent.
# From Paul Eggert (2006-06-27):
# For now, assume all of DST-observing Canada will fall into line with the
# new US DST rules,
# From Chris Walton (2011-12-01)
# In the first of Tammy Hardwick's articles
# http://www.ilovecreston.com/?p=articles&t=spec&ar=260
# she quotes the Friday November 1/1918 edition of the Creston Review.
# The quote includes these two statements:
# 'Sunday the CPR went back to the old system of time...'
# '... The daylight saving scheme was dropped all over Canada at the same time,'
# These statements refer to a transition from daylight time to standard time
# that occurred nationally on Sunday October 27/1918. This transition was
# also documented in the Saturday October 26/1918 edition of the Toronto Star.
# In light of that evidence, we alter the date from the earlier believed
# Oct 31, to Oct 27, 1918 (and Sunday is a more likely transition day
# than Thursday) in all Canadian rulesets.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Canada 1918 only - Apr 14 2:00 1:00 D
Rule Canada 1918 only - Oct 27 2:00 0 S
Rule Canada 1942 only - Feb 9 2:00 1:00 W # War
Rule Canada 1945 only - Aug 14 23:00u 1:00 P # Peace
Rule Canada 1945 only - Sep 30 2:00 0 S
Rule Canada 1974 1986 - Apr lastSun 2:00 1:00 D
Rule Canada 1974 2006 - Oct lastSun 2:00 0 S
Rule Canada 1987 2006 - Apr Sun>=1 2:00 1:00 D
Rule Canada 2007 max - Mar Sun>=8 2:00 1:00 D
Rule Canada 2007 max - Nov Sun>=1 2:00 0 S
# Newfoundland and Labrador
# From Paul Eggert (2017-10-14):
# Legally Labrador should observe Newfoundland time; see:
# McLeod J. Labrador time - legal or not? St. John's Telegram, 2017-10-07
# http://www.thetelegram.com/news/local/labrador-time--legal-or-not-154860/
# Matthews and Vincent (1998) write that the only part of Labrador
# that follows the rules is the southeast corner, including Port Hope
# Simpson and Mary's Harbour, but excluding, say, Black Tickle.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule StJohns 1917 only - Apr 8 2:00 1:00 D
Rule StJohns 1917 only - Sep 17 2:00 0 S
# Whitman gives 1919 Apr 5 and 1920 Apr 5; go with Shanks & Pottenger.
Rule StJohns 1919 only - May 5 23:00 1:00 D
Rule StJohns 1919 only - Aug 12 23:00 0 S
# For 1931-1935 Whitman gives Apr same date; go with Shanks & Pottenger.
Rule StJohns 1920 1935 - May Sun>=1 23:00 1:00 D
Rule StJohns 1920 1935 - Oct lastSun 23:00 0 S
# For 1936-1941 Whitman gives May Sun>=8 and Oct Sun>=1; go with Shanks &
# Pottenger.
Rule StJohns 1936 1941 - May Mon>=9 0:00 1:00 D
Rule StJohns 1936 1941 - Oct Mon>=2 0:00 0 S
# Whitman gives the following transitions:
# 1942 03-01/12-31, 1943 05-30/09-05, 1944 07-10/09-02, 1945 01-01/10-07
# but go with Shanks & Pottenger and assume they used Canadian rules.
# For 1946-9 Whitman gives May 5,4,9,1 - Oct 1,5,3,2, and for 1950 he gives
# Apr 30 - Sep 24; go with Shanks & Pottenger.
Rule StJohns 1946 1950 - May Sun>=8 2:00 1:00 D
Rule StJohns 1946 1950 - Oct Sun>=2 2:00 0 S
Rule StJohns 1951 1986 - Apr lastSun 2:00 1:00 D
Rule StJohns 1951 1959 - Sep lastSun 2:00 0 S
Rule StJohns 1960 1986 - Oct lastSun 2:00 0 S
# From Paul Eggert (2000-10-02):
# INMS (2000-09-12) says that, since 1988 at least, Newfoundland switches
# at 00:01 local time. For now, assume it started in 1987.
# From Michael Pelley (2011-09-12):
# We received today, Monday, September 12, 2011, notification that the
# changes to the Newfoundland Standard Time Act have been proclaimed.
# The change in the Act stipulates that the change from Daylight Savings
# Time to Standard Time and from Standard Time to Daylight Savings Time
# now occurs at 2:00AM.
# ...
# http://www.assembly.nl.ca/legislation/sr/annualstatutes/2011/1106.chp.htm
# ...
# MICHAEL PELLEY | Manager of Enterprise Architecture - Solution Delivery
# Office of the Chief Information Officer
# Executive Council
# Government of Newfoundland & Labrador
Rule StJohns 1987 only - Apr Sun>=1 0:01 1:00 D
Rule StJohns 1987 2006 - Oct lastSun 0:01 0 S
Rule StJohns 1988 only - Apr Sun>=1 0:01 2:00 DD
Rule StJohns 1989 2006 - Apr Sun>=1 0:01 1:00 D
Rule StJohns 2007 2011 - Mar Sun>=8 0:01 1:00 D
Rule StJohns 2007 2010 - Nov Sun>=1 0:01 0 S
#
# St John's has an apostrophe, but Posix file names can't have apostrophes.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/St_Johns -3:30:52 - LMT 1884
-3:30:52 StJohns N%sT 1918
-3:30:52 Canada N%sT 1919
-3:30:52 StJohns N%sT 1935 Mar 30
-3:30 StJohns N%sT 1942 May 11
-3:30 Canada N%sT 1946
-3:30 StJohns N%sT 2011 Nov
-3:30 Canada N%sT
# most of east Labrador
# The name 'Happy Valley-Goose Bay' is too long; use 'Goose Bay'.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Goose_Bay -4:01:40 - LMT 1884 # Happy Valley-Goose Bay
-3:30:52 - NST 1918
-3:30:52 Canada N%sT 1919
-3:30:52 - NST 1935 Mar 30
-3:30 - NST 1936
-3:30 StJohns N%sT 1942 May 11
-3:30 Canada N%sT 1946
-3:30 StJohns N%sT 1966 Mar 15 2:00
-4:00 StJohns A%sT 2011 Nov
-4:00 Canada A%sT
# west Labrador, Nova Scotia, Prince Edward I
# From Brian Inglis (2015-07-20):
# From the historical weather station records available at:
# https://weatherspark.com/history/28351/1971/Sydney-Nova-Scotia-Canada
# Sydney shares the same time history as Glace Bay, so was
# likely to be the same across the island....
# Sydney, as the capital and most populous location, or Cape Breton, would
# have been better names for the zone had we known this in 1996.
# From Paul Eggert (2015-07-20):
# Shanks & Pottenger write that since 1970 most of this region has been like
# Halifax. Many locales did not observe peacetime DST until 1972;
# the Cape Breton area, represented by Glace Bay, is the largest we know of
# (Glace Bay was perhaps not the best name choice but no point changing now).
# Shanks & Pottenger also write that Liverpool, NS was the only town
# in Canada to observe DST in 1971 but not 1970; for now we'll assume
# this is a typo.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Halifax 1916 only - Apr 1 0:00 1:00 D
Rule Halifax 1916 only - Oct 1 0:00 0 S
Rule Halifax 1920 only - May 9 0:00 1:00 D
Rule Halifax 1920 only - Aug 29 0:00 0 S
Rule Halifax 1921 only - May 6 0:00 1:00 D
Rule Halifax 1921 1922 - Sep 5 0:00 0 S
Rule Halifax 1922 only - Apr 30 0:00 1:00 D
Rule Halifax 1923 1925 - May Sun>=1 0:00 1:00 D
Rule Halifax 1923 only - Sep 4 0:00 0 S
Rule Halifax 1924 only - Sep 15 0:00 0 S
Rule Halifax 1925 only - Sep 28 0:00 0 S
Rule Halifax 1926 only - May 16 0:00 1:00 D
Rule Halifax 1926 only - Sep 13 0:00 0 S
Rule Halifax 1927 only - May 1 0:00 1:00 D
Rule Halifax 1927 only - Sep 26 0:00 0 S
Rule Halifax 1928 1931 - May Sun>=8 0:00 1:00 D
Rule Halifax 1928 only - Sep 9 0:00 0 S
Rule Halifax 1929 only - Sep 3 0:00 0 S
Rule Halifax 1930 only - Sep 15 0:00 0 S
Rule Halifax 1931 1932 - Sep Mon>=24 0:00 0 S
Rule Halifax 1932 only - May 1 0:00 1:00 D
Rule Halifax 1933 only - Apr 30 0:00 1:00 D
Rule Halifax 1933 only - Oct 2 0:00 0 S
Rule Halifax 1934 only - May 20 0:00 1:00 D
Rule Halifax 1934 only - Sep 16 0:00 0 S
Rule Halifax 1935 only - Jun 2 0:00 1:00 D
Rule Halifax 1935 only - Sep 30 0:00 0 S
Rule Halifax 1936 only - Jun 1 0:00 1:00 D
Rule Halifax 1936 only - Sep 14 0:00 0 S
Rule Halifax 1937 1938 - May Sun>=1 0:00 1:00 D
Rule Halifax 1937 1941 - Sep Mon>=24 0:00 0 S
Rule Halifax 1939 only - May 28 0:00 1:00 D
Rule Halifax 1940 1941 - May Sun>=1 0:00 1:00 D
Rule Halifax 1946 1949 - Apr lastSun 2:00 1:00 D
Rule Halifax 1946 1949 - Sep lastSun 2:00 0 S
Rule Halifax 1951 1954 - Apr lastSun 2:00 1:00 D
Rule Halifax 1951 1954 - Sep lastSun 2:00 0 S
Rule Halifax 1956 1959 - Apr lastSun 2:00 1:00 D
Rule Halifax 1956 1959 - Sep lastSun 2:00 0 S
Rule Halifax 1962 1973 - Apr lastSun 2:00 1:00 D
Rule Halifax 1962 1973 - Oct lastSun 2:00 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Halifax -4:14:24 - LMT 1902 Jun 15
-4:00 Halifax A%sT 1918
-4:00 Canada A%sT 1919
-4:00 Halifax A%sT 1942 Feb 9 2:00s
-4:00 Canada A%sT 1946
-4:00 Halifax A%sT 1974
-4:00 Canada A%sT
Zone America/Glace_Bay -3:59:48 - LMT 1902 Jun 15
-4:00 Canada A%sT 1953
-4:00 Halifax A%sT 1954
-4:00 - AST 1972
-4:00 Halifax A%sT 1974
-4:00 Canada A%sT
# New Brunswick
# From Paul Eggert (2007-01-31):
# The Time Definition Act <http://www.gnb.ca/0062/PDF-acts/t-06.pdf>
# says they changed at 00:01 through 2006, and
# <http://www.canlii.org/nb/laws/sta/t-6/20030127/whole.html> makes it
# clear that this was the case since at least 1993.
# For now, assume it started in 1993.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Moncton 1933 1935 - Jun Sun>=8 1:00 1:00 D
Rule Moncton 1933 1935 - Sep Sun>=8 1:00 0 S
Rule Moncton 1936 1938 - Jun Sun>=1 1:00 1:00 D
Rule Moncton 1936 1938 - Sep Sun>=1 1:00 0 S
Rule Moncton 1939 only - May 27 1:00 1:00 D
Rule Moncton 1939 1941 - Sep Sat>=21 1:00 0 S
Rule Moncton 1940 only - May 19 1:00 1:00 D
Rule Moncton 1941 only - May 4 1:00 1:00 D
Rule Moncton 1946 1972 - Apr lastSun 2:00 1:00 D
Rule Moncton 1946 1956 - Sep lastSun 2:00 0 S
Rule Moncton 1957 1972 - Oct lastSun 2:00 0 S
Rule Moncton 1993 2006 - Apr Sun>=1 0:01 1:00 D
Rule Moncton 1993 2006 - Oct lastSun 0:01 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Moncton -4:19:08 - LMT 1883 Dec 9
-5:00 - EST 1902 Jun 15
-4:00 Canada A%sT 1933
-4:00 Moncton A%sT 1942
-4:00 Canada A%sT 1946
-4:00 Moncton A%sT 1973
-4:00 Canada A%sT 1993
-4:00 Moncton A%sT 2007
-4:00 Canada A%sT
# Quebec
# From Paul Eggert (2015-03-24):
# See America/Toronto for most of Quebec, including Montreal.
#
# Matthews and Vincent (1998) also write that Quebec east of the -63
# meridian is supposed to observe AST, but residents as far east as
# Natashquan use EST/EDT, and residents east of Natashquan use AST.
# The Quebec department of justice writes in
# "The situation in Minganie and Basse-Côte-Nord"
# http://www.justice.gouv.qc.ca/english/publications/generale/temps-minganie-a.htm
# that the coastal strip from just east of Natashquan to Blanc-Sablon
# observes Atlantic standard time all year round.
# https://www.assnat.qc.ca/Media/Process.aspx?MediaId=ANQ.Vigie.Bll.DocumentGenerique_8845en
# says this common practice was codified into law as of 2007.
# For lack of better info, guess this practice began around 1970, contra to
# Shanks & Pottenger who have this region observing AST/ADT.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Blanc-Sablon -3:48:28 - LMT 1884
-4:00 Canada A%sT 1970
-4:00 - AST
# Ontario
# From Paul Eggert (2006-07-09):
# Shanks & Pottenger write that since 1970 most of Ontario has been like
# Toronto.
# Thunder Bay skipped DST in 1973.
# Many smaller locales did not observe peacetime DST until 1974;
# Nipigon (EST) and Rainy River (CST) are the largest that we know of.
# Far west Ontario is like Winnipeg; far east Quebec is like Halifax.
# From Mark Brader (2003-07-26):
# [According to the Toronto Star] Orillia, Ontario, adopted DST
# effective Saturday, 1912-06-22, 22:00; the article mentions that
# Port Arthur (now part of Thunder Bay, Ontario) as well as Moose Jaw
# have already done so. In Orillia DST was to run until Saturday,
# 1912-08-31 (no time mentioned), but it was met with considerable
# hostility from certain segments of the public, and was revoked after
# only two weeks - I copied it as Saturday, 1912-07-07, 22:00, but
# presumably that should be -07-06. (1912-06-19, -07-12; also letters
# earlier in June).
#
# Kenora, Ontario, was to abandon DST on 1914-06-01 (-05-21).
#
# From Paul Eggert (2017-07-08):
# For more on Orillia, see: Daubs K. Bold attempt at daylight saving
# time became a comic failure in Orillia. Toronto Star 2017-07-08.
# https://www.thestar.com/news/insight/2017/07/08/bold-attempt-at-daylight-saving-time-became-a-comic-failure-in-orillia.html
# From Paul Eggert (1997-10-17):
# Mark Brader writes that an article in the 1997-10-14 Toronto Star
# says that Atikokan, Ontario currently does not observe DST,
# but will vote on 11-10 whether to use EST/EDT.
# He also writes that the Ontario Time Act (1990, Chapter T.9)
# http://www.gov.on.ca/MBS/english/publications/statregs/conttext.html
# says that Ontario east of 90W uses EST/EDT, and west of 90W uses CST/CDT.
# Officially Atikokan is therefore on CST/CDT, and most likely this report
# concerns a non-official time observed as a matter of local practice.
#
# From Paul Eggert (2000-10-02):
# Matthews and Vincent (1998) write that Atikokan, Pickle Lake, and
# New Osnaburgh observe CST all year, that Big Trout Lake observes
# CST/CDT, and that Upsala and Shebandowan observe EST/EDT, all in
# violation of the official Ontario rules.
#
# From Paul Eggert (2006-07-09):
# Chris Walton (2006-07-06) mentioned an article by Stephanie MacLellan in the
# 2005-07-21 Chronicle-Journal, which said:
#
# The clocks in Atikokan stay set on standard time year-round.
# This means they spend about half the time on central time and
# the other half on eastern time.
#
# For the most part, the system works, Mayor Dennis Brown said.
#
# "The majority of businesses in Atikokan deal more with Eastern
# Canada, but there are some that deal with Western Canada," he
# said. "I don't see any changes happening here."
#
# Walton also writes "Supposedly Pickle Lake and Mishkeegogamang
# [New Osnaburgh] follow the same practice."
# From Garry McKinnon (2006-07-14) via Chris Walton:
# I chatted with a member of my board who has an outstanding memory
# and a long history in Atikokan (and in the telecom industry) and he
# can say for certain that Atikokan has been practicing the current
# time keeping since 1952, at least.
# From Paul Eggert (2006-07-17):
# Shanks & Pottenger say that Atikokan has agreed with Rainy River
# ever since standard time was introduced, but the information from
# McKinnon sounds more authoritative. For now, assume that Atikokan
# switched to EST immediately after WWII era daylight saving time
# ended. This matches the old (less-populous) America/Coral_Harbour
# entry since our cutoff date of 1970, so we can move
# America/Coral_Harbour to the 'backward' file.
# From Mark Brader (2010-03-06):
#
# Currently the database has:
#
# # Ontario
#
# # From Paul Eggert (2006-07-09):
# # Shanks & Pottenger write that since 1970 most of Ontario has been like
# # Toronto.
# # Thunder Bay skipped DST in 1973.
# # Many smaller locales did not observe peacetime DST until 1974;
# # Nipigon (EST) and Rainy River (CST) are the largest that we know of.
#
# In the (Toronto) Globe and Mail for Saturday, 1955-09-24, in the bottom
# right corner of page 1, it says that Toronto will return to standard
# time at 2 am Sunday morning (which agrees with the database), and that:
#
# The one-hour setback will go into effect throughout most of Ontario,
# except in areas like Windsor which remains on standard time all year.
#
# Windsor is, of course, a lot larger than Nipigon.
#
# I only came across this incidentally. I don't know if Windsor began
# observing DST when Detroit did, or in 1974, or on some other date.
#
# By the way, the article continues by noting that:
#
# Some cities in the United States have pushed the deadline back
# three weeks and will change over from daylight saving in October.
# From Arthur David Olson (2010-07-17):
#
# "Standard Time and Time Zones in Canada" appeared in
# The Journal of The Royal Astronomical Society of Canada,
# volume 26, number 2 (February 1932) and, as of 2010-07-17,
# was available at
# http://adsabs.harvard.edu/full/1932JRASC..26...49S
#
# It includes the text below (starting on page 57):
#
# A list of the places in Canada using daylight saving time would
# require yearly revision. From information kindly furnished by
# the provincial governments and by the postmasters in many cities
# and towns, it is found that the following places used daylight sav-
# ing in 1930. The information for the province of Quebec is definite,
# for the other provinces only approximate:
#
# Province Daylight saving time used
# Prince Edward Island Not used.
# Nova Scotia In Halifax only.
# New Brunswick In St. John only.
# Quebec In the following places:
# Montreal Lachine
# Quebec Mont-Royal
# Lévis Iberville
# St. Lambert Cap de la Madelèine
# Verdun Loretteville
# Westmount Richmond
# Outremont St. Jérôme
# Longueuil Greenfield Park
# Arvida Waterloo
# Chambly-Canton Beaulieu
# Melbourne La Tuque
# St. Théophile Buckingham
# Ontario Used generally in the cities and towns along
# the southerly part of the province. Not
# used in the northwesterly part.
# Manitoba Not used.
# Saskatchewan In Regina only.
# Alberta Not used.
# British Columbia Not used.
#
# With some exceptions, the use of daylight saving may be said to be limited
# to those cities and towns lying between Quebec city and Windsor, Ont.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Toronto 1919 only - Mar 30 23:30 1:00 D
Rule Toronto 1919 only - Oct 26 0:00 0 S
Rule Toronto 1920 only - May 2 2:00 1:00 D
Rule Toronto 1920 only - Sep 26 0:00 0 S
Rule Toronto 1921 only - May 15 2:00 1:00 D
Rule Toronto 1921 only - Sep 15 2:00 0 S
Rule Toronto 1922 1923 - May Sun>=8 2:00 1:00 D
# Shanks & Pottenger say 1923-09-19; assume it's a typo and that "-16"
# was meant.
Rule Toronto 1922 1926 - Sep Sun>=15 2:00 0 S
Rule Toronto 1924 1927 - May Sun>=1 2:00 1:00 D
Rule Toronto 1927 1937 - Sep Sun>=25 2:00 0 S
Rule Toronto 1928 1937 - Apr Sun>=25 2:00 1:00 D
Rule Toronto 1938 1940 - Apr lastSun 2:00 1:00 D
Rule Toronto 1938 1939 - Sep lastSun 2:00 0 S
Rule Toronto 1945 1946 - Sep lastSun 2:00 0 S
Rule Toronto 1946 only - Apr lastSun 2:00 1:00 D
Rule Toronto 1947 1949 - Apr lastSun 0:00 1:00 D
Rule Toronto 1947 1948 - Sep lastSun 0:00 0 S
Rule Toronto 1949 only - Nov lastSun 0:00 0 S
Rule Toronto 1950 1973 - Apr lastSun 2:00 1:00 D
Rule Toronto 1950 only - Nov lastSun 2:00 0 S
Rule Toronto 1951 1956 - Sep lastSun 2:00 0 S
# Shanks & Pottenger say Toronto ended DST a week early in 1971,
# namely on 1971-10-24, but Mark Brader wrote (2003-05-31) that this
# is wrong, and that he had confirmed it by checking the 1971-10-30
# Toronto Star, which said that DST was ending 1971-10-31 as usual.
Rule Toronto 1957 1973 - Oct lastSun 2:00 0 S
# From Paul Eggert (2003-07-27):
# Willett (1914-03) writes (p. 17) "In the Cities of Fort William, and
# Port Arthur, Ontario, the principle of the Bill has been in
# operation for the past three years, and in the City of Moose Jaw,
# Saskatchewan, for one year."
# From David Bryan via Tory Tronrud, Director/Curator,
# Thunder Bay Museum (2003-11-12):
# There is some suggestion, however, that, by-law or not, daylight
# savings time was being practiced in Fort William and Port Arthur
# before 1909.... [I]n 1910, the line between the Eastern and Central
# Time Zones was permanently moved about two hundred miles west to
# include the Thunder Bay area.... When Canada adopted daylight
# savings time in 1916, Fort William and Port Arthur, having done so
# already, did not change their clocks.... During the Second World
# War,... [t]he cities agreed to implement DST during the summer
# months for the remainder of the war years.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Toronto -5:17:32 - LMT 1895
-5:00 Canada E%sT 1919
-5:00 Toronto E%sT 1942 Feb 9 2:00s
-5:00 Canada E%sT 1946
-5:00 Toronto E%sT 1974
-5:00 Canada E%sT
Zone America/Thunder_Bay -5:57:00 - LMT 1895
-6:00 - CST 1910
-5:00 - EST 1942
-5:00 Canada E%sT 1970
-5:00 Toronto E%sT 1973
-5:00 - EST 1974
-5:00 Canada E%sT
Zone America/Nipigon -5:53:04 - LMT 1895
-5:00 Canada E%sT 1940 Sep 29
-5:00 1:00 EDT 1942 Feb 9 2:00s
-5:00 Canada E%sT
Zone America/Rainy_River -6:18:16 - LMT 1895
-6:00 Canada C%sT 1940 Sep 29
-6:00 1:00 CDT 1942 Feb 9 2:00s
-6:00 Canada C%sT
Zone America/Atikokan -6:06:28 - LMT 1895
-6:00 Canada C%sT 1940 Sep 29
-6:00 1:00 CDT 1942 Feb 9 2:00s
-6:00 Canada C%sT 1945 Sep 30 2:00
-5:00 - EST
# Manitoba
# From Rob Douglas (2006-04-06):
# the old Manitoba Time Act - as amended by Bill 2, assented to
# March 27, 1987 ... said ...
# "between two o'clock Central Standard Time in the morning of
# the first Sunday of April of each year and two o'clock Central
# Standard Time in the morning of the last Sunday of October next
# following, one hour in advance of Central Standard Time."...
# I believe that the English legislation [of the old time act] had
# been assented to (March 22, 1967)....
# Also, as far as I can tell, there was no order-in-council varying
# the time of Daylight Saving Time for 2005 and so the provisions of
# the 1987 version would apply - the changeover was at 2:00 Central
# Standard Time (i.e. not until 3:00 Central Daylight Time).
# From Paul Eggert (2006-04-10):
# Shanks & Pottenger say Manitoba switched at 02:00 (not 02:00s)
# starting 1966. Since 02:00s is clearly correct for 1967 on, assume
# it was also 02:00s in 1966.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Winn 1916 only - Apr 23 0:00 1:00 D
Rule Winn 1916 only - Sep 17 0:00 0 S
Rule Winn 1918 only - Apr 14 2:00 1:00 D
Rule Winn 1918 only - Oct 27 2:00 0 S
Rule Winn 1937 only - May 16 2:00 1:00 D
Rule Winn 1937 only - Sep 26 2:00 0 S
Rule Winn 1942 only - Feb 9 2:00 1:00 W # War
Rule Winn 1945 only - Aug 14 23:00u 1:00 P # Peace
Rule Winn 1945 only - Sep lastSun 2:00 0 S
Rule Winn 1946 only - May 12 2:00 1:00 D
Rule Winn 1946 only - Oct 13 2:00 0 S
Rule Winn 1947 1949 - Apr lastSun 2:00 1:00 D
Rule Winn 1947 1949 - Sep lastSun 2:00 0 S
Rule Winn 1950 only - May 1 2:00 1:00 D
Rule Winn 1950 only - Sep 30 2:00 0 S
Rule Winn 1951 1960 - Apr lastSun 2:00 1:00 D
Rule Winn 1951 1958 - Sep lastSun 2:00 0 S
Rule Winn 1959 only - Oct lastSun 2:00 0 S
Rule Winn 1960 only - Sep lastSun 2:00 0 S
Rule Winn 1963 only - Apr lastSun 2:00 1:00 D
Rule Winn 1963 only - Sep 22 2:00 0 S
Rule Winn 1966 1986 - Apr lastSun 2:00s 1:00 D
Rule Winn 1966 2005 - Oct lastSun 2:00s 0 S
Rule Winn 1987 2005 - Apr Sun>=1 2:00s 1:00 D
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Winnipeg -6:28:36 - LMT 1887 Jul 16
-6:00 Winn C%sT 2006
-6:00 Canada C%sT
# Saskatchewan
# From Mark Brader (2003-07-26):
# The first actual adoption of DST in Canada was at the municipal
# level. As the [Toronto] Star put it (1912-06-07), "While people
# elsewhere have long been talking of legislation to save daylight,
# the city of Moose Jaw [Saskatchewan] has acted on its own hook."
# DST in Moose Jaw began on Saturday, 1912-06-01 (no time mentioned:
# presumably late evening, as below), and would run until "the end of
# the summer". The discrepancy between municipal time and railroad
# time was noted.
# From Paul Eggert (2003-07-27):
# Willett (1914-03) notes that DST "has been in operation ... in the
# City of Moose Jaw, Saskatchewan, for one year."
-# From Paul Eggert (2019-04-26):
-# Chris Pearce's book "The Great Daylight Saving Time Controversy" (2017)
-# says that Regina observed DST in 1914-1917. No dates and times,
+# From Paul Eggert (2019-07-25):
+# Pearce's book says Regina observed DST in 1914-1917. No dates and times,
# unfortunately. It also says that in 1914 Saskatoon observed DST
# from 1 June to 6 July, and that DST was also tried out in Davidson,
# Melfort, and Prince Albert.
# From Paul Eggert (2006-03-22):
# Shanks & Pottenger say that since 1970 this region has mostly been as Regina.
# Some western towns (e.g. Swift Current) switched from MST/MDT to CST in 1972.
# Other western towns (e.g. Lloydminster) are like Edmonton.
# Matthews and Vincent (1998) write that Denare Beach and Creighton
# are like Winnipeg, in violation of Saskatchewan law.
# From W. Jones (1992-11-06):
# The. . .below is based on information I got from our law library, the
# provincial archives, and the provincial Community Services department.
# A precise history would require digging through newspaper archives, and
# since you didn't say what you wanted, I didn't bother.
#
# Saskatchewan is split by a time zone meridian (105W) and over the years
# the boundary became pretty ragged as communities near it reevaluated
# their affiliations in one direction or the other. In 1965 a provincial
# referendum favoured legislating common time practices.
#
# On 15 April 1966 the Time Act (c. T-14, Revised Statutes of
# Saskatchewan 1978) was proclaimed, and established that the eastern
# part of Saskatchewan would use CST year round, that districts in
# northwest Saskatchewan would by default follow CST but could opt to
# follow Mountain Time rules (thus 1 hour difference in the winter and
# zero in the summer), and that districts in southwest Saskatchewan would
# by default follow MT but could opt to follow CST.
#
# It took a few years for the dust to settle (I know one story of a town
# on one time zone having its school in another, such that a mom had to
# serve her family lunch in two shifts), but presently it seems that only
# a few towns on the border with Alberta (e.g. Lloydminster) follow MT
# rules any more; all other districts appear to have used CST year round
# since sometime in the 1960s.
# From Chris Walton (2006-06-26):
# The Saskatchewan time act which was last updated in 1996 is about 30 pages
# long and rather painful to read.
# http://www.qp.gov.sk.ca/documents/English/Statutes/Statutes/T14.pdf
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Regina 1918 only - Apr 14 2:00 1:00 D
Rule Regina 1918 only - Oct 27 2:00 0 S
Rule Regina 1930 1934 - May Sun>=1 0:00 1:00 D
Rule Regina 1930 1934 - Oct Sun>=1 0:00 0 S
Rule Regina 1937 1941 - Apr Sun>=8 0:00 1:00 D
Rule Regina 1937 only - Oct Sun>=8 0:00 0 S
Rule Regina 1938 only - Oct Sun>=1 0:00 0 S
Rule Regina 1939 1941 - Oct Sun>=8 0:00 0 S
Rule Regina 1942 only - Feb 9 2:00 1:00 W # War
Rule Regina 1945 only - Aug 14 23:00u 1:00 P # Peace
Rule Regina 1945 only - Sep lastSun 2:00 0 S
Rule Regina 1946 only - Apr Sun>=8 2:00 1:00 D
Rule Regina 1946 only - Oct Sun>=8 2:00 0 S
Rule Regina 1947 1957 - Apr lastSun 2:00 1:00 D
Rule Regina 1947 1957 - Sep lastSun 2:00 0 S
Rule Regina 1959 only - Apr lastSun 2:00 1:00 D
Rule Regina 1959 only - Oct lastSun 2:00 0 S
#
Rule Swift 1957 only - Apr lastSun 2:00 1:00 D
Rule Swift 1957 only - Oct lastSun 2:00 0 S
Rule Swift 1959 1961 - Apr lastSun 2:00 1:00 D
Rule Swift 1959 only - Oct lastSun 2:00 0 S
Rule Swift 1960 1961 - Sep lastSun 2:00 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Regina -6:58:36 - LMT 1905 Sep
-7:00 Regina M%sT 1960 Apr lastSun 2:00
-6:00 - CST
Zone America/Swift_Current -7:11:20 - LMT 1905 Sep
-7:00 Canada M%sT 1946 Apr lastSun 2:00
-7:00 Regina M%sT 1950
-7:00 Swift M%sT 1972 Apr lastSun 2:00
-6:00 - CST
# Alberta
+# From Alois Triendl (2019-07-19):
+# There was no DST in Alberta in 1967... Calgary Herald, 29 April 1967.
+# 1969, no DST, from Edmonton Journal 18 April 1969
+#
+# From Paul Eggert (2019-07-25):
+# Pearce's book says that Alberta's 1948 Daylight Saving Act required
+# Mountain Standard Time without DST, and that "anyone who broke that law
+# could be fined up to $25 and costs". There seems to be no record of
+# anybody paying the fine. The law was not changed until an August 1971
+# plebiscite reinstituted DST in 1972. This story is also mentioned in:
+# Boyer JP. Forcing Choice: The Risky Reward of Referendums. Dundum. 2017.
+# ISBN 978-1459739123.
+
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Edm 1918 1919 - Apr Sun>=8 2:00 1:00 D
Rule Edm 1918 only - Oct 27 2:00 0 S
Rule Edm 1919 only - May 27 2:00 0 S
Rule Edm 1920 1923 - Apr lastSun 2:00 1:00 D
Rule Edm 1920 only - Oct lastSun 2:00 0 S
Rule Edm 1921 1923 - Sep lastSun 2:00 0 S
Rule Edm 1942 only - Feb 9 2:00 1:00 W # War
Rule Edm 1945 only - Aug 14 23:00u 1:00 P # Peace
Rule Edm 1945 only - Sep lastSun 2:00 0 S
Rule Edm 1947 only - Apr lastSun 2:00 1:00 D
Rule Edm 1947 only - Sep lastSun 2:00 0 S
-Rule Edm 1967 only - Apr lastSun 2:00 1:00 D
-Rule Edm 1967 only - Oct lastSun 2:00 0 S
-Rule Edm 1969 only - Apr lastSun 2:00 1:00 D
-Rule Edm 1969 only - Oct lastSun 2:00 0 S
Rule Edm 1972 1986 - Apr lastSun 2:00 1:00 D
Rule Edm 1972 2006 - Oct lastSun 2:00 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Edmonton -7:33:52 - LMT 1906 Sep
-7:00 Edm M%sT 1987
-7:00 Canada M%sT
# British Columbia
# From Paul Eggert (2006-03-22):
# Shanks & Pottenger write that since 1970 most of this region has
# been like Vancouver.
# Dawson Creek uses MST. Much of east BC is like Edmonton.
# Matthews and Vincent (1998) write that Creston is like Dawson Creek.
# It seems though that (re: Creston) is not entirely correct:
# From Chris Walton (2011-12-01):
# There are two areas within the Canadian province of British Columbia
# that do not currently observe daylight saving:
# a) The Creston Valley (includes the town of Creston and surrounding area)
# b) The eastern half of the Peace River Regional District
# (includes the cities of Dawson Creek and Fort St. John)
# Earlier this year I stumbled across a detailed article about the time
# keeping history of Creston; it was written by Tammy Hardwick who is the
# manager of the Creston & District Museum. The article was written in May 2009.
# http://www.ilovecreston.com/?p=articles&t=spec&ar=260
# According to the article, Creston has not changed its clocks since June 1918.
# i.e. Creston has been stuck on UT-7 for 93 years.
# Dawson Creek, on the other hand, changed its clocks as recently as April 1972.
# Unfortunately the exact date for the time change in June 1918 remains
# unknown and will be difficult to ascertain. I e-mailed Tammy a few months
# ago to ask if Sunday June 2 was a reasonable guess. She said it was just
# as plausible as any other date (in June). She also said that after writing
# the article she had discovered another time change in 1916; this is the
# subject of another article which she wrote in October 2010.
# http://www.creston.museum.bc.ca/index.php?module=comments&uop=view_comment&cm+id=56
# Here is a summary of the three clock change events in Creston's history:
# 1. 1884 or 1885: adoption of Mountain Standard Time (GMT-7)
# Exact date unknown
# 2. Oct 1916: switch to Pacific Standard Time (GMT-8)
# Exact date in October unknown; Sunday October 1 is a reasonable guess.
# 3. June 1918: switch to Pacific Daylight Time (GMT-7)
# Exact date in June unknown; Sunday June 2 is a reasonable guess.
# note 1:
# On Oct 27/1918 when daylight saving ended in the rest of Canada,
# Creston did not change its clocks.
# note 2:
# During WWII when the Federal Government legislated a mandatory clock change,
# Creston did not oblige.
# note 3:
# There is no guarantee that Creston will remain on Mountain Standard Time
# (UTC-7) forever.
# The subject was debated at least once this year by the town Council.
# http://www.bclocalnews.com/kootenay_rockies/crestonvalleyadvance/news/116760809.html
# During a period WWII, summer time (Daylight saying) was mandatory in Canada.
# In Creston, that was handled by shifting the area to PST (-8:00) then applying
# summer time to cause the offset to be -7:00, the same as it had been before
# the change. It can be argued that the timezone abbreviation during this
# period should be PDT rather than MST, but that doesn't seem important enough
# (to anyone) to further complicate the rules.
# The transition dates (and times) are guesses.
# From Matt Johnson (2015-09-21):
# Fort Nelson, BC, Canada will cancel DST this year. So while previously they
# were aligned with America/Vancouver, they're now aligned with
# America/Dawson_Creek.
# http://www.northernrockies.ca/EN/meta/news/archives/2015/northern-rockies-time-change.html
#
# From Tim Parenti (2015-09-23):
# This requires a new zone for the Northern Rockies Regional Municipality,
# America/Fort_Nelson. The resolution of 2014-12-08 was reached following a
# 2014-11-15 poll with nearly 75% support. Effectively, the municipality has
# been on MST (-0700) like Dawson Creek since it advanced its clocks on
# 2015-03-08.
#
-# From Paul Eggert (2015-09-23):
+# From Paul Eggert (2019-07-25):
# Shanks says Fort Nelson did not observe DST in 1946, unlike Vancouver.
+# Alois Triendl confirmed this on 07-22, citing the 1946-04-27 Vancouver Daily
+# Province. He also cited the 1946-09-28 Victoria Daily Times, which said
+# that Vancouver, Victoria, etc. "change at midnight Saturday"; for now,
+# guess they meant 02:00 Sunday since 02:00 was common practice in Vancouver.
+#
+# Early Vancouver, Volume Four, by Major J.S. Matthews, V.D., 2011 edition
+# says that a 1922 plebiscite adopted DST, but a 1923 plebiscite rejected it.
+# http://former.vancouver.ca/ctyclerk/archives/digitized/EarlyVan/SearchEarlyVan/Vol4pdf/MatthewsEarlyVancouverVol4_DaylightSavings.pdf
+# A catalog entry for a newspaper clipping seems to indicate that Vancouver
+# observed DST in 1941 from 07-07 through 09-27; see
+# https://searcharchives.vancouver.ca/daylight-saving-1918-starts-again-july-7-1941-start-d-s-sept-27-end-of-d-s-1941
+# We have no further details, so omit them for now.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Vanc 1918 only - Apr 14 2:00 1:00 D
Rule Vanc 1918 only - Oct 27 2:00 0 S
Rule Vanc 1942 only - Feb 9 2:00 1:00 W # War
Rule Vanc 1945 only - Aug 14 23:00u 1:00 P # Peace
Rule Vanc 1945 only - Sep 30 2:00 0 S
Rule Vanc 1946 1986 - Apr lastSun 2:00 1:00 D
-Rule Vanc 1946 only - Oct 13 2:00 0 S
+Rule Vanc 1946 only - Sep 29 2:00 0 S
Rule Vanc 1947 1961 - Sep lastSun 2:00 0 S
Rule Vanc 1962 2006 - Oct lastSun 2:00 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Vancouver -8:12:28 - LMT 1884
-8:00 Vanc P%sT 1987
-8:00 Canada P%sT
Zone America/Dawson_Creek -8:00:56 - LMT 1884
-8:00 Canada P%sT 1947
-8:00 Vanc P%sT 1972 Aug 30 2:00
-7:00 - MST
Zone America/Fort_Nelson -8:10:47 - LMT 1884
-8:00 Vanc P%sT 1946
-8:00 - PST 1947
-8:00 Vanc P%sT 1987
-8:00 Canada P%sT 2015 Mar 8 2:00
-7:00 - MST
Zone America/Creston -7:46:04 - LMT 1884
-7:00 - MST 1916 Oct 1
-8:00 - PST 1918 Jun 2
-7:00 - MST
# Northwest Territories, Nunavut, Yukon
# From Paul Eggert (2006-03-22):
# Dawson switched to PST in 1973. Inuvik switched to MST in 1979.
# Mathew Englander (1996-10-07) gives the following refs:
# * 1967. Paragraph 28(34)(g) of the Interpretation Act, S.C. 1967-68,
# c. 7 defines Yukon standard time as UTC-9....
# see Interpretation Act, R.S.C. 1985, c. I-21, s. 35(1).
# [https://www.canlii.org/en/ca/laws/stat/rsc-1985-c-i-21/latest/rsc-1985-c-i-21.html]
# * C.O. 1973/214 switched Yukon to PST on 1973-10-28 00:00.
# * O.I.C. 1980/02 established DST.
# * O.I.C. 1987/056 changed DST to Apr firstSun 2:00 to Oct lastSun 2:00.
# From Brian Inglis (2015-04-14):
#
# I tried to trace the history of Yukon time and found the following
# regulations, giving the reference title and URL if found, regulation name,
# and relevant quote if available. Each regulation specifically revokes its
# predecessor. The final reference is to the current Interpretation Act
# authorizing and resulting from these regulatory changes.
#
# Only recent regulations were retrievable via Yukon government site search or
# index, and only some via Canadian legal sources. Other sources used include
# articles titled "Standard Time and Time Zones in Canada" from JRASC via ADS
# Abstracts, cited by ADO for 1932 ..., and updated versions from 1958 and
# 1970 quoted below; each article includes current extracts from provincial
# and territorial ST and DST regulations at the end, summaries and details of
# standard times and daylight saving time at many locations across Canada,
# with time zone maps, tables and calculations for Canadian Sunrise, Sunset,
# and LMST; they also cover many countries and global locations, with a chart
# and table showing current Universal Time offsets, and may be useful as
# another source of information for 1970 and earlier.
#
# * Standard Time and Time Zones in Canada; Smith, C.C.; JRASC, Vol. 26,
# pp.49-77; February 1932; SAO/NASA Astrophysics Data System (ADS)
# http://adsabs.harvard.edu/abs/1932JRASC..26...49S from p.75:
# Yukon Interpretation Ordinance
# Yukon standard time is the local mean time at the one hundred and
# thirty-fifth meridian.
#
# * Standard Time and Time Zones in Canada; Smith, C.C.; Thomson, Malcolm M.;
# JRASC, Vol. 52, pp.193-223; October 1958; SAO/NASA Astrophysics Data System
# (ADS) http://adsabs.harvard.edu/abs/1958JRASC..52..193S from pp.220-1:
# Yukon Interpretation Ordinance, 1955, Chap. 16.
#
# (1) Subject to this section, standard time shall be reckoned as nine
# hours behind Greenwich Time and called Yukon Standard Time.
#
# (2) Notwithstanding subsection (1), the Commissioner may make regulations
# varying the manner of reckoning standard time.
#
# * Yukon Territory Commissioner's Order 1966-20 Interpretation Ordinance
# [no online source found]
#
# * Standard Time and Time Zones in Canada; Thomson, Malcolm M.; JRASC,
# Vol. 64, pp.129-162; June 1970; SAO/NASA Astrophysics Data System (ADS)
# http://adsabs.harvard.edu/abs/1970JRASC..64..129T from p.156: Yukon
# Territory Commissioner's Order 1967-59 Interpretation Ordinance ...
#
# 1. Commissioner's Order 1966-20 dated at Whitehorse in the Yukon
# Territory on 27th January, 1966, is hereby revoked.
#
# 2. Yukon (East) Standard Time as defined by section 36 of the
# Interpretation Ordinance from and after mid-night on the 28th day of May,
# 1967 shall be reckoned in the same manner as Pacific Standard Time, that
# is to say, eight hours behind Greenwich Time in the area of the Yukon
# Territory lying east of the 138th degree longitude west.
#
# 3. In the remainder of the Territory, lying west of the 138th degree
# longitude west, Yukon (West) Standard Time shall be reckoned as nine
# hours behind Greenwich Time.
#
# * Yukon Standard Time defined as Pacific Standard Time, YCO 1973/214
# https://www.canlii.org/en/yk/laws/regu/yco-1973-214/latest/yco-1973-214.html
# C.O. 1973/214 INTERPRETATION ACT ...
#
# 1. Effective October 28, 1973 Commissioner's Order 1967/59 is hereby
# revoked.
#
# 2. Yukon Standard Time as defined by section 36 of the Interpretation
# Act from and after midnight on the twenty-eighth day of October, 1973
# shall be reckoned in the same manner as Pacific Standard Time, that is
# to say eight hours behind Greenwich Time.
#
# * O.I.C. 1980/02 INTERPRETATION ACT
# [no online source found]
#
# * Yukon Daylight Saving Time, YOIC 1987/56
# https://www.canlii.org/en/yk/laws/regu/yoic-1987-56/latest/yoic-1987-56.html
# O.I.C. 1987/056 INTERPRETATION ACT ...
#
# In every year between
# (a) two o'clock in the morning in the first Sunday in April, and
# (b) two o'clock in the morning in the last Sunday in October,
# Standard Time shall be reckoned as seven hours behind Greenwich Time and
# called Yukon Daylight Saving Time.
# ...
# Dated ... 9th day of March, A.D., 1987.
#
# * Yukon Daylight Saving Time 2006, YOIC 2006/127
# https://www.canlii.org/en/yk/laws/regu/yoic-2006-127/latest/yoic-2006-127.html
# O.I.C. 2006/127 INTERPRETATION ACT ...
#
# 1. In Yukon each year the time for general purposes shall be 7 hours
# behind Greenwich mean time during the period commencing at two o'clock
# in the forenoon on the second Sunday of March and ending at two o'clock
# in the forenoon on the first Sunday of November and shall be called
# Yukon Daylight Saving Time.
#
# 2. Order-in-Council 1987/56 is revoked.
#
# 3. This order comes into force January 1, 2007.
#
# * Interpretation Act, RSY 2002, c 125
# https://www.canlii.org/en/yk/laws/stat/rsy-2002-c-125/latest/rsy-2002-c-125.html
# From Rives McDow (1999-09-04):
# Nunavut ... moved ... to incorporate the whole territory into one time zone.
# Nunavut moves to single time zone Oct. 31
# http://www.nunatsiaq.com/nunavut/nvt90903_13.html
#
# From Antoine Leca (1999-09-06):
# We then need to create a new timezone for the Kitikmeot region of Nunavut
# to differentiate it from the Yellowknife region.
# From Paul Eggert (1999-09-20):
# Basic Facts: The New Territory
# http://www.nunavut.com/basicfacts/english/basicfacts_1territory.html
# (1999) reports that Pangnirtung operates on eastern time,
# and that Coral Harbour does not observe DST. We don't know when
# Pangnirtung switched to eastern time; we'll guess 1995.
# From Rives McDow (1999-11-08):
# On October 31, when the rest of Nunavut went to Central time,
# Pangnirtung wobbled. Here is the result of their wobble:
#
# The following businesses and organizations in Pangnirtung use Central Time:
#
# First Air, Power Corp, Nunavut Construction, Health Center, RCMP,
# Eastern Arctic National Parks, A & D Specialist
#
# The following businesses and organizations in Pangnirtung use Eastern Time:
#
# Hamlet office, All other businesses, Both schools, Airport operator
#
# This has made for an interesting situation there, which warranted the news.
# No one there that I spoke with seems concerned, or has plans to
# change the local methods of keeping time, as it evidently does not
# really interfere with any activities or make things difficult locally.
# They plan to celebrate New Year's turn-over twice, one hour apart,
# so it appears that the situation will last at least that long.
# The Nunavut Intergovernmental Affairs hopes that they will "come to
# their senses", but the locals evidently don't see any problem with
# the current state of affairs.
# From Michaela Rodrigue, writing in the
# Nunatsiaq News (1999-11-19):
# http://www.nunatsiaqonline.ca/archives/nunavut991130/nvt91119_17.html
# Clyde River, Pangnirtung and Sanikiluaq now operate with two time zones,
# central - or Nunavut time - for government offices, and eastern time
# for municipal offices and schools.... Igloolik [was similar but then]
# made the switch to central time on Saturday, Nov. 6.
# From Paul Eggert (2000-10-02):
# Matthews and Vincent (1998) say the following, but we lack histories
# for these potential new Zones.
#
# The Canadian Forces station at Alert uses Eastern Time while the
# handful of residents at the Eureka weather station [in the Central
# zone] skip daylight savings. Baffin Island, which is crossed by the
# Central, Eastern and Atlantic Time zones only uses Eastern Time.
# Gjoa Haven, Taloyoak and Pelly Bay all use Mountain instead of
# Central Time and Southampton Island [in the Central zone] is not
# required to use daylight savings.
# From <http://www.nunatsiaqonline.ca/archives/nunavut001130/nvt21110_02.html>
# Nunavut now has two time zones (2000-11-10):
# The Nunavut government would allow its employees in Kugluktuk and
# Cambridge Bay to operate on central time year-round, putting them
# one hour behind the rest of Nunavut for six months during the winter.
# At the end of October the two communities had rebelled against
# Nunavut's unified time zone, refusing to shift to eastern time with
# the rest of the territory for the winter. Cambridge Bay remained on
# central time, while Kugluktuk, even farther west, reverted to
# mountain time, which they had used before the advent of Nunavut's
# unified time zone in 1999.
#
# From Rives McDow (2001-01-20), quoting the Nunavut government:
# The preceding decision came into effect at midnight, Saturday Nov 4, 2000.
# From Paul Eggert (2000-12-04):
# Let's just keep track of the official times for now.
# From Rives McDow (2001-03-07):
# The premier of Nunavut has issued a ministerial statement advising
# that effective 2001-04-01, the territory of Nunavut will revert
# back to three time zones (mountain, central, and eastern). Of the
# cities in Nunavut, Coral Harbor is the only one that I know of that
# has said it will not observe dst, staying on EST year round. I'm
# checking for more info, and will get back to you if I come up with
# more.
# [Also see <http://www.nunatsiaq.com/nunavut/nvt10309_06.html> (2001-03-09).]
# From Gwillim Law (2005-05-21):
# According to ...
# http://www.canadiangeographic.ca/Magazine/SO98/geomap.asp
# (from a 1998 Canadian Geographic article), the de facto and de jure time
# for Southampton Island (at the north end of Hudson Bay) is UTC-5 all year
# round. Using Google, it's easy to find other websites that confirm this.
# I wasn't able to find how far back this time regimen goes, but since it
# predates the creation of Nunavut, it probably goes back many years....
# The Inuktitut name of Coral Harbour is Sallit, but it's rarely used.
#
# From Paul Eggert (2014-10-17):
# For lack of better information, assume that Southampton Island observed
# daylight saving only during wartime. Gwillim Law's email also
# mentioned maps now maintained by National Research Council Canada;
# see above for an up-to-date link.
# From Chris Walton (2007-03-01):
# ... the community of Resolute (located on Cornwallis Island in
# Nunavut) moved from Central Time to Eastern Time last November.
# Basically the community did not change its clocks at the end of
# daylight saving....
# http://www.nnsl.com/frames/newspapers/2006-11/nov13_06none.html
# From Chris Walton (2011-03-21):
# Back in 2007 I initiated the creation of a new "zone file" for Resolute
# Bay. Resolute Bay is a small community located about 900km north of
# the Arctic Circle. The zone file was required because Resolute Bay had
# decided to use UTC-5 instead of UTC-6 for the winter of 2006-2007.
#
# According to new information which I received last week, Resolute Bay
# went back to using UTC-6 in the winter of 2007-2008...
#
# On March 11/2007 most of Canada went onto daylight saving. On March
# 14/2007 I phoned the Resolute Bay hamlet office to do a "time check." I
# talked to somebody that was both knowledgeable and helpful. I was able
# to confirm that Resolute Bay was still operating on UTC-5. It was
# explained to me that Resolute Bay had been on the Eastern Time zone
# (EST) in the winter, and was now back on the Central Time zone (CDT).
# i.e. the time zone had changed twice in the last year but the clocks
# had not moved. The residents had to know which time zone they were in
# so they could follow the correct TV schedule...
#
# On Nov 02/2008 most of Canada went onto standard time. On Nov 03/2008 I
# phoned the Resolute Bay hamlet office...[D]ue to the challenging nature
# of the phone call, I decided to seek out an alternate source of
# information. I found an e-mail address for somebody by the name of
# Stephanie Adams whose job was listed as "Inns North Support Officer for
# Arctic Co-operatives." I was under the impression that Stephanie lived
# and worked in Resolute Bay...
#
# On March 14/2011 I phoned the hamlet office again. I was told that
# Resolute Bay had been using Central Standard Time over the winter of
# 2010-2011 and that the clocks had therefore been moved one hour ahead
# on March 13/2011. The person I talked to was aware that Resolute Bay
# had previously experimented with Eastern Standard Time but he could not
# tell me when the practice had stopped.
#
# On March 17/2011 I searched the Web to find an e-mail address of
# somebody that might be able to tell me exactly when Resolute Bay went
# off Eastern Standard Time. I stumbled on the name "Aziz Kheraj." Aziz
# used to be the mayor of Resolute Bay and he apparently owns half the
# businesses including "South Camp Inn." This website has some info on
# Aziz:
# http://www.uphere.ca/node/493
#
# I sent Aziz an e-mail asking when Resolute Bay had stopped using
# Eastern Standard Time.
#
# Aziz responded quickly with this: "hi, The time was not changed for the
# 1 year only, the following year, the community went back to the old way
# of "spring ahead-fall behind" currently we are zulu plus 5 hrs and in
# the winter Zulu plus 6 hrs"
#
# This of course conflicted with everything I had ascertained in November 2008.
#
# I sent Aziz a copy of my 2008 e-mail exchange with Stephanie. Aziz
# responded with this: "Hi, Stephanie lives in Winnipeg. I live here, You
# may want to check with the weather office in Resolute Bay or do a
# search on the weather through Env. Canada. web site"
#
# If I had realized the Stephanie did not live in Resolute Bay I would
# never have contacted her. I now believe that all the information I
# obtained in November 2008 should be ignored...
# I apologize for reporting incorrect information in 2008.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule NT_YK 1918 only - Apr 14 2:00 1:00 D
Rule NT_YK 1918 only - Oct 27 2:00 0 S
Rule NT_YK 1919 only - May 25 2:00 1:00 D
Rule NT_YK 1919 only - Nov 1 0:00 0 S
Rule NT_YK 1942 only - Feb 9 2:00 1:00 W # War
Rule NT_YK 1945 only - Aug 14 23:00u 1:00 P # Peace
Rule NT_YK 1945 only - Sep 30 2:00 0 S
Rule NT_YK 1965 only - Apr lastSun 0:00 2:00 DD
Rule NT_YK 1965 only - Oct lastSun 2:00 0 S
Rule NT_YK 1980 1986 - Apr lastSun 2:00 1:00 D
Rule NT_YK 1980 2006 - Oct lastSun 2:00 0 S
Rule NT_YK 1987 2006 - Apr Sun>=1 2:00 1:00 D
# Zone NAME STDOFF RULES FORMAT [UNTIL]
# aka Panniqtuuq
Zone America/Pangnirtung 0 - -00 1921 # trading post est.
-4:00 NT_YK A%sT 1995 Apr Sun>=1 2:00
-5:00 Canada E%sT 1999 Oct 31 2:00
-6:00 Canada C%sT 2000 Oct 29 2:00
-5:00 Canada E%sT
# formerly Frobisher Bay
Zone America/Iqaluit 0 - -00 1942 Aug # Frobisher Bay est.
-5:00 NT_YK E%sT 1999 Oct 31 2:00
-6:00 Canada C%sT 2000 Oct 29 2:00
-5:00 Canada E%sT
# aka Qausuittuq
Zone America/Resolute 0 - -00 1947 Aug 31 # Resolute founded
-6:00 NT_YK C%sT 2000 Oct 29 2:00
-5:00 - EST 2001 Apr 1 3:00
-6:00 Canada C%sT 2006 Oct 29 2:00
-5:00 - EST 2007 Mar 11 3:00
-6:00 Canada C%sT
# aka Kangiqiniq
Zone America/Rankin_Inlet 0 - -00 1957 # Rankin Inlet founded
-6:00 NT_YK C%sT 2000 Oct 29 2:00
-5:00 - EST 2001 Apr 1 3:00
-6:00 Canada C%sT
# aka Iqaluktuuttiaq
Zone America/Cambridge_Bay 0 - -00 1920 # trading post est.?
-7:00 NT_YK M%sT 1999 Oct 31 2:00
-6:00 Canada C%sT 2000 Oct 29 2:00
-5:00 - EST 2000 Nov 5 0:00
-6:00 - CST 2001 Apr 1 3:00
-7:00 Canada M%sT
Zone America/Yellowknife 0 - -00 1935 # Yellowknife founded?
-7:00 NT_YK M%sT 1980
-7:00 Canada M%sT
Zone America/Inuvik 0 - -00 1953 # Inuvik founded
-8:00 NT_YK P%sT 1979 Apr lastSun 2:00
-7:00 NT_YK M%sT 1980
-7:00 Canada M%sT
Zone America/Whitehorse -9:00:12 - LMT 1900 Aug 20
-9:00 NT_YK Y%sT 1967 May 28 0:00
-8:00 NT_YK P%sT 1980
-8:00 Canada P%sT
Zone America/Dawson -9:17:40 - LMT 1900 Aug 20
-9:00 NT_YK Y%sT 1973 Oct 28 0:00
-8:00 NT_YK P%sT 1980
-8:00 Canada P%sT
###############################################################################
# Mexico
# From Paul Eggert (2014-12-07):
# The Investigation and Analysis Service of the
# Mexican Library of Congress (MLoC) has published a
# history of Mexican local time (in Spanish)
# http://www.diputados.gob.mx/bibliot/publica/inveyana/polisoc/horver/index.htm
#
# Here are the discrepancies between Shanks & Pottenger (S&P) and the MLoC.
# (In all cases we go with the MLoC.)
# S&P report that Baja was at -8:00 in 1922/1923.
# S&P say the 1930 transition in Baja was 1930-11-16.
# S&P report no DST during summer 1931.
# S&P report a transition at 1932-03-30 23:00, not 1932-04-01.
# From Gwillim Law (2001-02-20):
# There are some other discrepancies between the Decrees page and the
# tz database. I think they can best be explained by supposing that
# the researchers who prepared the Decrees page failed to find some of
# the relevant documents.
# From Alan Perry (1996-02-15):
# A guy from our Mexico subsidiary finally found the Presidential Decree
# outlining the timezone changes in Mexico.
#
# ------------- Begin Forwarded Message -------------
#
# I finally got my hands on the Official Presidential Decree that sets up the
# rules for the DST changes. The rules are:
#
# 1. The country is divided in 3 timezones:
# - Baja California Norte (the Mexico/BajaNorte TZ)
# - Baja California Sur, Nayarit, Sinaloa and Sonora (the Mexico/BajaSur TZ)
# - The rest of the country (the Mexico/General TZ)
#
# 2. From the first Sunday in April at 2:00 AM to the last Sunday in October
# at 2:00 AM, the times in each zone are as follows:
# BajaNorte: GMT+7
# BajaSur: GMT+6
# General: GMT+5
#
# 3. The rest of the year, the times are as follows:
# BajaNorte: GMT+8
# BajaSur: GMT+7
# General: GMT+6
#
# The Decree was published in Mexico's Official Newspaper on January 4th.
#
# -------------- End Forwarded Message --------------
# From Paul Eggert (1996-06-12):
# For an English translation of the decree, see
# "Diario Oficial: Time Zone Changeover" (1996-01-04).
# http://mexico-travel.com/extra/timezone_eng.html
# From Rives McDow (1998-10-08):
# The State of Quintana Roo has reverted back to central STD and DST times
# (i.e. UTC -0600 and -0500 as of 1998-08-02).
# From Rives McDow (2000-01-10):
# Effective April 4, 1999 at 2:00 AM local time, Sonora changed to the time
# zone 5 hours from the International Date Line, and will not observe daylight
# savings time so as to stay on the same time zone as the southern part of
# Arizona year round.
# From Jesper Nørgaard, translating
# <http://www.reforma.com/nacional/articulo/064327/> (2001-01-17):
# In Oaxaca, the 55.000 teachers from the Section 22 of the National
# Syndicate of Education Workers, refuse to apply daylight saving each
# year, so that the more than 10,000 schools work at normal hour the
# whole year.
# From Gwillim Law (2001-01-19):
# <http://www.reforma.com/negocios_y_dinero/articulo/064481/> ... says
# (translated):...
# January 17, 2000 - The Energy Secretary, Ernesto Martens, announced
# that Summer Time will be reduced from seven to five months, starting
# this year....
# http://www.publico.com.mx/scripts/texto3.asp?action=pagina&pag=21&pos=p&secc=naci&date=01/17/2001
# [translated], says "summer time will ... take effect on the first Sunday
# in May, and end on the last Sunday of September.
# From Arthur David Olson (2001-01-25):
# The 2001-01-24 traditional Washington Post contained the page one
# story "Timely Issue Divides Mexicans."...
# http://www.washingtonpost.com/wp-dyn/articles/A37383-2001Jan23.html
# ... Mexico City Mayor López Obrador "...is threatening to keep
# Mexico City and its 20 million residents on a different time than
# the rest of the country..." In particular, López Obrador would abolish
# observation of Daylight Saving Time.
# Official statute published by the Energy Department
# http://www.conae.gob.mx/ahorro/decretohorver2001.html#decre
# (2001-02-01) shows Baja and Chihauhua as still using US DST rules,
# and Sonora with no DST. This was reported by Jesper Nørgaard (2001-02-03).
# From Paul Eggert (2001-03-03):
#
# https://www.latimes.com/archives/la-xpm-2001-mar-03-mn-32561-story.html
# James F. Smith writes in today's LA Times
# * Sonora will continue to observe standard time.
# * Last week Mexico City's mayor Andrés Manuel López Obrador decreed that
# the Federal District will not adopt DST.
# * 4 of 16 district leaders announced they'll ignore the decree.
# * The decree does not affect federal-controlled facilities including
# the airport, banks, hospitals, and schools.
#
# For now we'll assume that the Federal District will bow to federal rules.
# From Jesper Nørgaard (2001-04-01):
# I found some references to the Mexican application of daylight
# saving, which modifies what I had already sent you, stating earlier
# that a number of northern Mexican states would go on daylight
# saving. The modification reverts this to only cover Baja California
# (Norte), while all other states (except Sonora, who has no daylight
# saving all year) will follow the original decree of president
# Vicente Fox, starting daylight saving May 6, 2001 and ending
# September 30, 2001.
# References: "Diario de Monterrey" <http://www.diariodemonterrey.com/index.asp>
# Palabra <http://palabra.infosel.com/010331/primera/ppri3101.pdf> (2001-03-31)
# From Reuters (2001-09-04):
# Mexico's Supreme Court on Tuesday declared that daylight savings was
# unconstitutional in Mexico City, creating the possibility the
# capital will be in a different time zone from the rest of the nation
# next year.... The Supreme Court's ruling takes effect at 2:00
# a.m. (0800 GMT) on Sept. 30, when Mexico is scheduled to revert to
# standard time. "This is so residents of the Federal District are not
# subject to unexpected time changes," a statement from the court said.
# From Jesper Nørgaard Welen (2002-03-12):
# ... consulting my local grocery store(!) and my coworkers, they all insisted
# that a new decision had been made to reinstate US style DST in Mexico....
# http://www.conae.gob.mx/ahorro/horaver2001_m1_2002.html (2002-02-20)
# confirms this. Sonora as usual is the only state where DST is not applied.
# From Steffen Thorsen (2009-12-28):
#
# Steffen Thorsen wrote:
# > Mexico's House of Representatives has approved a proposal for northern
# > Mexico's border cities to share the same daylight saving schedule as
# > the United States.
# Now this has passed both the Congress and the Senate, so starting from
# 2010, some border regions will be the same:
# http://www.signonsandiego.com/news/2009/dec/28/clocks-will-match-both-sides-border/
# http://www.elmananarey.com/diario/noticia/nacional/noticias/empatan_horario_de_frontera_con_eu/621939
# (Spanish)
#
# Could not find the new law text, but the proposed law text changes are here:
# http://gaceta.diputados.gob.mx/Gaceta/61/2009/dic/20091210-V.pdf
# (Gaceta Parlamentaria)
#
# There is also a list of the votes here:
# http://gaceta.diputados.gob.mx/Gaceta/61/2009/dic/V2-101209.html
#
# Our page:
# https://www.timeanddate.com/news/time/north-mexico-dst-change.html
# From Arthur David Olson (2010-01-20):
# The page
# http://dof.gob.mx/nota_detalle.php?codigo=5127480&fecha=06/01/2010
# includes this text:
# En los municipios fronterizos de Tijuana y Mexicali en Baja California;
# Juárez y Ojinaga en Chihuahua; Acuña y Piedras Negras en Coahuila;
# Anáhuac en Nuevo León; y Nuevo Laredo, Reynosa y Matamoros en
# Tamaulipas, la aplicación de este horario estacional surtirá efecto
# desde las dos horas del segundo domingo de marzo y concluirá a las dos
# horas del primer domingo de noviembre.
# En los municipios fronterizos que se encuentren ubicados en la franja
# fronteriza norte en el territorio comprendido entre la línea
# internacional y la línea paralela ubicada a una distancia de veinte
# kilómetros, así como la Ciudad de Ensenada, Baja California, hacia el
# interior del país, la aplicación de este horario estacional surtirá
# efecto desde las dos horas del segundo domingo de marzo y concluirá a
# las dos horas del primer domingo de noviembre.
# From Steffen Thorsen (2014-12-08), translated by Gwillim Law:
# The Mexican state of Quintana Roo will likely change to EST in 2015.
#
# http://www.unioncancun.mx/articulo/2014/12/04/medio-ambiente/congreso-aprueba-una-hora-mas-de-sol-en-qroo
# "With this change, the time conflict that has existed between the municipios
# of Quintana Roo and the municipio of Felipe Carrillo Puerto may come to an
# end. The latter declared itself in rebellion 15 years ago when a time change
# was initiated in Mexico, and since then it has refused to change its time
# zone along with the rest of the country."
#
# From Steffen Thorsen (2015-01-14), translated by Gwillim Law:
# http://sipse.com/novedades/confirman-aplicacion-de-nueva-zona-horaria-para-quintana-roo-132331.html
# "...the new time zone will come into effect at two o'clock on the first Sunday
# of February, when we will have to advance the clock one hour from its current
# time..."
# Also, the new zone will not use DST.
#
# From Carlos Raúl Perasso (2015-02-02):
# The decree that modifies the Mexican Hour System Law has finally
# been published at the Diario Oficial de la Federación
# http://www.dof.gob.mx/nota_detalle.php?codigo=5380123&fecha=31/01/2015
# It establishes 5 zones for Mexico:
# 1- Zona Centro (Central Zone): Corresponds to longitude 90 W,
# includes most of Mexico, excluding what's mentioned below.
# 2- Zona Pacífico (Pacific Zone): Longitude 105 W, includes the
# states of Baja California Sur; Chihuahua; Nayarit (excluding Bahía
# de Banderas which lies in Central Zone); Sinaloa and Sonora.
# 3- Zona Noroeste (Northwest Zone): Longitude 120 W, includes the
# state of Baja California.
# 4- Zona Sureste (Southeast Zone): Longitude 75 W, includes the state
# of Quintana Roo.
# 5- The islands, reefs and keys shall take their timezone from the
# longitude they are located at.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Mexico 1939 only - Feb 5 0:00 1:00 D
Rule Mexico 1939 only - Jun 25 0:00 0 S
Rule Mexico 1940 only - Dec 9 0:00 1:00 D
Rule Mexico 1941 only - Apr 1 0:00 0 S
Rule Mexico 1943 only - Dec 16 0:00 1:00 W # War
Rule Mexico 1944 only - May 1 0:00 0 S
Rule Mexico 1950 only - Feb 12 0:00 1:00 D
Rule Mexico 1950 only - Jul 30 0:00 0 S
Rule Mexico 1996 2000 - Apr Sun>=1 2:00 1:00 D
Rule Mexico 1996 2000 - Oct lastSun 2:00 0 S
Rule Mexico 2001 only - May Sun>=1 2:00 1:00 D
Rule Mexico 2001 only - Sep lastSun 2:00 0 S
Rule Mexico 2002 max - Apr Sun>=1 2:00 1:00 D
Rule Mexico 2002 max - Oct lastSun 2:00 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
# Quintana Roo; represented by Cancún
Zone America/Cancun -5:47:04 - LMT 1922 Jan 1 0:12:56
-6:00 - CST 1981 Dec 23
-5:00 Mexico E%sT 1998 Aug 2 2:00
-6:00 Mexico C%sT 2015 Feb 1 2:00
-5:00 - EST
# Campeche, Yucatán; represented by Mérida
Zone America/Merida -5:58:28 - LMT 1922 Jan 1 0:01:32
-6:00 - CST 1981 Dec 23
-5:00 - EST 1982 Dec 2
-6:00 Mexico C%sT
# Coahuila, Nuevo León, Tamaulipas (near US border)
# This includes the following municipalities:
# in Coahuila: Ocampo, Acuña, Zaragoza, Jiménez, Piedras Negras, Nava,
# Guerrero, Hidalgo.
# in Nuevo León: Anáhuac, Los Aldama.
# in Tamaulipas: Nuevo Laredo, Guerrero, Mier, Miguel Alemán, Camargo,
# Gustavo Díaz Ordaz, Reynosa, Río Bravo, Valle Hermoso, Matamoros.
# See: Inicia mañana Horario de Verano en zona fronteriza, El Universal,
# 2016-03-12
# http://www.eluniversal.com.mx/articulo/estados/2016/03/12/inicia-manana-horario-de-verano-en-zona-fronteriza
Zone America/Matamoros -6:40:00 - LMT 1921 Dec 31 23:20:00
-6:00 - CST 1988
-6:00 US C%sT 1989
-6:00 Mexico C%sT 2010
-6:00 US C%sT
# Durango; Coahuila, Nuevo León, Tamaulipas (away from US border)
Zone America/Monterrey -6:41:16 - LMT 1921 Dec 31 23:18:44
-6:00 - CST 1988
-6:00 US C%sT 1989
-6:00 Mexico C%sT
# Central Mexico
Zone America/Mexico_City -6:36:36 - LMT 1922 Jan 1 0:23:24
-7:00 - MST 1927 Jun 10 23:00
-6:00 - CST 1930 Nov 15
-7:00 - MST 1931 May 1 23:00
-6:00 - CST 1931 Oct
-7:00 - MST 1932 Apr 1
-6:00 Mexico C%sT 2001 Sep 30 2:00
-6:00 - CST 2002 Feb 20
-6:00 Mexico C%sT
# Chihuahua (near US border)
# This includes the municipalities of Janos, Ascensión, Juárez, Guadalupe,
# Práxedis G Guerrero, Coyame del Sotol, Ojinaga, and Manuel Benavides.
# (See the 2016-03-12 El Universal source mentioned above.)
Zone America/Ojinaga -6:57:40 - LMT 1922 Jan 1 0:02:20
-7:00 - MST 1927 Jun 10 23:00
-6:00 - CST 1930 Nov 15
-7:00 - MST 1931 May 1 23:00
-6:00 - CST 1931 Oct
-7:00 - MST 1932 Apr 1
-6:00 - CST 1996
-6:00 Mexico C%sT 1998
-6:00 - CST 1998 Apr Sun>=1 3:00
-7:00 Mexico M%sT 2010
-7:00 US M%sT
# Chihuahua (away from US border)
Zone America/Chihuahua -7:04:20 - LMT 1921 Dec 31 23:55:40
-7:00 - MST 1927 Jun 10 23:00
-6:00 - CST 1930 Nov 15
-7:00 - MST 1931 May 1 23:00
-6:00 - CST 1931 Oct
-7:00 - MST 1932 Apr 1
-6:00 - CST 1996
-6:00 Mexico C%sT 1998
-6:00 - CST 1998 Apr Sun>=1 3:00
-7:00 Mexico M%sT
# Sonora
Zone America/Hermosillo -7:23:52 - LMT 1921 Dec 31 23:36:08
-7:00 - MST 1927 Jun 10 23:00
-6:00 - CST 1930 Nov 15
-7:00 - MST 1931 May 1 23:00
-6:00 - CST 1931 Oct
-7:00 - MST 1932 Apr 1
-6:00 - CST 1942 Apr 24
-7:00 - MST 1949 Jan 14
-8:00 - PST 1970
-7:00 Mexico M%sT 1999
-7:00 - MST
# From Alexander Krivenyshev (2010-04-21):
# According to news, Bahía de Banderas (Mexican state of Nayarit)
# changed time zone UTC-7 to new time zone UTC-6 on April 4, 2010 (to
# share the same time zone as nearby city Puerto Vallarta, Jalisco).
#
# (Spanish)
# Bahía de Banderas homologa su horario al del centro del
# país, a partir de este domingo
# http://www.nayarit.gob.mx/notes.asp?id=20748
#
# Bahía de Banderas homologa su horario con el del Centro del
# País
# http://www.bahiadebanderas.gob.mx/principal/index.php?option=com_content&view=article&id=261:bahia-de-banderas-homologa-su-horario-con-el-del-centro-del-pais&catid=42:comunicacion-social&Itemid=50
#
# (English)
# Puerto Vallarta and Bahía de Banderas: One Time Zone
# http://virtualvallarta.com/puertovallarta/puertovallarta/localnews/2009-12-03-Puerto-Vallarta-and-Bahia-de-Banderas-One-Time-Zone.shtml
# http://www.worldtimezone.com/dst_news/dst_news_mexico08.html
#
# "Mexico's Senate approved the amendments to the Mexican Schedule System that
# will allow Bahía de Banderas and Puerto Vallarta to share the same time
# zone ..."
# Baja California Sur, Nayarit, Sinaloa
# From Arthur David Olson (2010-05-01):
# Use "Bahia_Banderas" to keep the name to fourteen characters.
# Mazatlán
Zone America/Mazatlan -7:05:40 - LMT 1921 Dec 31 23:54:20
-7:00 - MST 1927 Jun 10 23:00
-6:00 - CST 1930 Nov 15
-7:00 - MST 1931 May 1 23:00
-6:00 - CST 1931 Oct
-7:00 - MST 1932 Apr 1
-6:00 - CST 1942 Apr 24
-7:00 - MST 1949 Jan 14
-8:00 - PST 1970
-7:00 Mexico M%sT
# Bahía de Banderas
Zone America/Bahia_Banderas -7:01:00 - LMT 1921 Dec 31 23:59:00
-7:00 - MST 1927 Jun 10 23:00
-6:00 - CST 1930 Nov 15
-7:00 - MST 1931 May 1 23:00
-6:00 - CST 1931 Oct
-7:00 - MST 1932 Apr 1
-6:00 - CST 1942 Apr 24
-7:00 - MST 1949 Jan 14
-8:00 - PST 1970
-7:00 Mexico M%sT 2010 Apr 4 2:00
-6:00 Mexico C%sT
# Baja California
Zone America/Tijuana -7:48:04 - LMT 1922 Jan 1 0:11:56
-7:00 - MST 1924
-8:00 - PST 1927 Jun 10 23:00
-7:00 - MST 1930 Nov 15
-8:00 - PST 1931 Apr 1
-8:00 1:00 PDT 1931 Sep 30
-8:00 - PST 1942 Apr 24
-8:00 1:00 PWT 1945 Aug 14 23:00u
-8:00 1:00 PPT 1945 Nov 12 # Peace
-8:00 - PST 1948 Apr 5
-8:00 1:00 PDT 1949 Jan 14
-8:00 - PST 1954
-8:00 CA P%sT 1961
-8:00 - PST 1976
-8:00 US P%sT 1996
-8:00 Mexico P%sT 2001
-8:00 US P%sT 2002 Feb 20
-8:00 Mexico P%sT 2010
-8:00 US P%sT
# From Paul Eggert (2006-03-22):
# Formerly there was an America/Ensenada zone, which differed from
# America/Tijuana only in that it did not observe DST from 1976
# through 1995. This was as per Shanks (1999). But Shanks & Pottenger say
# Ensenada did not observe DST from 1948 through 1975. Guy Harris reports
# that the 1987 OAG says "Only Ensenada, Mexicali, San Felipe and
# Tijuana observe DST," which agrees with Shanks & Pottenger but implies that
# DST-observance was a town-by-town matter back then. This concerns
# data after 1970 so most likely there should be at least one Zone
# other than America/Tijuana for Baja, but it's not clear yet what its
# name or contents should be.
#
# From Paul Eggert (2015-10-08):
# Formerly there was an America/Santa_Isabel zone, but this appears to
# have come from a misreading of
# http://dof.gob.mx/nota_detalle.php?codigo=5127480&fecha=06/01/2010
# It has been moved to the 'backward' file.
#
#
# Revillagigedo Is
# no information
###############################################################################
# Anguilla
# Antigua and Barbuda
# See America/Port_of_Spain.
# Bahamas
#
# For 1899 Milne gives -5:09:29.5; round that.
#
# From Sue Williams (2006-12-07):
# The Bahamas announced about a month ago that they plan to change their DST
# rules to sync with the U.S. starting in 2007....
# http://www.jonesbahamas.com/?c=45&a=10412
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Bahamas 1964 1975 - Oct lastSun 2:00 0 S
Rule Bahamas 1964 1975 - Apr lastSun 2:00 1:00 D
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Nassau -5:09:30 - LMT 1912 Mar 2
-5:00 Bahamas E%sT 1976
-5:00 US E%sT
# Barbados
# For 1899 Milne gives -3:58:29.2; round that.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Barb 1977 only - Jun 12 2:00 1:00 D
Rule Barb 1977 1978 - Oct Sun>=1 2:00 0 S
Rule Barb 1978 1980 - Apr Sun>=15 2:00 1:00 D
Rule Barb 1979 only - Sep 30 2:00 0 S
Rule Barb 1980 only - Sep 25 2:00 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Barbados -3:58:29 - LMT 1924 # Bridgetown
-3:58:29 - BMT 1932 # Bridgetown Mean Time
-4:00 Barb A%sT
# Belize
# Whitman entirely disagrees with Shanks; go with Shanks & Pottenger.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Belize 1918 1942 - Oct Sun>=2 0:00 0:30 -0530
Rule Belize 1919 1943 - Feb Sun>=9 0:00 0 CST
Rule Belize 1973 only - Dec 5 0:00 1:00 CDT
Rule Belize 1974 only - Feb 9 0:00 0 CST
Rule Belize 1982 only - Dec 18 0:00 1:00 CDT
Rule Belize 1983 only - Feb 12 0:00 0 CST
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Belize -5:52:48 - LMT 1912 Apr
-6:00 Belize %s
# Bermuda
# For 1899 Milne gives -4:19:18.3 as the meridian of the clock tower,
# Bermuda dockyard, Ireland I; round that.
# From Dan Jones, reporting in The Royal Gazette (2006-06-26):
# Next year, however, clocks in the US will go forward on the second Sunday
# in March, until the first Sunday in November. And, after the Time Zone
# (Seasonal Variation) Bill 2006 was passed in the House of Assembly on
# Friday, the same thing will happen in Bermuda.
# http://www.theroyalgazette.com/apps/pbcs.dll/article?AID=/20060529/NEWS/105290135
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Atlantic/Bermuda -4:19:18 - LMT 1930 Jan 1 2:00 # Hamilton
-4:00 - AST 1974 Apr 28 2:00
-4:00 Canada A%sT 1976
-4:00 US A%sT
# Cayman Is
# See America/Panama.
# Costa Rica
# Milne gives -5:36:13.3 as San José mean time; round to nearest.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule CR 1979 1980 - Feb lastSun 0:00 1:00 D
Rule CR 1979 1980 - Jun Sun>=1 0:00 0 S
Rule CR 1991 1992 - Jan Sat>=15 0:00 1:00 D
# IATA SSIM (1991-09) says the following was at 1:00;
# go with Shanks & Pottenger.
Rule CR 1991 only - Jul 1 0:00 0 S
Rule CR 1992 only - Mar 15 0:00 0 S
# There are too many San Josés elsewhere, so we'll use 'Costa Rica'.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Costa_Rica -5:36:13 - LMT 1890 # San José
-5:36:13 - SJMT 1921 Jan 15 # San José Mean Time
-6:00 CR C%sT
# Coco
# no information; probably like America/Costa_Rica
# Cuba
# From Paul Eggert (2013-02-21):
# Milne gives -5:28:50.45 for the observatory at Havana, -5:29:23.57
# for the port, and -5:30 for meteorological observations.
# For now, stick with Shanks & Pottenger.
# From Arthur David Olson (1999-03-29):
# The 1999-03-28 exhibition baseball game held in Havana, Cuba, between
# the Cuban National Team and the Baltimore Orioles was carried live on
# the Orioles Radio Network, including affiliate WTOP in Washington, DC.
# During the game, play-by-play announcer Jim Hunter noted that
# "We'll be losing two hours of sleep...Cuba switched to Daylight Saving
# Time today." (The "two hour" remark referred to losing one hour of
# sleep on 1999-03-28 - when the announcers were in Cuba as it switched
# to DST - and one more hour on 1999-04-04 - when the announcers will have
# returned to Baltimore, which switches on that date.)
# From Steffen Thorsen (2013-11-11):
# DST start in Cuba in 2004 ... does not follow the same rules as the
# years before. The correct date should be Sunday 2004-03-28 00:00 ...
# https://web.archive.org/web/20040402060750/http://www.granma.cu/espanol/2004/marzo/sab27/reloj.html
# From Evert van der Veer via Steffen Thorsen (2004-10-28):
# Cuba is not going back to standard time this year.
# From Paul Eggert (2006-03-22):
# http://www.granma.cu/ingles/2004/septiembre/juev30/41medid-i.html
# says that it's due to a problem at the Antonio Guiteras
# thermoelectric plant, and says "This October there will be no return
# to normal hours (after daylight saving time)".
# For now, let's assume that it's a temporary measure.
# From Carlos A. Carnero Delgado (2005-11-12):
# This year (just like in 2004-2005) there's no change in time zone
# adjustment in Cuba. We will stay in daylight saving time:
# http://www.granma.cu/espanol/2005/noviembre/mier9/horario.html
# From Jesper Nørgaard Welen (2006-10-21):
# An article in GRANMA INTERNACIONAL claims that Cuba will end
# the 3 years of permanent DST next weekend, see
# http://www.granma.cu/ingles/2006/octubre/lun16/43horario.html
# "On Saturday night, October 28 going into Sunday, October 29, at 01:00,
# watches should be set back one hour - going back to 00:00 hours - returning
# to the normal schedule....
# From Paul Eggert (2007-03-02):
# <http://www.granma.cubaweb.cu/english/news/art89.html>, dated yesterday,
# says Cuban clocks will advance at midnight on March 10.
# For lack of better information, assume Cuba will use US rules,
# except that it switches at midnight standard time as usual.
#
# From Steffen Thorsen (2007-10-25):
# Carlos Alberto Fonseca Arauz informed me that Cuba will end DST one week
# earlier - on the last Sunday of October, just like in 2006.
#
# He supplied these references:
#
# http://www.prensalatina.com.mx/article.asp?ID=%7B4CC32C1B-A9F7-42FB-8A07-8631AFC923AF%7D&language=ES
# http://actualidad.terra.es/sociedad/articulo/cuba_llama_ahorrar_energia_cambio_1957044.htm
#
# From Alex Krivenyshev (2007-10-25):
# Here is also article from Granma (Cuba):
#
# Regirá el Horario Normal desde el próximo domingo 28 de octubre
# http://www.granma.cubaweb.cu/2007/10/24/nacional/artic07.html
#
# http://www.worldtimezone.com/dst_news/dst_news_cuba03.html
# From Arthur David Olson (2008-03-09):
# I'm in Maryland which is now observing United States Eastern Daylight
# Time. At 9:44 local time I used RealPlayer to listen to
# http://media.enet.cu/radioreloj
# a Cuban information station, and heard
# the time announced as "ocho cuarenta y cuatro" ("eight forty-four"),
# indicating that Cuba is still on standard time.
# From Steffen Thorsen (2008-03-12):
# It seems that Cuba will start DST on Sunday, 2007-03-16...
# It was announced yesterday, according to this source (in Spanish):
# http://www.nnc.cubaweb.cu/marzo-2008/cien-1-11-3-08.htm
#
# Some more background information is posted here:
# https://www.timeanddate.com/news/time/cuba-starts-dst-march-16.html
#
# The article also says that Cuba has been observing DST since 1963,
# while Shanks (and tzdata) has 1965 as the first date (except in the
# 1940's). Many other web pages in Cuba also claim that it has been
# observed since 1963, but with the exception of 1970 - an exception
# which is not present in tzdata/Shanks. So there is a chance we need to
# change some historic records as well.
#
# One example:
# http://www.radiohc.cu/espanol/noticias/mar07/11mar/hor.htm
# From Jesper Nørgaard Welen (2008-03-13):
# The Cuban time change has just been confirmed on the most authoritative
# web site, the Granma. Please check out
# http://www.granma.cubaweb.cu/2008/03/13/nacional/artic10.html
#
# Basically as expected after Steffen Thorsen's information, the change
# will take place midnight between Saturday and Sunday.
# From Arthur David Olson (2008-03-12):
# Assume Sun>=15 (third Sunday) going forward.
# From Alexander Krivenyshev (2009-03-04)
# According to the Radio Reloj - Cuba will start Daylight Saving Time on
# midnight between Saturday, March 07, 2009 and Sunday, March 08, 2009-
# not on midnight March 14 / March 15 as previously thought.
#
# http://www.worldtimezone.com/dst_news/dst_news_cuba05.html
# (in Spanish)
# From Arthur David Olson (2009-03-09)
# I listened over the Internet to
# http://media.enet.cu/readioreloj
# this morning; when it was 10:05 a. m. here in Bethesda, Maryland the
# the time was announced as "diez cinco" - the same time as here, indicating
# that has indeed switched to DST. Assume second Sunday from 2009 forward.
# From Steffen Thorsen (2011-03-08):
# Granma announced that Cuba is going to start DST on 2011-03-20 00:00:00
# this year. Nothing about the end date known so far (if that has
# changed at all).
#
# Source:
# http://granma.co.cu/2011/03/08/nacional/artic01.html
#
# Our info:
# https://www.timeanddate.com/news/time/cuba-starts-dst-2011.html
#
# From Steffen Thorsen (2011-10-30)
# Cuba will end DST two weeks later this year. Instead of going back
# tonight, it has been delayed to 2011-11-13 at 01:00.
#
# One source (Spanish)
# http://www.radioangulo.cu/noticias/cuba/17105-cuba-restablecera-el-horario-del-meridiano-de-greenwich.html
#
# Our page:
# https://www.timeanddate.com/news/time/cuba-time-changes-2011.html
#
# From Steffen Thorsen (2012-03-01)
# According to Radio Reloj, Cuba will start DST on Midnight between March
# 31 and April 1.
#
# Radio Reloj has the following info (Spanish):
# http://www.radioreloj.cu/index.php/noticias-radio-reloj/71-miscelaneas/7529-cuba-aplicara-el-horario-de-verano-desde-el-1-de-abril
#
# Our info on it:
# https://www.timeanddate.com/news/time/cuba-starts-dst-2012.html
# From Steffen Thorsen (2012-11-03):
# Radio Reloj and many other sources report that Cuba is changing back
# to standard time on 2012-11-04:
# http://www.radioreloj.cu/index.php/noticias-radio-reloj/36-nacionales/9961-regira-horario-normal-en-cuba-desde-el-domingo-cuatro-de-noviembre
# From Paul Eggert (2012-11-03):
# For now, assume the future rule is first Sunday in November.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Cuba 1928 only - Jun 10 0:00 1:00 D
Rule Cuba 1928 only - Oct 10 0:00 0 S
Rule Cuba 1940 1942 - Jun Sun>=1 0:00 1:00 D
Rule Cuba 1940 1942 - Sep Sun>=1 0:00 0 S
Rule Cuba 1945 1946 - Jun Sun>=1 0:00 1:00 D
Rule Cuba 1945 1946 - Sep Sun>=1 0:00 0 S
Rule Cuba 1965 only - Jun 1 0:00 1:00 D
Rule Cuba 1965 only - Sep 30 0:00 0 S
Rule Cuba 1966 only - May 29 0:00 1:00 D
Rule Cuba 1966 only - Oct 2 0:00 0 S
Rule Cuba 1967 only - Apr 8 0:00 1:00 D
Rule Cuba 1967 1968 - Sep Sun>=8 0:00 0 S
Rule Cuba 1968 only - Apr 14 0:00 1:00 D
Rule Cuba 1969 1977 - Apr lastSun 0:00 1:00 D
Rule Cuba 1969 1971 - Oct lastSun 0:00 0 S
Rule Cuba 1972 1974 - Oct 8 0:00 0 S
Rule Cuba 1975 1977 - Oct lastSun 0:00 0 S
Rule Cuba 1978 only - May 7 0:00 1:00 D
Rule Cuba 1978 1990 - Oct Sun>=8 0:00 0 S
Rule Cuba 1979 1980 - Mar Sun>=15 0:00 1:00 D
Rule Cuba 1981 1985 - May Sun>=5 0:00 1:00 D
Rule Cuba 1986 1989 - Mar Sun>=14 0:00 1:00 D
Rule Cuba 1990 1997 - Apr Sun>=1 0:00 1:00 D
Rule Cuba 1991 1995 - Oct Sun>=8 0:00s 0 S
Rule Cuba 1996 only - Oct 6 0:00s 0 S
Rule Cuba 1997 only - Oct 12 0:00s 0 S
Rule Cuba 1998 1999 - Mar lastSun 0:00s 1:00 D
Rule Cuba 1998 2003 - Oct lastSun 0:00s 0 S
Rule Cuba 2000 2003 - Apr Sun>=1 0:00s 1:00 D
Rule Cuba 2004 only - Mar lastSun 0:00s 1:00 D
Rule Cuba 2006 2010 - Oct lastSun 0:00s 0 S
Rule Cuba 2007 only - Mar Sun>=8 0:00s 1:00 D
Rule Cuba 2008 only - Mar Sun>=15 0:00s 1:00 D
Rule Cuba 2009 2010 - Mar Sun>=8 0:00s 1:00 D
Rule Cuba 2011 only - Mar Sun>=15 0:00s 1:00 D
Rule Cuba 2011 only - Nov 13 0:00s 0 S
Rule Cuba 2012 only - Apr 1 0:00s 1:00 D
Rule Cuba 2012 max - Nov Sun>=1 0:00s 0 S
Rule Cuba 2013 max - Mar Sun>=8 0:00s 1:00 D
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Havana -5:29:28 - LMT 1890
-5:29:36 - HMT 1925 Jul 19 12:00 # Havana MT
-5:00 Cuba C%sT
# Dominica
# See America/Port_of_Spain.
# Dominican Republic
# From Steffen Thorsen (2000-10-30):
# Enrique Morales reported to me that the Dominican Republic has changed the
# time zone to Eastern Standard Time as of Sunday 29 at 2 am....
# http://www.listin.com.do/antes/261000/republica/princi.html
# From Paul Eggert (2000-12-04):
# That URL (2000-10-26, in Spanish) says they planned to use US-style DST.
# From Rives McDow (2000-12-01):
# Dominican Republic changed its mind and presidential decree on Tuesday,
# November 28, 2000, with a new decree. On Sunday, December 3 at 1:00 AM the
# Dominican Republic will be reverting to 8 hours from the International Date
# Line, and will not be using DST in the foreseeable future. The reason they
# decided to use DST was to be in synch with Puerto Rico, who was also going
# to implement DST. When Puerto Rico didn't implement DST, the president
# decided to revert.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule DR 1966 only - Oct 30 0:00 1:00 EDT
Rule DR 1967 only - Feb 28 0:00 0 EST
Rule DR 1969 1973 - Oct lastSun 0:00 0:30 -0430
Rule DR 1970 only - Feb 21 0:00 0 EST
Rule DR 1971 only - Jan 20 0:00 0 EST
Rule DR 1972 1974 - Jan 21 0:00 0 EST
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Santo_Domingo -4:39:36 - LMT 1890
-4:40 - SDMT 1933 Apr 1 12:00 # S. Dom. MT
-5:00 DR %s 1974 Oct 27
-4:00 - AST 2000 Oct 29 2:00
-5:00 US E%sT 2000 Dec 3 1:00
-4:00 - AST
# El Salvador
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Salv 1987 1988 - May Sun>=1 0:00 1:00 D
Rule Salv 1987 1988 - Sep lastSun 0:00 0 S
# There are too many San Salvadors elsewhere, so use America/El_Salvador
# instead of America/San_Salvador.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/El_Salvador -5:56:48 - LMT 1921 # San Salvador
-6:00 Salv C%sT
# Grenada
# Guadeloupe
# St Barthélemy
# St Martin (French part)
# See America/Port_of_Spain.
# Guatemala
#
# From Gwillim Law (2006-04-22), after a heads-up from Oscar van Vlijmen:
# Diario Co Latino, at
# <http://www.diariocolatino.com/internacionales/detalles.asp?NewsID=8079>,
# says in an article dated 2006-04-19 that the Guatemalan government had
# decided on that date to advance official time by 60 minutes, to lessen the
# impact of the elevated cost of oil.... Daylight saving time will last from
# 2006-04-29 24:00 (Guatemalan standard time) to 2006-09-30 (time unspecified).
# From Paul Eggert (2006-06-22):
# The Ministry of Energy and Mines, press release CP-15/2006
# (2006-04-19), says DST ends at 24:00. See
# http://www.sieca.org.gt/Sitio_publico/Energeticos/Doc/Medidas/Cambio_Horario_Nac_190406.pdf
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Guat 1973 only - Nov 25 0:00 1:00 D
Rule Guat 1974 only - Feb 24 0:00 0 S
Rule Guat 1983 only - May 21 0:00 1:00 D
Rule Guat 1983 only - Sep 22 0:00 0 S
Rule Guat 1991 only - Mar 23 0:00 1:00 D
Rule Guat 1991 only - Sep 7 0:00 0 S
Rule Guat 2006 only - Apr 30 0:00 1:00 D
Rule Guat 2006 only - Oct 1 0:00 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Guatemala -6:02:04 - LMT 1918 Oct 5
-6:00 Guat C%sT
# Haiti
# From Gwillim Law (2005-04-15):
# Risto O. Nykänen wrote me that Haiti is now on DST.
# I searched for confirmation, and I found a press release
# on the Web page of the Haitian Consulate in Chicago (2005-03-31),
# <http://www.haitianconsulate.org/time.doc>. Translated from French, it says:
#
# "The Prime Minister's Communication Office notifies the public in general
# and the press in particular that, following a decision of the Interior
# Ministry and the Territorial Collectivities [I suppose that means the
# provinces], Haiti will move to Eastern Daylight Time in the night from next
# Saturday the 2nd to Sunday the 3rd.
#
# "Consequently, the Prime Minister's Communication Office wishes to inform
# the population that the country's clocks will be set forward one hour
# starting at midnight. This provision will hold until the last Saturday in
# October 2005.
#
# "Port-au-Prince, March 31, 2005"
#
# From Steffen Thorsen (2006-04-04):
# I have been informed by users that Haiti observes DST this year like
# last year, so the current "only" rule for 2005 might be changed to a
# "max" rule or to last until 2006. (Who knows if they will observe DST
# next year or if they will extend their DST like US/Canada next year).
#
# I have found this article about it (in French):
# http://www.haitipressnetwork.com/news.cfm?articleID=7612
#
# The reason seems to be an energy crisis.
# From Stephen Colebourne (2007-02-22):
# Some IATA info: Haiti won't be having DST in 2007.
# From Steffen Thorsen (2012-03-11):
# According to several news sources, Haiti will observe DST this year,
# apparently using the same start and end date as USA/Canada.
# So this means they have already changed their time.
#
# http://www.alterpresse.org/spip.php?article12510
# http://radiovision2000haiti.net/home/?p=13253
#
# From Arthur David Olson (2012-03-11):
# The alterpresse.org source seems to show a US-style leap from 2:00 a.m. to
# 3:00 a.m. rather than the traditional Haitian jump at midnight.
# Assume a US-style fall back as well.
# From Steffen Thorsen (2013-03-10):
# It appears that Haiti is observing DST this year as well, same rules
# as US/Canada. They did it last year as well, and it looks like they
# are going to observe DST every year now...
#
# http://radiovision2000haiti.net/public/haiti-avis-changement-dheure-dimanche/
# http://www.canalplushaiti.net/?p=6714
# From Steffen Thorsen (2016-03-12):
# Jean Antoine, editor of www.haiti-reference.com informed us that Haiti
# are not going on DST this year. Several other resources confirm this: ...
# https://www.radiotelevisioncaraibes.com/presse/heure_d_t_pas_de_changement_d_heure_pr_vu_pour_cet_ann_e.html
# https://www.vantbefinfo.com/changement-dheure-pas-pour-haiti/
# http://news.anmwe.com/haiti-lheure-nationale-ne-sera-ni-avancee-ni-reculee-cette-annee/
# From Steffen Thorsen (2017-03-12):
# We have received 4 mails from different people telling that Haiti
# has started DST again today, and this source seems to confirm that,
# I have not been able to find a more authoritative source:
# https://www.haitilibre.com/en/news-20319-haiti-notices-time-change-in-haiti.html
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Haiti 1983 only - May 8 0:00 1:00 D
Rule Haiti 1984 1987 - Apr lastSun 0:00 1:00 D
Rule Haiti 1983 1987 - Oct lastSun 0:00 0 S
# Shanks & Pottenger say AT is 2:00, but IATA SSIM (1991/1997) says 1:00s.
# Go with IATA.
Rule Haiti 1988 1997 - Apr Sun>=1 1:00s 1:00 D
Rule Haiti 1988 1997 - Oct lastSun 1:00s 0 S
Rule Haiti 2005 2006 - Apr Sun>=1 0:00 1:00 D
Rule Haiti 2005 2006 - Oct lastSun 0:00 0 S
Rule Haiti 2012 2015 - Mar Sun>=8 2:00 1:00 D
Rule Haiti 2012 2015 - Nov Sun>=1 2:00 0 S
Rule Haiti 2017 max - Mar Sun>=8 2:00 1:00 D
Rule Haiti 2017 max - Nov Sun>=1 2:00 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Port-au-Prince -4:49:20 - LMT 1890
-4:49 - PPMT 1917 Jan 24 12:00 # P-a-P MT
-5:00 Haiti E%sT
# Honduras
# Shanks & Pottenger say 1921 Jan 1; go with Whitman's more precise Apr 1.
# From Paul Eggert (2006-05-05):
# worldtimezone.com reports a 2006-05-02 Spanish-language AP article
# saying Honduras will start using DST midnight Saturday, effective 4
# months until September. La Tribuna reported today
# <http://www.latribuna.hn/99299.html> that Manuel Zelaya, the president
# of Honduras, refused to back down on this.
# From Jesper Nørgaard Welen (2006-08-08):
# It seems that Honduras has returned from DST to standard time this Monday at
# 00:00 hours (prolonging Sunday to 25 hours duration).
# http://www.worldtimezone.com/dst_news/dst_news_honduras04.html
# From Paul Eggert (2006-08-08):
# Also see Diario El Heraldo, The country returns to standard time (2006-08-08).
# http://www.elheraldo.hn/nota.php?nid=54941&sec=12
# It mentions executive decree 18-2006.
# From Steffen Thorsen (2006-08-17):
# Honduras will observe DST from 2007 to 2009, exact dates are not
# published, I have located this authoritative source:
# http://www.presidencia.gob.hn/noticia.aspx?nId=47
# From Steffen Thorsen (2007-03-30):
# http://www.laprensahn.com/pais_nota.php?id04962=7386
# So it seems that Honduras will not enter DST this year....
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Hond 1987 1988 - May Sun>=1 0:00 1:00 D
Rule Hond 1987 1988 - Sep lastSun 0:00 0 S
Rule Hond 2006 only - May Sun>=1 0:00 1:00 D
Rule Hond 2006 only - Aug Mon>=1 0:00 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Tegucigalpa -5:48:52 - LMT 1921 Apr
-6:00 Hond C%sT
#
# Great Swan I ceded by US to Honduras in 1972
# Jamaica
# Shanks & Pottenger give -5:07:12, but Milne records -5:07:10.41 from an
# unspecified official document, and says "This time is used throughout the
# island". Go with Milne. Round to the nearest second as required by zic.
#
# Shanks & Pottenger give April 28 for the 1974 spring-forward transition, but
# Lance Neita writes that Prime Minister Michael Manley decreed it January 5.
# Assume Neita meant Jan 6 02:00, the same as the US. Neita also writes that
# Manley's supporters associated this act with Manley's nickname "Joshua"
# (recall that in the Bible the sun stood still at Joshua's request),
# and with the Rod of Correction which Manley said he had received from
# Haile Selassie, Emperor of Ethiopia. See:
# Neita L. The politician in all of us. Jamaica Observer 2014-09-20
# http://www.jamaicaobserver.com/columns/The-politician-in-all-of-us_17573647
#
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Jamaica -5:07:10 - LMT 1890 # Kingston
-5:07:10 - KMT 1912 Feb # Kingston Mean Time
-5:00 - EST 1974
-5:00 US E%sT 1984
-5:00 - EST
# Martinique
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Martinique -4:04:20 - LMT 1890 # Fort-de-France
-4:04:20 - FFMT 1911 May # Fort-de-France MT
-4:00 - AST 1980 Apr 6
-4:00 1:00 ADT 1980 Sep 28
-4:00 - AST
# Montserrat
# See America/Port_of_Spain.
# Nicaragua
#
# This uses Shanks & Pottenger for times before 2005.
#
# From Steffen Thorsen (2005-04-12):
# I've got reports from 8 different people that Nicaragua just started
# DST on Sunday 2005-04-10, in order to save energy because of
# expensive petroleum. The exact end date for DST is not yet
# announced, only "September" but some sites also say "mid-September".
# Some background information is available on the President's official site:
# http://www.presidencia.gob.ni/Presidencia/Files_index/Secretaria/Notas%20de%20Prensa/Presidente/2005/ABRIL/Gobierno-de-nicaragua-adelanta-hora-oficial-06abril.htm
# The Decree, no 23-2005 is available here:
# http://www.presidencia.gob.ni/buscador_gaceta/BD/DECRETOS/2005/Decreto%2023-2005%20Se%20adelanta%20en%20una%20hora%20en%20todo%20el%20territorio%20nacional%20apartir%20de%20las%2024horas%20del%2009%20de%20Abril.pdf
#
# From Paul Eggert (2005-05-01):
# The decree doesn't say anything about daylight saving, but for now let's
# assume that it is daylight saving....
#
# From Gwillim Law (2005-04-21):
# The Associated Press story on the time change, which can be found at
# http://www.lapalmainteractivo.com/guias/content/gen/ap/America_Latina/AMC_GEN_NICARAGUA_HORA.html
# and elsewhere, says (fifth paragraph, translated from Spanish): "The last
# time that a change of clocks was applied to save energy was in the year 2000
# during the Arnoldo Alemán administration."...
# The northamerica file says that Nicaragua has been on UTC-6 continuously
# since December 1998. I wasn't able to find any details of Nicaraguan time
# changes in 2000. Perhaps a note could be added to the northamerica file, to
# the effect that we have indirect evidence that DST was observed in 2000.
#
# From Jesper Nørgaard Welen (2005-11-02):
# Nicaragua left DST the 2005-10-02 at 00:00 (local time).
# http://www.presidencia.gob.ni/presidencia/files_index/secretaria/comunicados/2005/septiembre/26septiembre-cambio-hora.htm
# (2005-09-26)
#
# From Jesper Nørgaard Welen (2006-05-05):
# http://www.elnuevodiario.com.ni/2006/05/01/nacionales/18410
# (my informal translation)
# By order of the president of the republic, Enrique Bolaños, Nicaragua
# advanced by sixty minutes their official time, yesterday at 2 in the
# morning, and will stay that way until 30th of September.
#
# From Jesper Nørgaard Welen (2006-09-30):
# http://www.presidencia.gob.ni/buscador_gaceta/BD/DECRETOS/2006/D-063-2006P-PRN-Cambio-Hora.pdf
# My informal translation runs:
# The natural sun time is restored in all the national territory, in that the
# time is returned one hour at 01:00 am of October 1 of 2006.
#
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Nic 1979 1980 - Mar Sun>=16 0:00 1:00 D
Rule Nic 1979 1980 - Jun Mon>=23 0:00 0 S
Rule Nic 2005 only - Apr 10 0:00 1:00 D
Rule Nic 2005 only - Oct Sun>=1 0:00 0 S
Rule Nic 2006 only - Apr 30 2:00 1:00 D
Rule Nic 2006 only - Oct Sun>=1 1:00 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Managua -5:45:08 - LMT 1890
-5:45:12 - MMT 1934 Jun 23 # Managua Mean Time?
-6:00 - CST 1973 May
-5:00 - EST 1975 Feb 16
-6:00 Nic C%sT 1992 Jan 1 4:00
-5:00 - EST 1992 Sep 24
-6:00 - CST 1993
-5:00 - EST 1997
-6:00 Nic C%sT
# Panama
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Panama -5:18:08 - LMT 1890
-5:19:36 - CMT 1908 Apr 22 # Colón Mean Time
-5:00 - EST
Link America/Panama America/Cayman
# Puerto Rico
# There are too many San Juans elsewhere, so we'll use 'Puerto_Rico'.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Puerto_Rico -4:24:25 - LMT 1899 Mar 28 12:00 # San Juan
-4:00 - AST 1942 May 3
-4:00 US A%sT 1946
-4:00 - AST
# St Kitts-Nevis
# St Lucia
# See America/Port_of_Spain.
# St Pierre and Miquelon
# There are too many St Pierres elsewhere, so we'll use 'Miquelon'.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Miquelon -3:44:40 - LMT 1911 May 15 # St Pierre
-4:00 - AST 1980 May
-3:00 - -03 1987
-3:00 Canada -03/-02
# St Vincent and the Grenadines
# See America/Port_of_Spain.
# Turks and Caicos
#
# From Chris Dunn in
# https://bugs.debian.org/415007
# (2007-03-15): In the Turks & Caicos Islands (America/Grand_Turk) the
# daylight saving dates for time changes have been adjusted to match
# the recent U.S. change of dates.
#
# From Brian Inglis (2007-04-28):
# http://www.turksandcaicos.tc/calendar/index.htm [2007-04-26]
# there is an entry for Nov 4 "Daylight Savings Time Ends 2007" and three
# rows before that there is an out of date entry for Oct:
# "Eastern Standard Times Begins 2007
# Clocks are set back one hour at 2:00 a.m. local Daylight Saving Time"
# indicating that the normal ET rules are followed.
#
# From Paul Eggert (2014-08-19):
# The 2014-08-13 Cabinet meeting decided to stay on UT -04 year-round. See:
# http://tcweeklynews.com/daylight-savings-time-to-be-maintained-p5353-127.htm
# Model this as a switch from EST/EDT to AST ...
# From Chris Walton (2014-11-04):
# ... the TCI government appears to have delayed the switch to
# "permanent daylight saving time" by one year....
# http://tcweeklynews.com/time-change-to-go-ahead-this-november-p5437-127.htm
#
# From the Turks & Caicos Cabinet (2017-07-20), heads-up from Steffen Thorsen:
# ... agreed to the reintroduction in TCI of Daylight Saving Time (DST)
# during the summer months and Standard Time, also known as Local
# Time, during the winter months with effect from April 2018 ...
# https://www.gov.uk/government/news/turks-and-caicos-post-cabinet-meeting-statement--3
#
# From Paul Eggert (2017-08-26):
# The date of effect of the spring 2018 change appears to be March 11,
# which makes more sense. See: Hamilton D. Time change back
# by March 2018 for TCI. Magnetic Media. 2017-08-25.
# http://magneticmediatv.com/2017/08/time-change-back-by-march-2018-for-tci/
#
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Grand_Turk -4:44:32 - LMT 1890
-5:07:10 - KMT 1912 Feb # Kingston Mean Time
-5:00 - EST 1979
-5:00 US E%sT 2015 Nov Sun>=1 2:00
-4:00 - AST 2018 Mar 11 3:00
-5:00 US E%sT
# British Virgin Is
# Virgin Is
# See America/Port_of_Spain.
# Local Variables:
# coding: utf-8
# End:
Index: stable/12/contrib/tzdata/southamerica
===================================================================
--- stable/12/contrib/tzdata/southamerica (revision 352352)
+++ stable/12/contrib/tzdata/southamerica (revision 352353)
@@ -1,1966 +1,1965 @@
# tzdb data for South America and environs
# This file is in the public domain, so clarified as of
# 2009-05-17 by Arthur David Olson.
# This file is by no means authoritative; if you think you know better,
# go ahead and edit the file (and please send any changes to
# tz@iana.org for general use in the future). For more, please see
# the file CONTRIBUTING in the tz distribution.
# From Paul Eggert (2016-12-05):
#
# Unless otherwise specified, the source for data through 1990 is:
# Thomas G. Shanks and Rique Pottenger, The International Atlas (6th edition),
# San Diego: ACS Publications, Inc. (2003).
# Unfortunately this book contains many errors and cites no sources.
#
# Many years ago Gwillim Law wrote that a good source
# for time zone data was the International Air Transport
# Association's Standard Schedules Information Manual (IATA SSIM),
# published semiannually. Law sent in several helpful summaries
# of the IATA's data after 1990. Except where otherwise noted,
# IATA SSIM is the source for entries after 1990.
#
# For data circa 1899, a common source is:
# Milne J. Civil time. Geogr J. 1899 Feb;13(2):173-94.
# https://www.jstor.org/stable/1774359
#
# These tables use numeric abbreviations like -03 and -0330 for
# integer hour and minute UT offsets. Although earlier editions used
# alphabetic time zone abbreviations, these abbreviations were
# invented and did not reflect common practice.
###############################################################################
###############################################################################
# Argentina
# From Bob Devine (1988-01-28):
# Argentina: first Sunday in October to first Sunday in April since 1976.
# Double Summer time from 1969 to 1974. Switches at midnight.
# From U. S. Naval Observatory (1988-01-19):
# ARGENTINA 3 H BEHIND UTC
# From Hernan G. Otero (1995-06-26):
# I am sending modifications to the Argentine time zone table...
# AR was chosen because they are the ISO letters that represent Argentina.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Arg 1930 only - Dec 1 0:00 1:00 -
Rule Arg 1931 only - Apr 1 0:00 0 -
Rule Arg 1931 only - Oct 15 0:00 1:00 -
Rule Arg 1932 1940 - Mar 1 0:00 0 -
Rule Arg 1932 1939 - Nov 1 0:00 1:00 -
Rule Arg 1940 only - Jul 1 0:00 1:00 -
Rule Arg 1941 only - Jun 15 0:00 0 -
Rule Arg 1941 only - Oct 15 0:00 1:00 -
Rule Arg 1943 only - Aug 1 0:00 0 -
Rule Arg 1943 only - Oct 15 0:00 1:00 -
Rule Arg 1946 only - Mar 1 0:00 0 -
Rule Arg 1946 only - Oct 1 0:00 1:00 -
Rule Arg 1963 only - Oct 1 0:00 0 -
Rule Arg 1963 only - Dec 15 0:00 1:00 -
Rule Arg 1964 1966 - Mar 1 0:00 0 -
Rule Arg 1964 1966 - Oct 15 0:00 1:00 -
Rule Arg 1967 only - Apr 2 0:00 0 -
Rule Arg 1967 1968 - Oct Sun>=1 0:00 1:00 -
Rule Arg 1968 1969 - Apr Sun>=1 0:00 0 -
Rule Arg 1974 only - Jan 23 0:00 1:00 -
Rule Arg 1974 only - May 1 0:00 0 -
Rule Arg 1988 only - Dec 1 0:00 1:00 -
#
# From Hernan G. Otero (1995-06-26):
# These corrections were contributed by InterSoft Argentina S.A.,
# obtaining the data from the:
# Talleres de Hidrografía Naval Argentina
# (Argentine Naval Hydrography Institute)
Rule Arg 1989 1993 - Mar Sun>=1 0:00 0 -
Rule Arg 1989 1992 - Oct Sun>=15 0:00 1:00 -
#
# From Hernan G. Otero (1995-06-26):
# From this moment on, the law that mandated the daylight saving
# time corrections was derogated and no more modifications
# to the time zones (for daylight saving) are now made.
#
# From Rives McDow (2000-01-10):
# On October 3, 1999, 0:00 local, Argentina implemented daylight savings time,
# which did not result in the switch of a time zone, as they stayed 9 hours
# from the International Date Line.
Rule Arg 1999 only - Oct Sun>=1 0:00 1:00 -
# From Paul Eggert (2007-12-28):
# DST was set to expire on March 5, not March 3, but since it was converted
# to standard time on March 3 it's more convenient for us to pretend that
# it ended on March 3.
Rule Arg 2000 only - Mar 3 0:00 0 -
#
# From Peter Gradelski via Steffen Thorsen (2000-03-01):
# We just checked with our São Paulo office and they say the government of
# Argentina decided not to become one of the countries that go on or off DST.
# So Buenos Aires should be -3 hours from GMT at all times.
#
# From Fabián L. Arce Jofré (2000-04-04):
# The law that claimed DST for Argentina was derogated by President Fernando
# de la Rúa on March 2, 2000, because it would make people spend more energy
# in the winter time, rather than less. The change took effect on March 3.
#
# From Mariano Absatz (2001-06-06):
# one of the major newspapers here in Argentina said that the 1999
# Timezone Law (which never was effectively applied) will (would?) be
# in effect.... The article is at
# http://ar.clarin.com/diario/2001-06-06/e-01701.htm
# ... The Law itself is "Ley No. 25155", sanctioned on 1999-08-25, enacted
# 1999-09-17, and published 1999-09-21. The official publication is at:
# http://www.boletin.jus.gov.ar/BON/Primera/1999/09-Septiembre/21/PDF/BO21-09-99LEG.PDF
# Regretfully, you have to subscribe (and pay) for the on-line version....
#
# (2001-06-12):
# the timezone for Argentina will not change next Sunday.
# Apparently it will do so on Sunday 24th....
# http://ar.clarin.com/diario/2001-06-12/s-03501.htm
#
# (2001-06-25):
# Last Friday (yes, the last working day before the date of the change), the
# Senate annulled the 1999 law that introduced the changes later postponed.
# http://www.clarin.com.ar/diario/2001-06-22/s-03601.htm
# It remains the vote of the Deputies..., but it will be the same....
# This kind of things had always been done this way in Argentina.
# We are still -03:00 all year round in all of the country.
#
# From Steffen Thorsen (2007-12-21):
# A user (Leonardo Chaim) reported that Argentina will adopt DST....
# all of the country (all Zone-entries) are affected. News reports like
# http://www.lanacion.com.ar/opinion/nota.asp?nota_id=973037 indicate
# that Argentina will use DST next year as well, from October to
# March, although exact rules are not given.
#
# From Jesper Nørgaard Welen (2007-12-26)
# The last hurdle of Argentina DST is over, the proposal was approved in
# the lower chamber too (Diputados) with a vote 192 for and 2 against.
# By the way thanks to Mariano Absatz and Daniel Mario Vega for the link to
# the original scanned proposal, where the dates and the zero hours are
# clear and unambiguous...This is the article about final approval:
# http://www.lanacion.com.ar/politica/nota.asp?nota_id=973996
#
# From Paul Eggert (2007-12-22):
# For dates after mid-2008, the following rules are my guesses and
# are quite possibly wrong, but are more likely than no DST at all.
# From Alexander Krivenyshev (2008-09-05):
# As per message from Carlos Alberto Fonseca Arauz (Nicaragua),
# Argentina will start DST on Sunday October 19, 2008.
#
# http://www.worldtimezone.com/dst_news/dst_news_argentina03.html
# http://www.impulsobaires.com.ar/nota.php?id=57832 (in spanish)
# From Juan Manuel Docile in https://bugs.gentoo.org/240339 (2008-10-07)
# via Rodrigo Severo:
# Argentinian law No. 25.155 is no longer valid.
# http://www.infoleg.gov.ar/infolegInternet/anexos/60000-64999/60036/norma.htm
# The new one is law No. 26.350
# http://www.infoleg.gov.ar/infolegInternet/anexos/135000-139999/136191/norma.htm
# So there is no summer time in Argentina for now.
# From Mariano Absatz (2008-10-20):
# Decree 1693/2008 applies Law 26.350 for the summer 2008/2009 establishing DST
# in Argentina from 2008-10-19 until 2009-03-15.
# http://www.boletinoficial.gov.ar/Bora.Portal/CustomControls/PdfContent.aspx?fp=16102008&pi=3&pf=4&s=0&sec=01
#
# Decree 1705/2008 excepting 12 Provinces from applying DST in the summer
# 2008/2009: Catamarca, La Rioja, Mendoza, Salta, San Juan, San Luis, La
# Pampa, Neuquén, Rio Negro, Chubut, Santa Cruz and Tierra del Fuego
# http://www.boletinoficial.gov.ar/Bora.Portal/CustomControls/PdfContent.aspx?fp=17102008&pi=1&pf=1&s=0&sec=01
#
# Press release 235 dated Saturday October 18th, from the Government of the
# Province of Jujuy saying it will not apply DST either (even when it was not
# included in Decree 1705/2008).
# http://www.jujuy.gov.ar/index2/partes_prensa/18_10_08/235-181008.doc
# From fullinet (2009-10-18):
# As announced in
# http://www.argentina.gob.ar/argentina/portal/paginas.dhtml?pagina=356
# (an official .gob.ar) under title: "Sin Cambio de Hora"
# (English: "No hour change").
#
# "Por el momento, el Gobierno Nacional resolvió no modificar la hora
# oficial, decisión que estaba en estudio para su implementación el
# domingo 18 de octubre. Desde el Ministerio de Planificación se anunció
# que la Argentina hoy, en estas condiciones meteorológicas, no necesita
# la modificación del huso horario, ya que 2009 nos encuentra con
# crecimiento en la producción y distribución energética."
Rule Arg 2007 only - Dec 30 0:00 1:00 -
Rule Arg 2008 2009 - Mar Sun>=15 0:00 0 -
Rule Arg 2008 only - Oct Sun>=15 0:00 1:00 -
# From Mariano Absatz (2004-05-21):
# Today it was officially published that the Province of Mendoza is changing
# its timezone this winter... starting tomorrow night....
# http://www.gobernac.mendoza.gov.ar/boletin/pdf/20040521-27158-normas.pdf
# From Paul Eggert (2004-05-24):
# It's Law No. 7,210. This change is due to a public power emergency, so for
# now we'll assume it's for this year only.
#
# From Paul Eggert (2018-01-31):
# Hora de verano para la República Argentina
# http://buenasiembra.com.ar/esoterismo/astrologia/hora-de-verano-de-la-republica-argentina-27.html
# says that standard time in Argentina from 1894-10-31
# to 1920-05-01 was -4:16:48.25. Go with this more-precise value
# over Shanks & Pottenger. It is upward compatible with Milne, who
# says Córdoba time was -4:16:48.2.
#
# From Mariano Absatz (2004-06-05):
# These media articles from a major newspaper mostly cover the current state:
# http://www.lanacion.com.ar/04/05/27/de_604825.asp
# http://www.lanacion.com.ar/04/05/28/de_605203.asp
#
# The following eight (8) provinces pulled clocks back to UTC-04:00 at
# midnight Monday May 31st. (that is, the night between 05/31 and 06/01).
# Apparently, all nine provinces would go back to UTC-03:00 at the same
# time in October 17th.
#
# Catamarca, Chubut, La Rioja, San Juan, San Luis, Santa Cruz,
# Tierra del Fuego, Tucumán.
#
# From Mariano Absatz (2004-06-14):
# ... this weekend, the Province of Tucumán decided it'd go back to UTC-03:00
# yesterday midnight (that is, at 24:00 Saturday 12th), since the people's
# annoyance with the change is much higher than the power savings obtained....
#
# From Gwillim Law (2004-06-14):
# http://www.lanacion.com.ar/04/06/10/de_609078.asp ...
# "The time change in Tierra del Fuego was a conflicted decision from
# the start. The government had decreed that the measure would take
# effect on June 1, but a normative error forced the new time to begin
# three days earlier, from a Saturday to a Sunday....
# Our understanding was that the change was originally scheduled to take place
# on June 1 at 00:00 in Chubut, Santa Cruz, Tierra del Fuego (and some other
# provinces). Sunday was May 30, only two days earlier. So the article
# contains a contradiction. I would give more credence to the Saturday/Sunday
# date than the "three days earlier" phrase, and conclude that Tierra del
# Fuego set its clocks back at 2004-05-30 00:00.
#
# From Steffen Thorsen (2004-10-05):
# The previous law 7210 which changed the province of Mendoza's time zone
# back in May have been modified slightly in a new law 7277, which set the
# new end date to 2004-09-26 (original date was 2004-10-17).
# http://www.gobernac.mendoza.gov.ar/boletin/pdf/20040924-27244-normas.pdf
#
# From Mariano Absatz (2004-10-05):
# San Juan changed from UTC-03:00 to UTC-04:00 at midnight between
# Sunday, May 30th and Monday, May 31st. It changed back to UTC-03:00
# at midnight between Saturday, July 24th and Sunday, July 25th....
# http://www.sanjuan.gov.ar/prensa/archivo/000329.html
# http://www.sanjuan.gov.ar/prensa/archivo/000426.html
# http://www.sanjuan.gov.ar/prensa/archivo/000441.html
# From Alex Krivenyshev (2008-01-17):
# Here are articles that Argentina Province San Luis is planning to end DST
# as earlier as upcoming Monday January 21, 2008 or February 2008:
#
# Provincia argentina retrasa reloj y marca diferencia con resto del país
# (Argentine Province delayed clock and mark difference with the rest of the
# country)
# http://cl.invertia.com/noticias/noticia.aspx?idNoticia=200801171849_EFE_ET4373&idtel
#
# Es inminente que en San Luis atrasen una hora los relojes
# (It is imminent in San Luis clocks one hour delay)
# https://www.lagaceta.com.ar/nota/253414/Economia/Es-inminente-que-en-San-Luis-atrasen-una-hora-los-relojes.html
# http://www.worldtimezone.com/dst_news/dst_news_argentina02.html
# From Jesper Nørgaard Welen (2008-01-18):
# The page of the San Luis provincial government
# http://www.sanluis.gov.ar/notas.asp?idCanal=0&id=22812
# confirms what Alex Krivenyshev has earlier sent to the tz
# emailing list about that San Luis plans to return to standard
# time much earlier than the rest of the country. It also
# confirms that upon request the provinces San Juan and Mendoza
# refused to follow San Luis in this change.
#
# The change is supposed to take place Monday the 21st at 0:00
# hours. As far as I understand it if this goes ahead, we need
# a new timezone for San Luis (although there are also documented
# independent changes in the southamerica file of San Luis in
# 1990 and 1991 which has not been confirmed).
# From Jesper Nørgaard Welen (2008-01-25):
# Unfortunately the below page has become defunct, about the San Luis
# time change. Perhaps because it now is part of a group of pages "Most
# important pages of 2008."
#
# You can use
# http://www.sanluis.gov.ar/notas.asp?idCanal=8141&id=22834
# instead it seems. Or use "Buscador" from the main page of the San Luis
# government, and fill in "huso" and click OK, and you will get 3 pages
# from which the first one is identical to the above.
# From Mariano Absatz (2008-01-28):
# I can confirm that the Province of San Luis (and so far only that
# province) decided to go back to UTC-3 effective midnight Jan 20th 2008
# (that is, Monday 21st at 0:00 is the time the clocks were delayed back
# 1 hour), and they intend to keep UTC-3 as their timezone all year round
# (that is, unless they change their mind any minute now).
#
# So we'll have to add yet another city to 'southamerica' (I think San
# Luis city is the mos populated city in the Province, so it'd be
# America/Argentina/San_Luis... of course I can't remember if San Luis's
# history of particular changes goes along with Mendoza or San Juan :-(
# (I only remember not being able to collect hard facts about San Luis
# back in 2004, when these provinces changed to UTC-4 for a few days, I
# mailed them personally and never got an answer).
# From Paul Eggert (2014-08-12):
# Unless otherwise specified, data entries are from Shanks & Pottenger through
# 1992, from the IATA otherwise. As noted below, Shanks & Pottenger say that
# America/Cordoba split into 6 subregions during 1991/1992, one of which
# was America/San_Luis, but we haven't verified this yet so for now we'll
# keep America/Cordoba a single region rather than splitting it into the
# other 5 subregions.
# From Mariano Absatz (2009-03-13):
# Yesterday (with our usual 2-day notice) the Province of San Luis
# decided that next Sunday instead of "staying" @utc-03:00 they will go
# to utc-04:00 until the second Saturday in October...
#
# The press release is at
# http://www.sanluis.gov.ar/SL/Paginas/NoticiaDetalle.asp?TemaId=1&InfoPrensaId=3102
# (I couldn't find the decree, but www.sanluis.gov.ar
# is the official page for the Province Government.)
#
# There's also a note in only one of the major national papers ...
# http://www.lanacion.com.ar/nota.asp?nota_id=1107912
#
# The press release says [quick and dirty translation]:
# ... announced that next Sunday, at 00:00, Puntanos (the San Luis
# inhabitants) will have to turn back one hour their clocks
#
# Since then, San Luis will establish its own Province timezone. Thus,
# during 2009, this timezone change will run from 00:00 the third Sunday
# in March until 24:00 of the second Saturday in October.
# From Mariano Absatz (2009-10-16):
# ...the Province of San Luis is a case in itself.
#
# The Law at
# http://www.diputadossanluis.gov.ar/diputadosasp/paginas/verNorma.asp?NormaID=276
# is ambiguous because establishes a calendar from the 2nd Sunday in
# October at 0:00 thru the 2nd Saturday in March at 24:00 and the
# complement of that starting on the 2nd Sunday of March at 0:00 and
# ending on the 2nd Saturday of March at 24:00.
#
# This clearly breaks every time the 1st of March or October is a Sunday.
#
# IMHO, the "spirit of the Law" is to make the changes at 0:00 on the 2nd
# Sunday of October and March.
#
# The problem is that the changes in the rest of the Provinces that did
# change in 2007/2008, were made according to the Federal Law and Decrees
# that did so on the 3rd Sunday of October and March.
#
# In fact, San Luis actually switched from UTC-4 to UTC-3 last Sunday
# (October 11th) at 0:00.
#
# So I guess a new set of rules, besides "Arg", must be made and the last
# America/Argentina/San_Luis entries should change to use these...
# ...
# From Alexander Krivenyshev (2010-04-09):
# According to news reports from El Diario de la República Province San
# Luis, Argentina (standard time UTC-04) will keep Daylight Saving Time
# after April 11, 2010 - will continue to have same time as rest of
# Argentina (UTC-3) (no DST).
#
# Confirmaron la prórroga del huso horario de verano (Spanish)
# http://www.eldiariodelarepublica.com/index.php?option=com_content&task=view&id=29383&Itemid=9
# or (some English translation):
# http://www.worldtimezone.com/dst_news/dst_news_argentina08.html
# From Mariano Absatz (2010-04-12):
# yes...I can confirm this...and given that San Luis keeps calling
# UTC-03:00 "summer time", we should't just let San Luis go back to "Arg"
# rules...San Luis is still using "Western ARgentina Time" and it got
# stuck on Summer daylight savings time even though the summer is over.
# From Paul Eggert (2018-01-23):
# Perhaps San Luis operates on the legal fiction that it is at -04
# with perpetual daylight saving time, but ordinary usage typically seems to
# just say it's at -03; see, for example,
# https://es.wikipedia.org/wiki/Hora_oficial_argentina
# We've documented similar situations as being plain changes to
# standard time, so let's do that here too. This does not change UTC
# offsets, only tm_isdst and the time zone abbreviations. One minor
# plus is that this silences a zic complaint that there's no POSIX TZ
# setting for timestamps past 2038.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
#
# Buenos Aires (BA), Capital Federal (CF),
Zone America/Argentina/Buenos_Aires -3:53:48 - LMT 1894 Oct 31
-4:16:48 - CMT 1920 May # Córdoba Mean Time
-4:00 - -04 1930 Dec
-4:00 Arg -04/-03 1969 Oct 5
-3:00 Arg -03/-02 1999 Oct 3
-4:00 Arg -04/-03 2000 Mar 3
-3:00 Arg -03/-02
#
# Córdoba (CB), Santa Fe (SF), Entre Ríos (ER), Corrientes (CN), Misiones (MN),
# Chaco (CC), Formosa (FM), Santiago del Estero (SE)
#
# Shanks & Pottenger also make the following claims, which we haven't verified:
# - Formosa switched to -3:00 on 1991-01-07.
# - Misiones switched to -3:00 on 1990-12-29.
# - Chaco switched to -3:00 on 1991-01-04.
# - Santiago del Estero switched to -4:00 on 1991-04-01,
# then to -3:00 on 1991-04-26.
#
Zone America/Argentina/Cordoba -4:16:48 - LMT 1894 Oct 31
-4:16:48 - CMT 1920 May
-4:00 - -04 1930 Dec
-4:00 Arg -04/-03 1969 Oct 5
-3:00 Arg -03/-02 1991 Mar 3
-4:00 - -04 1991 Oct 20
-3:00 Arg -03/-02 1999 Oct 3
-4:00 Arg -04/-03 2000 Mar 3
-3:00 Arg -03/-02
#
# Salta (SA), La Pampa (LP), Neuquén (NQ), Rio Negro (RN)
Zone America/Argentina/Salta -4:21:40 - LMT 1894 Oct 31
-4:16:48 - CMT 1920 May
-4:00 - -04 1930 Dec
-4:00 Arg -04/-03 1969 Oct 5
-3:00 Arg -03/-02 1991 Mar 3
-4:00 - -04 1991 Oct 20
-3:00 Arg -03/-02 1999 Oct 3
-4:00 Arg -04/-03 2000 Mar 3
-3:00 Arg -03/-02 2008 Oct 18
-3:00 - -03
#
# Tucumán (TM)
Zone America/Argentina/Tucuman -4:20:52 - LMT 1894 Oct 31
-4:16:48 - CMT 1920 May
-4:00 - -04 1930 Dec
-4:00 Arg -04/-03 1969 Oct 5
-3:00 Arg -03/-02 1991 Mar 3
-4:00 - -04 1991 Oct 20
-3:00 Arg -03/-02 1999 Oct 3
-4:00 Arg -04/-03 2000 Mar 3
-3:00 - -03 2004 Jun 1
-4:00 - -04 2004 Jun 13
-3:00 Arg -03/-02
#
# La Rioja (LR)
Zone America/Argentina/La_Rioja -4:27:24 - LMT 1894 Oct 31
-4:16:48 - CMT 1920 May
-4:00 - -04 1930 Dec
-4:00 Arg -04/-03 1969 Oct 5
-3:00 Arg -03/-02 1991 Mar 1
-4:00 - -04 1991 May 7
-3:00 Arg -03/-02 1999 Oct 3
-4:00 Arg -04/-03 2000 Mar 3
-3:00 - -03 2004 Jun 1
-4:00 - -04 2004 Jun 20
-3:00 Arg -03/-02 2008 Oct 18
-3:00 - -03
#
# San Juan (SJ)
Zone America/Argentina/San_Juan -4:34:04 - LMT 1894 Oct 31
-4:16:48 - CMT 1920 May
-4:00 - -04 1930 Dec
-4:00 Arg -04/-03 1969 Oct 5
-3:00 Arg -03/-02 1991 Mar 1
-4:00 - -04 1991 May 7
-3:00 Arg -03/-02 1999 Oct 3
-4:00 Arg -04/-03 2000 Mar 3
-3:00 - -03 2004 May 31
-4:00 - -04 2004 Jul 25
-3:00 Arg -03/-02 2008 Oct 18
-3:00 - -03
#
# Jujuy (JY)
Zone America/Argentina/Jujuy -4:21:12 - LMT 1894 Oct 31
-4:16:48 - CMT 1920 May
-4:00 - -04 1930 Dec
-4:00 Arg -04/-03 1969 Oct 5
-3:00 Arg -03/-02 1990 Mar 4
-4:00 - -04 1990 Oct 28
-4:00 1:00 -03 1991 Mar 17
-4:00 - -04 1991 Oct 6
-3:00 1:00 -02 1992
-3:00 Arg -03/-02 1999 Oct 3
-4:00 Arg -04/-03 2000 Mar 3
-3:00 Arg -03/-02 2008 Oct 18
-3:00 - -03
#
# Catamarca (CT), Chubut (CH)
Zone America/Argentina/Catamarca -4:23:08 - LMT 1894 Oct 31
-4:16:48 - CMT 1920 May
-4:00 - -04 1930 Dec
-4:00 Arg -04/-03 1969 Oct 5
-3:00 Arg -03/-02 1991 Mar 3
-4:00 - -04 1991 Oct 20
-3:00 Arg -03/-02 1999 Oct 3
-4:00 Arg -04/-03 2000 Mar 3
-3:00 - -03 2004 Jun 1
-4:00 - -04 2004 Jun 20
-3:00 Arg -03/-02 2008 Oct 18
-3:00 - -03
#
# Mendoza (MZ)
Zone America/Argentina/Mendoza -4:35:16 - LMT 1894 Oct 31
-4:16:48 - CMT 1920 May
-4:00 - -04 1930 Dec
-4:00 Arg -04/-03 1969 Oct 5
-3:00 Arg -03/-02 1990 Mar 4
-4:00 - -04 1990 Oct 15
-4:00 1:00 -03 1991 Mar 1
-4:00 - -04 1991 Oct 15
-4:00 1:00 -03 1992 Mar 1
-4:00 - -04 1992 Oct 18
-3:00 Arg -03/-02 1999 Oct 3
-4:00 Arg -04/-03 2000 Mar 3
-3:00 - -03 2004 May 23
-4:00 - -04 2004 Sep 26
-3:00 Arg -03/-02 2008 Oct 18
-3:00 - -03
#
# San Luis (SL)
Rule SanLuis 2008 2009 - Mar Sun>=8 0:00 0 -
Rule SanLuis 2007 2008 - Oct Sun>=8 0:00 1:00 -
Zone America/Argentina/San_Luis -4:25:24 - LMT 1894 Oct 31
-4:16:48 - CMT 1920 May
-4:00 - -04 1930 Dec
-4:00 Arg -04/-03 1969 Oct 5
-3:00 Arg -03/-02 1990
-3:00 1:00 -02 1990 Mar 14
-4:00 - -04 1990 Oct 15
-4:00 1:00 -03 1991 Mar 1
-4:00 - -04 1991 Jun 1
-3:00 - -03 1999 Oct 3
-4:00 1:00 -03 2000 Mar 3
-3:00 - -03 2004 May 31
-4:00 - -04 2004 Jul 25
-3:00 Arg -03/-02 2008 Jan 21
-4:00 SanLuis -04/-03 2009 Oct 11
-3:00 - -03
#
# Santa Cruz (SC)
Zone America/Argentina/Rio_Gallegos -4:36:52 - LMT 1894 Oct 31
-4:16:48 - CMT 1920 May
-4:00 - -04 1930 Dec
-4:00 Arg -04/-03 1969 Oct 5
-3:00 Arg -03/-02 1999 Oct 3
-4:00 Arg -04/-03 2000 Mar 3
-3:00 - -03 2004 Jun 1
-4:00 - -04 2004 Jun 20
-3:00 Arg -03/-02 2008 Oct 18
-3:00 - -03
#
# Tierra del Fuego, Antártida e Islas del Atlántico Sur (TF)
Zone America/Argentina/Ushuaia -4:33:12 - LMT 1894 Oct 31
-4:16:48 - CMT 1920 May
-4:00 - -04 1930 Dec
-4:00 Arg -04/-03 1969 Oct 5
-3:00 Arg -03/-02 1999 Oct 3
-4:00 Arg -04/-03 2000 Mar 3
-3:00 - -03 2004 May 30
-4:00 - -04 2004 Jun 20
-3:00 Arg -03/-02 2008 Oct 18
-3:00 - -03
# Aruba
Link America/Curacao America/Aruba
# Bolivia
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/La_Paz -4:32:36 - LMT 1890
-4:32:36 - CMT 1931 Oct 15 # Calamarca MT
-4:32:36 1:00 BST 1932 Mar 21 # Bolivia ST
-4:00 - -04
# Brazil
# From Paul Eggert (1993-11-18):
# The mayor of Rio recently attempted to change the time zone rules
# just in his city, in order to leave more summer time for the tourist trade.
# The rule change lasted only part of the day;
# the federal government refused to follow the city's rules, and business
# was in a chaos, so the mayor backed down that afternoon.
# From IATA SSIM (1996-02):
# _Only_ the following states in BR1 observe DST: Rio Grande do Sul (RS),
# Santa Catarina (SC), Paraná (PR), São Paulo (SP), Rio de Janeiro (RJ),
# Espírito Santo (ES), Minas Gerais (MG), Bahia (BA), Goiás (GO),
# Distrito Federal (DF), Tocantins (TO), Sergipe [SE] and Alagoas [AL].
# [The last three states are new to this issue of the IATA SSIM.]
# From Gwillim Law (1996-10-07):
# Geography, history (Tocantins was part of Goiás until 1989), and other
# sources of time zone information lead me to believe that AL, SE, and TO were
# always in BR1, and so the only change was whether or not they observed DST....
# The earliest issue of the SSIM I have is 2/91. Each issue from then until
# 9/95 says that DST is observed only in the ten states I quoted from 9/95,
# along with Mato Grosso (MT) and Mato Grosso do Sul (MS), which are in BR2
# (UTC-4).... The other two time zones given for Brazil are BR3, which is
# UTC-5, no DST, and applies only in the state of Acre (AC); and BR4, which is
# UTC-2, and applies to Fernando de Noronha (formerly FN, but I believe it's
# become part of the state of Pernambuco). The boundary between BR1 and BR2
# has never been clearly stated. They've simply been called East and West.
# However, some conclusions can be drawn from another IATA manual: the Airline
# Coding Directory, which lists close to 400 airports in Brazil. For each
# airport it gives a time zone which is coded to the SSIM. From that
# information, I'm led to conclude that the states of Amapá (AP), Ceará (CE),
# Maranhão (MA), Paraíba (PR), Pernambuco (PE), Piauí (PI), and Rio Grande do
# Norte (RN), and the eastern part of Pará (PA) are all in BR1 without DST.
# From Marcos Tadeu (1998-09-27):
# Brazilian official page <http://pcdsh01.on.br/verao1.html>
# From Jesper Nørgaard (2000-11-03):
# [For an official list of which regions in Brazil use which time zones, see:]
# http://pcdsh01.on.br/Fusbr.htm
# http://pcdsh01.on.br/Fusbrhv.htm
# From Celso Doria via David Madeo (2002-10-09):
# The reason for the delay this year has to do with elections in Brazil.
#
# Unlike in the United States, elections in Brazil are 100% computerized and
# the results are known almost immediately. Yesterday, it was the first
# round of the elections when 115 million Brazilians voted for President,
# Governor, Senators, Federal Deputies, and State Deputies. Nobody is
# counting (or re-counting) votes anymore and we know there will be a second
# round for the Presidency and also for some Governors. The 2nd round will
# take place on October 27th.
#
# The reason why the DST will only begin November 3rd is that the thousands
# of electoral machines used cannot have their time changed, and since the
# Constitution says the elections must begin at 8:00 AM and end at 5:00 PM,
# the Government decided to postpone DST, instead of changing the Constitution
# (maybe, for the next elections, it will be possible to change the clock)...
# From Rodrigo Severo (2004-10-04):
# It's just the biannual change made necessary by the much hyped, supposedly
# modern Brazilian eletronic voting machines which, apparently, can't deal
# with a time change between the first and the second rounds of the elections.
# From Steffen Thorsen (2007-09-20):
# Brazil will start DST on 2007-10-14 00:00 and end on 2008-02-17 00:00:
# http://www.mme.gov.br/site/news/detail.do;jsessionid=BBA06811AFCAAC28F0285210913513DA?newsId=13975
# From Paul Schulze (2008-06-24):
# ...by law number 11.662 of April 24, 2008 (published in the "Diario
# Oficial da União"...) in Brazil there are changes in the timezones,
# effective today (00:00am at June 24, 2008) as follows:
#
# a) The timezone UTC+5 is extinguished, with all the Acre state and the
# part of the Amazonas state that had this timezone now being put to the
# timezone UTC+4
# b) The whole Pará state now is put at timezone UTC+3, instead of just
# part of it, as was before.
#
# This change follows a proposal of senator Tiao Viana of Acre state, that
# proposed it due to concerns about open television channels displaying
# programs inappropriate to youths in the states that had the timezone
# UTC+5 too early in the night. In the occasion, some more corrections
# were proposed, trying to unify the timezones of any given state. This
# change modifies timezone rules defined in decree 2.784 of 18 June,
# 1913.
# From Rodrigo Severo (2008-06-24):
# Just correcting the URL:
# https://www.in.gov.br/imprensa/visualiza/index.jsp?jornal=do&secao=1&pagina=1&data=25/04/2008
#
# As a result of the above Decree I believe the America/Rio_Branco
# timezone shall be modified from UTC-5 to UTC-4 and a new timezone shall
# be created to represent the...west side of the Pará State. I
# suggest this new timezone be called Santarem as the most
# important/populated city in the affected area.
#
# This new timezone would be the same as the Rio_Branco timezone up to
# the 2008/06/24 change which would be to UTC-3 instead of UTC-4.
# From Alex Krivenyshev (2008-06-24):
# This is a quick reference page for New and Old Brazil Time Zones map.
# http://www.worldtimezone.com/brazil-time-new-old.php
#
# - 4 time zones replaced by 3 time zones - eliminating time zone UTC-05
# (state Acre and the part of the Amazonas will be UTC/GMT-04) - western
# part of Par state is moving to one timezone UTC-03 (from UTC-04).
# From Paul Eggert (2002-10-10):
# The official decrees referenced below are mostly taken from
# Decretos sobre o Horário de Verão no Brasil.
# http://pcdsh01.on.br/DecHV.html
# From Steffen Thorsen (2008-08-29):
# As announced by the government and many newspapers in Brazil late
# yesterday, Brazil will start DST on 2008-10-19 (need to change rule) and
# it will end on 2009-02-15 (current rule for Brazil is fine). Based on
# past years experience with the elections, there was a good chance that
# the start was postponed to November, but it did not happen this year.
#
# It has not yet been posted to http://pcdsh01.on.br/DecHV.html
#
# An official page about it:
# http://www.mme.gov.br/site/news/detail.do?newsId=16722
# Note that this link does not always work directly, but must be accessed
# by going to
# http://www.mme.gov.br/first
#
# One example link that works directly:
# http://jornale.com.br/index.php?option=com_content&task=view&id=13530&Itemid=54
# (Portuguese)
#
# We have a written a short article about it as well:
# https://www.timeanddate.com/news/time/brazil-dst-2008-2009.html
#
# From Alexander Krivenyshev (2011-10-04):
# State Bahia will return to Daylight savings time this year after 8 years off.
# The announcement was made by Governor Jaques Wagner in an interview to a
# television station in Salvador.
# In Portuguese:
# http://g1.globo.com/bahia/noticia/2011/10/governador-jaques-wagner-confirma-horario-de-verao-na-bahia.html
# https://noticias.terra.com.br/brasil/noticias/0,,OI5390887-EI8139,00-Bahia+volta+a+ter+horario+de+verao+apos+oito+anos.html
# From Guilherme Bernardes Rodrigues (2011-10-07):
# There is news in the media, however there is still no decree about it.
# I just send a e-mail to Zulmira Brandao at http://pcdsh01.on.br/ the
# official agency about time in Brazil, and she confirmed that the old rule is
# still in force.
# From Guilherme Bernardes Rodrigues (2011-10-14)
# It's official, the President signed a decree that includes Bahia in summer
# time.
# [ and in a second message (same day): ]
# I found the decree.
#
# DECRETO No. 7.584, DE 13 DE OUTUBRO DE 2011
# Link :
# http://www.in.gov.br/visualiza/index.jsp?data=13/10/2011&jornal=1000&pagina=6&totalArquivos=6
# From Kelley Cook (2012-10-16):
# The governor of state of Bahia in Brazil announced on Thursday that
# due to public pressure, he is reversing the DST policy they implemented
# last year and will not be going to Summer Time on October 21st....
# http://www.correio24horas.com.br/r/artigo/apos-pressoes-wagner-suspende-horario-de-verao-na-bahia
# From Rodrigo Severo (2012-10-16):
# Tocantins state will have DST.
# https://noticias.terra.com.br/brasil/noticias/0,,OI6232536-EI306.html
# From Steffen Thorsen (2013-09-20):
# Tocantins in Brazil is very likely not to observe DST from October....
# http://conexaoto.com.br/2013/09/18/ministerio-confirma-que-tocantins-esta-fora-do-horario-de-verao-em-2013-mas-falta-publicacao-de-decreto
# We will keep this article updated when this is confirmed:
# https://www.timeanddate.com/news/time/brazil-starts-dst-2013.html
# From Steffen Thorsen (2013-10-17):
# https://www.timeanddate.com/news/time/acre-amazonas-change-time-zone.html
# Senator Jorge Viana announced that Acre will change time zone on November 10.
# He did not specify the time of the change, nor if western parts of Amazonas
# will change as well.
#
# From Paul Eggert (2013-10-17):
# For now, assume western Amazonas will change as well.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
# Decree 20,466 <http://pcdsh01.on.br/HV20466.htm> (1931-10-01)
# Decree 21,896 <http://pcdsh01.on.br/HV21896.htm> (1932-01-10)
Rule Brazil 1931 only - Oct 3 11:00 1:00 -
Rule Brazil 1932 1933 - Apr 1 0:00 0 -
Rule Brazil 1932 only - Oct 3 0:00 1:00 -
# Decree 23,195 <http://pcdsh01.on.br/HV23195.htm> (1933-10-10)
# revoked DST.
# Decree 27,496 <http://pcdsh01.on.br/HV27496.htm> (1949-11-24)
# Decree 27,998 <http://pcdsh01.on.br/HV27998.htm> (1950-04-13)
Rule Brazil 1949 1952 - Dec 1 0:00 1:00 -
Rule Brazil 1950 only - Apr 16 1:00 0 -
Rule Brazil 1951 1952 - Apr 1 0:00 0 -
# Decree 32,308 <http://pcdsh01.on.br/HV32308.htm> (1953-02-24)
Rule Brazil 1953 only - Mar 1 0:00 0 -
# Decree 34,724 <http://pcdsh01.on.br/HV34724.htm> (1953-11-30)
# revoked DST.
# Decree 52,700 <http://pcdsh01.on.br/HV52700.htm> (1963-10-18)
# established DST from 1963-10-23 00:00 to 1964-02-29 00:00
# in SP, RJ, GB, MG, ES, due to the prolongation of the drought.
# Decree 53,071 <http://pcdsh01.on.br/HV53071.htm> (1963-12-03)
# extended the above decree to all of the national territory on 12-09.
Rule Brazil 1963 only - Dec 9 0:00 1:00 -
# Decree 53,604 <http://pcdsh01.on.br/HV53604.htm> (1964-02-25)
# extended summer time by one day to 1964-03-01 00:00 (start of school).
Rule Brazil 1964 only - Mar 1 0:00 0 -
# Decree 55,639 <http://pcdsh01.on.br/HV55639.htm> (1965-01-27)
Rule Brazil 1965 only - Jan 31 0:00 1:00 -
Rule Brazil 1965 only - Mar 31 0:00 0 -
# Decree 57,303 <http://pcdsh01.on.br/HV57303.htm> (1965-11-22)
Rule Brazil 1965 only - Dec 1 0:00 1:00 -
# Decree 57,843 <http://pcdsh01.on.br/HV57843.htm> (1966-02-18)
Rule Brazil 1966 1968 - Mar 1 0:00 0 -
Rule Brazil 1966 1967 - Nov 1 0:00 1:00 -
# Decree 63,429 <http://pcdsh01.on.br/HV63429.htm> (1968-10-15)
# revoked DST.
# Decree 91,698 <http://pcdsh01.on.br/HV91698.htm> (1985-09-27)
Rule Brazil 1985 only - Nov 2 0:00 1:00 -
# Decree 92,310 (1986-01-21)
# Decree 92,463 (1986-03-13)
Rule Brazil 1986 only - Mar 15 0:00 0 -
# Decree 93,316 (1986-10-01)
Rule Brazil 1986 only - Oct 25 0:00 1:00 -
Rule Brazil 1987 only - Feb 14 0:00 0 -
# Decree 94,922 <http://pcdsh01.on.br/HV94922.htm> (1987-09-22)
Rule Brazil 1987 only - Oct 25 0:00 1:00 -
Rule Brazil 1988 only - Feb 7 0:00 0 -
# Decree 96,676 <http://pcdsh01.on.br/HV96676.htm> (1988-09-12)
# except for the states of AC, AM, PA, RR, RO, and AP (then a territory)
Rule Brazil 1988 only - Oct 16 0:00 1:00 -
Rule Brazil 1989 only - Jan 29 0:00 0 -
# Decree 98,077 <http://pcdsh01.on.br/HV98077.htm> (1989-08-21)
# with the same exceptions
Rule Brazil 1989 only - Oct 15 0:00 1:00 -
Rule Brazil 1990 only - Feb 11 0:00 0 -
# Decree 99,530 <http://pcdsh01.on.br/HV99530.htm> (1990-09-17)
# adopted by RS, SC, PR, SP, RJ, ES, MG, GO, MS, DF.
# Decree 99,629 (1990-10-19) adds BA, MT.
Rule Brazil 1990 only - Oct 21 0:00 1:00 -
Rule Brazil 1991 only - Feb 17 0:00 0 -
# Unnumbered decree <http://pcdsh01.on.br/HV1991.htm> (1991-09-25)
# adopted by RS, SC, PR, SP, RJ, ES, MG, BA, GO, MT, MS, DF.
Rule Brazil 1991 only - Oct 20 0:00 1:00 -
Rule Brazil 1992 only - Feb 9 0:00 0 -
# Unnumbered decree <http://pcdsh01.on.br/HV1992.htm> (1992-10-16)
# adopted by same states.
Rule Brazil 1992 only - Oct 25 0:00 1:00 -
Rule Brazil 1993 only - Jan 31 0:00 0 -
# Decree 942 <http://pcdsh01.on.br/HV942.htm> (1993-09-28)
# adopted by same states, plus AM.
# Decree 1,252 <http://pcdsh01.on.br/HV1252.htm> (1994-09-22;
# web page corrected 2004-01-07) adopted by same states, minus AM.
# Decree 1,636 <http://pcdsh01.on.br/HV1636.htm> (1995-09-14)
# adopted by same states, plus MT and TO.
# Decree 1,674 <http://pcdsh01.on.br/HV1674.htm> (1995-10-13)
# adds AL, SE.
Rule Brazil 1993 1995 - Oct Sun>=11 0:00 1:00 -
Rule Brazil 1994 1995 - Feb Sun>=15 0:00 0 -
Rule Brazil 1996 only - Feb 11 0:00 0 -
# Decree 2,000 <http://pcdsh01.on.br/HV2000.htm> (1996-09-04)
# adopted by same states, minus AL, SE.
Rule Brazil 1996 only - Oct 6 0:00 1:00 -
Rule Brazil 1997 only - Feb 16 0:00 0 -
# From Daniel C. Sobral (1998-02-12):
# In 1997, the DS began on October 6. The stated reason was that
# because international television networks ignored Brazil's policy on DS,
# they bought the wrong times on satellite for coverage of Pope's visit.
# This year, the ending date of DS was postponed to March 1
# to help dealing with the shortages of electric power.
#
# Decree 2,317 (1997-09-04), adopted by same states.
Rule Brazil 1997 only - Oct 6 0:00 1:00 -
# Decree 2,495 <http://pcdsh01.on.br/figuras/HV2495.JPG>
# (1998-02-10)
Rule Brazil 1998 only - Mar 1 0:00 0 -
# Decree 2,780 <http://pcdsh01.on.br/figuras/Hv98.jpg> (1998-09-11)
# adopted by the same states as before.
Rule Brazil 1998 only - Oct 11 0:00 1:00 -
Rule Brazil 1999 only - Feb 21 0:00 0 -
# Decree 3,150 <http://pcdsh01.on.br/figuras/HV3150.gif>
# (1999-08-23) adopted by same states.
# Decree 3,188 <http://pcdsh01.on.br/DecHV99.gif> (1999-09-30)
# adds SE, AL, PB, PE, RN, CE, PI, MA and RR.
Rule Brazil 1999 only - Oct 3 0:00 1:00 -
Rule Brazil 2000 only - Feb 27 0:00 0 -
# Decree 3,592 <http://pcdsh01.on.br/DEC3592.htm> (2000-09-06)
# adopted by the same states as before.
# Decree 3,630 <http://pcdsh01.on.br/Dec3630.jpg> (2000-10-13)
# repeals DST in PE and RR, effective 2000-10-15 00:00.
# Decree 3,632 <http://pcdsh01.on.br/Dec3632.jpg> (2000-10-17)
# repeals DST in SE, AL, PB, RN, CE, PI and MA, effective 2000-10-22 00:00.
# Decree 3,916 <http://pcdsh01.on.br/figuras/HV3916.gif>
# (2001-09-13) reestablishes DST in AL, CE, MA, PB, PE, PI, RN, SE.
Rule Brazil 2000 2001 - Oct Sun>=8 0:00 1:00 -
Rule Brazil 2001 2006 - Feb Sun>=15 0:00 0 -
# Decree 4,399 (2002-10-01) repeals DST in AL, CE, MA, PB, PE, PI, RN, SE.
# 4,399 <http://www.presidencia.gov.br/CCIVIL/decreto/2002/D4399.htm>
Rule Brazil 2002 only - Nov 3 0:00 1:00 -
# Decree 4,844 (2003-09-24; corrected 2003-09-26) repeals DST in BA, MT, TO.
# 4,844 <http://www.presidencia.gov.br/CCIVIL/decreto/2003/D4844.htm>
Rule Brazil 2003 only - Oct 19 0:00 1:00 -
# Decree 5,223 (2004-10-01) reestablishes DST in MT.
# 5,223 <http://www.planalto.gov.br/ccivil_03/_Ato2004-2006/2004/Decreto/D5223.htm>
Rule Brazil 2004 only - Nov 2 0:00 1:00 -
# Decree 5,539 <http://pcdsh01.on.br/DecHV5539.gif> (2005-09-19),
# adopted by the same states as before.
Rule Brazil 2005 only - Oct 16 0:00 1:00 -
# Decree 5,920 <http://pcdsh01.on.br/DecHV5920.gif> (2006-10-03),
# adopted by the same states as before.
Rule Brazil 2006 only - Nov 5 0:00 1:00 -
Rule Brazil 2007 only - Feb 25 0:00 0 -
# Decree 6,212 <http://pcdsh01.on.br/DecHV6212.gif> (2007-09-26),
# adopted by the same states as before.
Rule Brazil 2007 only - Oct Sun>=8 0:00 1:00 -
# From Frederico A. C. Neves (2008-09-10):
# According to this decree
# http://www.planalto.gov.br/ccivil_03/_Ato2007-2010/2008/Decreto/D6558.htm
# [t]he DST period in Brazil now on will be from the 3rd Oct Sunday to the
# 3rd Feb Sunday. There is an exception on the return date when this is
# the Carnival Sunday then the return date will be the next Sunday...
Rule Brazil 2008 2017 - Oct Sun>=15 0:00 1:00 -
Rule Brazil 2008 2011 - Feb Sun>=15 0:00 0 -
# Decree 7,584 <http://pcdsh01.on.br/HVdecreto7584_20111013.jpg> (2011-10-13)
# added Bahia.
Rule Brazil 2012 only - Feb Sun>=22 0:00 0 -
# Decree 7,826 <http://pcdsh01.on.br/HVdecreto7826_20121015.jpg> (2012-10-15)
# removed Bahia and added Tocantins.
# Decree 8,112 <http://pcdsh01.on.br/HVdecreto8112_20130930.JPG> (2013-09-30)
# removed Tocantins.
Rule Brazil 2013 2014 - Feb Sun>=15 0:00 0 -
Rule Brazil 2015 only - Feb Sun>=22 0:00 0 -
Rule Brazil 2016 2019 - Feb Sun>=15 0:00 0 -
# From Steffen Thorsen (2017-12-18):
# According to many media sources, next year's DST start in Brazil will move to
# the first Sunday of November
# ... https://www.timeanddate.com/news/time/brazil-delays-dst-2018.html
# From Steffen Thorsen (2017-12-20):
# http://www.planalto.gov.br/ccivil_03/_ato2015-2018/2017/decreto/D9242.htm
# From Fábio Gomes (2018-10-04):
# The Brazilian president just announced a new change on this year DST.
# It was scheduled to start on November 4th and it was changed to November 18th.
# From Rodrigo Brüning Wessler (2018-10-15):
# The Brazilian government just announced that the change in DST was
# canceled.... Maybe the president Michel Temer also woke up one hour
# earlier today. :)
Rule Brazil 2018 only - Nov Sun>=1 0:00 1:00 -
# The last ruleset listed above says that the following states observed DST:
# DF, ES, GO, MG, MS, MT, PR, RJ, RS, SC, SP.
#
# From Steffen Thorsen (2019-04-05):
# According to multiple sources the Brazilian president wants to get rid of DST.
# https://gmconline.com.br/noticias/politica/bolsonaro-horario-de-verao-deve-acabar-este-ano
# https://g1.globo.com/economia/noticia/2019/04/05/governo-anuncia-fim-do-horario-de-verao.ghtml
# From Marcus Diniz (2019-04-25):
# Brazil no longer has DST changes - decree signed today
# https://g1.globo.com/politica/noticia/2019/04/25/bolsonaro-assina-decreto-que-acaba-com-o-horario-de-verao.ghtml
# From Daniel Soares de Oliveira (2019-04-26):
# http://www.planalto.gov.br/ccivil_03/_Ato2019-2022/2019/Decreto/D9772.htm
# Zone NAME STDOFF RULES FORMAT [UNTIL]
#
# Fernando de Noronha (administratively part of PE)
Zone America/Noronha -2:09:40 - LMT 1914
-2:00 Brazil -02/-01 1990 Sep 17
-2:00 - -02 1999 Sep 30
-2:00 Brazil -02/-01 2000 Oct 15
-2:00 - -02 2001 Sep 13
-2:00 Brazil -02/-01 2002 Oct 1
-2:00 - -02
# Other Atlantic islands have no permanent settlement.
# These include Trindade and Martim Vaz (administratively part of ES),
# Rocas Atoll (RN), and the St Peter and St Paul Archipelago (PE).
# Fernando de Noronha was a separate territory from 1942-09-02 to 1989-01-01;
# it also included the Penedos.
#
# Amapá (AP), east Pará (PA)
# East Pará includes Belém, Marabá, Serra Norte, and São Félix do Xingu.
# The division between east and west Pará is the river Xingu.
# In the north a very small part from the river Javary (now Jari I guess,
# the border with Amapá) to the Amazon, then to the Xingu.
Zone America/Belem -3:13:56 - LMT 1914
-3:00 Brazil -03/-02 1988 Sep 12
-3:00 - -03
#
# west Pará (PA)
# West Pará includes Altamira, Óbidos, Prainha, Oriximiná, and Santarém.
Zone America/Santarem -3:38:48 - LMT 1914
-4:00 Brazil -04/-03 1988 Sep 12
-4:00 - -04 2008 Jun 24 0:00
-3:00 - -03
#
# Maranhão (MA), Piauí (PI), Ceará (CE), Rio Grande do Norte (RN),
# Paraíba (PB)
Zone America/Fortaleza -2:34:00 - LMT 1914
-3:00 Brazil -03/-02 1990 Sep 17
-3:00 - -03 1999 Sep 30
-3:00 Brazil -03/-02 2000 Oct 22
-3:00 - -03 2001 Sep 13
-3:00 Brazil -03/-02 2002 Oct 1
-3:00 - -03
#
# Pernambuco (PE) (except Atlantic islands)
Zone America/Recife -2:19:36 - LMT 1914
-3:00 Brazil -03/-02 1990 Sep 17
-3:00 - -03 1999 Sep 30
-3:00 Brazil -03/-02 2000 Oct 15
-3:00 - -03 2001 Sep 13
-3:00 Brazil -03/-02 2002 Oct 1
-3:00 - -03
#
# Tocantins (TO)
Zone America/Araguaina -3:12:48 - LMT 1914
-3:00 Brazil -03/-02 1990 Sep 17
-3:00 - -03 1995 Sep 14
-3:00 Brazil -03/-02 2003 Sep 24
-3:00 - -03 2012 Oct 21
-3:00 Brazil -03/-02 2013 Sep
-3:00 - -03
#
# Alagoas (AL), Sergipe (SE)
Zone America/Maceio -2:22:52 - LMT 1914
-3:00 Brazil -03/-02 1990 Sep 17
-3:00 - -03 1995 Oct 13
-3:00 Brazil -03/-02 1996 Sep 4
-3:00 - -03 1999 Sep 30
-3:00 Brazil -03/-02 2000 Oct 22
-3:00 - -03 2001 Sep 13
-3:00 Brazil -03/-02 2002 Oct 1
-3:00 - -03
#
# Bahia (BA)
# There are too many Salvadors elsewhere, so use America/Bahia instead
# of America/Salvador.
Zone America/Bahia -2:34:04 - LMT 1914
-3:00 Brazil -03/-02 2003 Sep 24
-3:00 - -03 2011 Oct 16
-3:00 Brazil -03/-02 2012 Oct 21
-3:00 - -03
#
# Goiás (GO), Distrito Federal (DF), Minas Gerais (MG),
# Espírito Santo (ES), Rio de Janeiro (RJ), São Paulo (SP), Paraná (PR),
# Santa Catarina (SC), Rio Grande do Sul (RS)
Zone America/Sao_Paulo -3:06:28 - LMT 1914
-3:00 Brazil -03/-02 1963 Oct 23 0:00
-3:00 1:00 -02 1964
-3:00 Brazil -03/-02
#
# Mato Grosso do Sul (MS)
Zone America/Campo_Grande -3:38:28 - LMT 1914
-4:00 Brazil -04/-03
#
# Mato Grosso (MT)
Zone America/Cuiaba -3:44:20 - LMT 1914
-4:00 Brazil -04/-03 2003 Sep 24
-4:00 - -04 2004 Oct 1
-4:00 Brazil -04/-03
#
# Rondônia (RO)
Zone America/Porto_Velho -4:15:36 - LMT 1914
-4:00 Brazil -04/-03 1988 Sep 12
-4:00 - -04
#
# Roraima (RR)
Zone America/Boa_Vista -4:02:40 - LMT 1914
-4:00 Brazil -04/-03 1988 Sep 12
-4:00 - -04 1999 Sep 30
-4:00 Brazil -04/-03 2000 Oct 15
-4:00 - -04
#
# east Amazonas (AM): Boca do Acre, Jutaí, Manaus, Floriano Peixoto
# The great circle line from Tabatinga to Porto Acre divides
# east from west Amazonas.
Zone America/Manaus -4:00:04 - LMT 1914
-4:00 Brazil -04/-03 1988 Sep 12
-4:00 - -04 1993 Sep 28
-4:00 Brazil -04/-03 1994 Sep 22
-4:00 - -04
#
# west Amazonas (AM): Atalaia do Norte, Boca do Maoco, Benjamin Constant,
# Eirunepé, Envira, Ipixuna
Zone America/Eirunepe -4:39:28 - LMT 1914
-5:00 Brazil -05/-04 1988 Sep 12
-5:00 - -05 1993 Sep 28
-5:00 Brazil -05/-04 1994 Sep 22
-5:00 - -05 2008 Jun 24 0:00
-4:00 - -04 2013 Nov 10
-5:00 - -05
#
# Acre (AC)
Zone America/Rio_Branco -4:31:12 - LMT 1914
-5:00 Brazil -05/-04 1988 Sep 12
-5:00 - -05 2008 Jun 24 0:00
-4:00 - -04 2013 Nov 10
-5:00 - -05
# Chile
# From Paul Eggert (2015-04-03):
# Shanks & Pottenger says America/Santiago introduced standard time in
# 1890 and rounds its UT offset to 70W40; guess that in practice this
# was the same offset as in 1916-1919. It also says Pacific/Easter
# standardized on 109W22 in 1890; assume this didn't change the clocks.
#
# Dates for America/Santiago from 1910 to 2004 are primarily from
# the following source, cited by Oscar van Vlijmen (2006-10-08):
# [1] Chile Law
# http://www.webexhibits.org/daylightsaving/chile.html
# This contains a copy of this official table:
# Cambios en la hora oficial de Chile desde 1900 (retrieved 2008-03-30)
# https://web.archive.org/web/20080330200901/http://www.horaoficial.cl/cambio.htm
# [1] needs several corrections, though.
#
# The first set of corrections is from:
# [2] History of the Official Time of Chile
# http://www.horaoficial.cl/ing/horaof_ing.html (retrieved 2012-03-06). See:
# https://web.archive.org/web/20120306042032/http://www.horaoficial.cl/ing/horaof_ing.html
# This is an English translation of:
# Historia de la hora oficial de Chile (retrieved 2012-10-24). See:
# https://web.archive.org/web/20121024234627/http://www.horaoficial.cl/horaof.htm
# A fancier Spanish version (requiring mouse-clicking) is at:
# http://www.horaoficial.cl/historia_hora.html
# Conflicts between [1] and [2] were resolved as follows:
#
# - [1] says the 1910 transition was Jan 1, [2] says Jan 10 and cites
# Boletín No. 1, Aviso No. 1 (1910). Go with [2].
#
# - [1] says SMT was -4:42:45, [2] says Chile's official time from
# 1916 to 1919 was -4:42:46.3, the meridian of Chile's National
# Astronomical Observatory (OAN), then located in what is now
# Quinta Normal in Santiago. Go with [2], rounding it to -4:42:46.
#
# - [1] says the 1918 transition was Sep 1, [2] says Sep 10 and cites
# Boletín No. 22, Aviso No. 129/1918 (1918-08-23). Go with [2].
#
# - [1] does not give times for transitions; assume they occur
# at midnight mainland time, the current common practice. However,
# go with [2]'s specification of 23:00 for the 1947-05-21 transition.
#
# Another correction to [1] is from Jesper Nørgaard Welen, who
# wrote (2006-10-08), "I think that there are some obvious mistakes in
# the suggested link from Oscar van Vlijmen,... for instance entry 66
# says that GMT-4 ended 1990-09-12 while entry 67 only begins GMT-3 at
# 1990-09-15 (they should have been 1990-09-15 and 1990-09-16
# respectively), but anyhow it clears up some doubts too."
#
# Data for Pacific/Easter from 1910 through 1967 come from Shanks &
# Pottenger. After that, for lack of better info assume
# Pacific/Easter is always two hours behind America/Santiago;
# this is known to work for DST transitions starting in 2008 and
# may well be true for earlier transitions.
# From Eduardo Krell (1995-10-19):
# The law says to switch to DST at midnight [24:00] on the second SATURDAY
# of October.... The law is the same for March and October.
# (1998-09-29):
# Because of the drought this year, the government decided to go into
# DST earlier (saturday 9/26 at 24:00). This is a one-time change only ...
# (unless there's another dry season next year, I guess).
# From Julio I. Pacheco Troncoso (1999-03-18):
# Because of the same drought, the government decided to end DST later,
# on April 3, (one-time change).
# From Germán Poo-Caamaño (2008-03-03):
# Due to drought, Chile extends Daylight Time in three weeks. This
# is one-time change (Saturday 3/29 at 24:00 for America/Santiago
# and Saturday 3/29 at 22:00 for Pacific/Easter)
# The Supreme Decree is located at
# http://www.shoa.cl/servicios/supremo316.pdf
#
# From José Miguel Garrido (2008-03-05):
# http://www.shoa.cl/noticias/2008/04hora/hora.htm
# From Angel Chiang (2010-03-04):
# Subject: DST in Chile exceptionally extended to 3 April due to earthquake
# http://www.gobiernodechile.cl/viewNoticia.aspx?idArticulo=30098
#
# From Arthur David Olson (2010-03-06):
# Angel Chiang's message confirmed by Julio Pacheco; Julio provided a patch.
# From Glenn Eychaner (2011-03-28):
# http://diario.elmercurio.com/2011/03/28/_portada/_portada/noticias/7565897A-CA86-49E6-9E03-660B21A4883E.htm?id=3D{7565897A-CA86-49E6-9E03-660B21A4883E}
# In English:
# Chile's clocks will go back an hour this year on the 7th of May instead
# of this Saturday. They will go forward again the 3rd Saturday in
# August, not in October as they have since 1968.
# From Mauricio Parada (2012-02-22), translated by Glenn Eychaner (2012-02-23):
# As stated in the website of the Chilean Energy Ministry
# http://www.minenergia.cl/ministerio/noticias/generales/gobierno-anuncia-fechas-de-cambio-de.html
# The Chilean Government has decided to postpone the entrance into winter time
# (to leave DST) from March 11 2012 to April 28th 2012....
# Quote from the website communication:
#
# 6. For the year 2012, the dates of entry into winter time will be as follows:
# a. Saturday April 28, 2012, clocks should go back 60 minutes; that is, at
# 23:59:59, instead of passing to 0:00, the time should be adjusted to be 23:00
# of the same day.
# b. Saturday, September 1, 2012, clocks should go forward 60 minutes; that is,
# at 23:59:59, instead of passing to 0:00, the time should be adjusted to be
# 01:00 on September 2.
# From Steffen Thorsen (2013-02-15):
# According to several news sources, Chile has extended DST this year,
# they will end DST later and start DST earlier than planned. They
# hope to save energy. The new end date is 2013-04-28 00:00 and new
# start date is 2013-09-08 00:00....
# http://www.gob.cl/informa/2013/02/15/gobierno-anuncia-fechas-de-cambio-de-hora-para-el-ano-2013.htm
# From José Miguel Garrido (2014-02-19):
# Today appeared in the Diario Oficial a decree amending the time change
# dates to 2014.
# DST End: last Saturday of April 2014 (Sun 27 Apr 2014 03:00 UTC)
# DST Start: first Saturday of September 2014 (Sun 07 Sep 2014 04:00 UTC)
# http://www.diariooficial.interior.gob.cl//media/2014/02/19/do-20140219.pdf
# From Eduardo Romero Urra (2015-03-03):
# Today has been published officially that Chile will use the DST time
# permanently until March 25 of 2017
# http://www.diariooficial.interior.gob.cl/media/2015/03/03/1-large.jpg
#
# From Paul Eggert (2015-03-03):
# For now, assume that the extension will persist indefinitely.
# From Juan Correa (2016-03-18):
# The decree regarding DST has been published in today's Official Gazette:
# http://www.diariooficial.interior.gob.cl/versiones-anteriores/do/20160318/
# http://www.leychile.cl/Navegar?idNorma=1088502
# It does consider the second Saturday of May and August as the dates
# for the transition; and it lists DST dates until 2019, but I think
# this scheme will stick.
#
# From Paul Eggert (2016-03-18):
# For now, assume the pattern holds for the indefinite future.
# The decree says transitions occur at 24:00; in practice this appears
# to mean 24:00 mainland time, not 24:00 local time, so that Easter
# Island is always two hours behind the mainland.
# From Juan Correa (2016-12-04):
# Magallanes region ... will keep DST (UTC -3) all year round....
# http://www.soychile.cl/Santiago/Sociedad/2016/12/04/433428/Bachelet-firmo-el-decreto-para-establecer-un-horario-unico-para-la-Region-de-Magallanes.aspx
-#
# From Deborah Goldsmith (2017-01-19):
# http://www.diariooficial.interior.gob.cl/publicaciones/2017/01/17/41660/01/1169626.pdf
-# From Paul Eggert (2017-01-19):
-# The above says the Magallanes change expires 2019-05-11 at 24:00,
-# so in theory, they will revert to -04/-03 after that, which means
-# they will switch from -03 to -04 one hour after Santiago does that day.
-# For now, assume that they will not revert.
# From Juan Correa (2018-08-13):
# As of moments ago, the Ministry of Energy in Chile has announced the new
# schema for DST. ... Announcement in video (in Spanish):
# https://twitter.com/MinEnergia/status/1029000399129374720
# From Yonathan Dossow (2018-08-13):
# The video says "first Saturday of September", we all know it means Sunday at
# midnight.
# From Tim Parenti (2018-08-13):
# Translating the captions on the video at 0:44-0:55, "We want to announce as
# Government that from 2019, Winter Time will be increased to 5 months, between
# the first Saturday of April and the first Saturday of September."
# At 2:08-2:20, "The Magallanes region will maintain its current time, as
# decided by the citizens during 2017, but our Government will promote a
# regional dialogue table to gather their opinion on this matter."
# https://twitter.com/MinEnergia/status/1029009354001973248
# "We will keep the new time policy unchanged for at least the next 4 years."
# So we extend the new rules on Saturdays at 24:00 mainland time indefinitely.
# From Juan Correa (2019-02-04):
# http://www.diariooficial.interior.gob.cl/publicaciones/2018/11/23/42212/01/1498738.pdf
+# From Paul Eggert (2019-09-01):
+# The above says the Magallanes exception expires 2022-04-02 at 24:00,
+# so in theory, they will revert to -04/-03 after that.
+# For now, assume that they will not revert,
+# since they have extended the expiration date once already.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Chile 1927 1931 - Sep 1 0:00 1:00 -
Rule Chile 1928 1932 - Apr 1 0:00 0 -
Rule Chile 1968 only - Nov 3 4:00u 1:00 -
Rule Chile 1969 only - Mar 30 3:00u 0 -
Rule Chile 1969 only - Nov 23 4:00u 1:00 -
Rule Chile 1970 only - Mar 29 3:00u 0 -
Rule Chile 1971 only - Mar 14 3:00u 0 -
Rule Chile 1970 1972 - Oct Sun>=9 4:00u 1:00 -
Rule Chile 1972 1986 - Mar Sun>=9 3:00u 0 -
Rule Chile 1973 only - Sep 30 4:00u 1:00 -
Rule Chile 1974 1987 - Oct Sun>=9 4:00u 1:00 -
Rule Chile 1987 only - Apr 12 3:00u 0 -
Rule Chile 1988 1990 - Mar Sun>=9 3:00u 0 -
Rule Chile 1988 1989 - Oct Sun>=9 4:00u 1:00 -
Rule Chile 1990 only - Sep 16 4:00u 1:00 -
Rule Chile 1991 1996 - Mar Sun>=9 3:00u 0 -
Rule Chile 1991 1997 - Oct Sun>=9 4:00u 1:00 -
Rule Chile 1997 only - Mar 30 3:00u 0 -
Rule Chile 1998 only - Mar Sun>=9 3:00u 0 -
Rule Chile 1998 only - Sep 27 4:00u 1:00 -
Rule Chile 1999 only - Apr 4 3:00u 0 -
Rule Chile 1999 2010 - Oct Sun>=9 4:00u 1:00 -
Rule Chile 2000 2007 - Mar Sun>=9 3:00u 0 -
# N.B.: the end of March 29 in Chile is March 30 in Universal time,
# which is used below in specifying the transition.
Rule Chile 2008 only - Mar 30 3:00u 0 -
Rule Chile 2009 only - Mar Sun>=9 3:00u 0 -
Rule Chile 2010 only - Apr Sun>=1 3:00u 0 -
Rule Chile 2011 only - May Sun>=2 3:00u 0 -
Rule Chile 2011 only - Aug Sun>=16 4:00u 1:00 -
Rule Chile 2012 2014 - Apr Sun>=23 3:00u 0 -
Rule Chile 2012 2014 - Sep Sun>=2 4:00u 1:00 -
Rule Chile 2016 2018 - May Sun>=9 3:00u 0 -
Rule Chile 2016 2018 - Aug Sun>=9 4:00u 1:00 -
Rule Chile 2019 max - Apr Sun>=2 3:00u 0 -
Rule Chile 2019 max - Sep Sun>=2 4:00u 1:00 -
# IATA SSIM anomalies: (1992-02) says 1992-03-14;
# (1996-09) says 1998-03-08. Ignore these.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Santiago -4:42:46 - LMT 1890
-4:42:46 - SMT 1910 Jan 10 # Santiago Mean Time
-5:00 - -05 1916 Jul 1
-4:42:46 - SMT 1918 Sep 10
-4:00 - -04 1919 Jul 1
-4:42:46 - SMT 1927 Sep 1
-5:00 Chile -05/-04 1932 Sep 1
-4:00 - -04 1942 Jun 1
-5:00 - -05 1942 Aug 1
-4:00 - -04 1946 Jul 15
-4:00 1:00 -03 1946 Sep 1 # central Chile
-4:00 - -04 1947 Apr 1
-5:00 - -05 1947 May 21 23:00
-4:00 Chile -04/-03
Zone America/Punta_Arenas -4:43:40 - LMT 1890
-4:42:46 - SMT 1910 Jan 10
-5:00 - -05 1916 Jul 1
-4:42:46 - SMT 1918 Sep 10
-4:00 - -04 1919 Jul 1
-4:42:46 - SMT 1927 Sep 1
-5:00 Chile -05/-04 1932 Sep 1
-4:00 - -04 1942 Jun 1
-5:00 - -05 1942 Aug 1
-4:00 - -04 1947 Apr 1
-5:00 - -05 1947 May 21 23:00
-4:00 Chile -04/-03 2016 Dec 4
-3:00 - -03
Zone Pacific/Easter -7:17:28 - LMT 1890
-7:17:28 - EMT 1932 Sep # Easter Mean Time
-7:00 Chile -07/-06 1982 Mar 14 3:00u # Easter Time
-6:00 Chile -06/-05
#
# Salas y Gómez Island is uninhabited.
# Other Chilean locations, including Juan Fernández Is, Desventuradas Is,
# and Antarctic bases, are like America/Santiago.
# Antarctic base using South American rules
# (See the file 'antarctica' for more.)
#
# Palmer, Anvers Island, since 1965 (moved 2 miles in 1968)
#
# From Ethan Dicks (1996-10-06):
# It keeps the same time as Punta Arenas, Chile, because, just like us
# and the South Pole, that's the other end of their supply line....
# I verified with someone who was there that since 1980,
# Palmer has followed Chile. Prior to that, before the Falklands War,
# Palmer used to be supplied from Argentina.
#
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Antarctica/Palmer 0 - -00 1965
-4:00 Arg -04/-03 1969 Oct 5
-3:00 Arg -03/-02 1982 May
-4:00 Chile -04/-03 2016 Dec 4
-3:00 - -03
# Colombia
# Milne gives 4:56:16.4 for Bogotá time in 1899; round to nearest. He writes,
# "A variation of fifteen minutes in the public clocks of Bogota is not rare."
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule CO 1992 only - May 3 0:00 1:00 -
Rule CO 1993 only - Apr 4 0:00 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Bogota -4:56:16 - LMT 1884 Mar 13
-4:56:16 - BMT 1914 Nov 23 # Bogotá Mean Time
-5:00 CO -05/-04
# Malpelo, Providencia, San Andres
# no information; probably like America/Bogota
# Curaçao
# Milne gives 4:35:46.9 for Curaçao mean time; round to nearest.
#
# From Paul Eggert (2006-03-22):
# Shanks & Pottenger say that The Bottom and Philipsburg have been at
# -4:00 since standard time was introduced on 1912-03-02; and that
# Kralendijk and Rincon used Kralendijk Mean Time (-4:33:08) from
# 1912-02-02 to 1965-01-01. The former is dubious, since S&P also say
# Saba Island has been like Curaçao.
# This all predates our 1970 cutoff, though.
#
# By July 2007 Curaçao and St Maarten are planned to become
# associated states within the Netherlands, much like Aruba;
# Bonaire, Saba and St Eustatius would become directly part of the
# Netherlands as Kingdom Islands. This won't affect their time zones
# though, as far as we know.
#
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Curacao -4:35:47 - LMT 1912 Feb 12 # Willemstad
-4:30 - -0430 1965
-4:00 - AST
# From Arthur David Olson (2011-06-15):
# use links for places with new iso3166 codes.
# The name "Lower Prince's Quarter" is both longer than fourteen characters
# and contains an apostrophe; use "Lower_Princes" below.
Link America/Curacao America/Lower_Princes # Sint Maarten
Link America/Curacao America/Kralendijk # Caribbean Netherlands
# Ecuador
#
# Milne says the Central and South American Telegraph Company used -5:24:15.
#
# From Alois Treindl (2016-12-15):
# https://www.elcomercio.com/actualidad/hora-sixto-1993.html
# ... Whether the law applied also to Galápagos, I do not know.
# From Paul Eggert (2016-12-15):
# https://www.elcomercio.com/afull/modificacion-husohorario-ecuador-presidentes-decreto.html
# This says President Sixto Durán Ballén signed decree No. 285, which
# established DST from 1992-11-28 to 1993-02-05; it does not give transition
# times. The people called it "hora de Sixto" ("Sixto hour"). The change did
# not go over well; a popular song "Qué hora es" by Jaime Guevara had lyrics
# that included "Amanecía en mitad de la noche, los guaguas iban a clase sin
# sol" ("It was dawning in the middle of the night, the buses went to class
# without sun"). Although Ballén's campaign slogan was "Ni un paso atrás"
# (Not one step back), the clocks went back in 1993 and the experiment was not
# repeated. For now, assume transitions were at 00:00 local time country-wide.
#
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Ecuador 1992 only - Nov 28 0:00 1:00 -
Rule Ecuador 1993 only - Feb 5 0:00 0 -
#
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Guayaquil -5:19:20 - LMT 1890
-5:14:00 - QMT 1931 # Quito Mean Time
-5:00 Ecuador -05/-04
Zone Pacific/Galapagos -5:58:24 - LMT 1931 # Puerto Baquerizo Moreno
-5:00 - -05 1986
-6:00 Ecuador -06/-05
# Falklands
# From Paul Eggert (2006-03-22):
# Between 1990 and 2000 inclusive, Shanks & Pottenger and the IATA agree except
# the IATA gives 1996-09-08. Go with Shanks & Pottenger.
# From Falkland Islands Government Office, London (2001-01-22)
# via Jesper Nørgaard:
# ... the clocks revert back to Local Mean Time at 2 am on Sunday 15
# April 2001 and advance one hour to summer time at 2 am on Sunday 2
# September. It is anticipated that the clocks will revert back at 2
# am on Sunday 21 April 2002 and advance to summer time at 2 am on
# Sunday 1 September.
# From Rives McDow (2001-02-13):
#
# I have communicated several times with people there, and the last
# time I had communications that was helpful was in 1998. Here is
# what was said then:
#
# "The general rule was that Stanley used daylight saving and the Camp
# did not. However for various reasons many people in the Camp have
# started to use daylight saving (known locally as 'Stanley Time')
# There is no rule as to who uses daylight saving - it is a matter of
# personal choice and so it is impossible to draw a map showing who
# uses it and who does not. Any list would be out of date as soon as
# it was produced. This year daylight saving ended on April 18/19th
# and started again on September 12/13th. I do not know what the rule
# is, but can find out if you like. We do not change at the same time
# as UK or Chile."
#
# I did have in my notes that the rule was "Second Saturday in Sep at
# 0:00 until third Saturday in Apr at 0:00". I think that this does
# not agree in some cases with Shanks; is this true?
#
# Also, there is no mention in the list that some areas in the
# Falklands do not use DST. I have found in my communications there
# that these areas are on the western half of East Falkland and all of
# West Falkland. Stanley is the only place that consistently observes
# DST. Again, as in other places in the world, the farmers don't like
# it. West Falkland is almost entirely sheep farmers.
#
# I know one lady there that keeps a list of which farm keeps DST and
# which doesn't each year. She runs a shop in Stanley, and says that
# the list changes each year. She uses it to communicate to her
# customers, catching them when they are home for lunch or dinner.
# From Paul Eggert (2001-03-05):
# For now, we'll just record the time in Stanley, since we have no
# better info.
# From Steffen Thorsen (2011-04-01):
# The Falkland Islands will not turn back clocks this winter, but stay on
# daylight saving time.
#
# One source:
# http://www.falklandnews.com/public/story.cfm?get=5914&source=3
#
# We have gotten this confirmed by a clerk of the legislative assembly:
# Normally the clocks revert to Local Mean Time (UTC/GMT -4 hours) on the
# third Sunday of April at 0200hrs and advance to Summer Time (UTC/GMT -3
# hours) on the first Sunday of September at 0200hrs.
#
# IMPORTANT NOTE: During 2011, on a trial basis, the Falkland Islands
# will not revert to local mean time, but clocks will remain on Summer
# time (UTC/GMT - 3 hours) throughout the whole of 2011. Any long term
# change to local time following the trial period will be notified.
#
# From Andrew Newman (2012-02-24)
# A letter from Justin McPhee, Chief Executive,
# Cable & Wireless Falkland Islands (dated 2012-02-22)
# states...
# The current Atlantic/Stanley entry under South America expects the
# clocks to go back to standard Falklands Time (FKT) on the 15th April.
# The database entry states that in 2011 Stanley was staying on fixed
# summer time on a trial basis only. FIG need to contact IANA and/or
# the maintainers of the database to inform them we're adopting
# the same policy this year and suggest recommendations for future years.
#
# For now we will assume permanent -03 for the Falklands
# until advised differently (to apply for 2012 and beyond, after the 2011
# experiment was apparently successful.)
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Falk 1937 1938 - Sep lastSun 0:00 1:00 -
Rule Falk 1938 1942 - Mar Sun>=19 0:00 0 -
Rule Falk 1939 only - Oct 1 0:00 1:00 -
Rule Falk 1940 1942 - Sep lastSun 0:00 1:00 -
Rule Falk 1943 only - Jan 1 0:00 0 -
Rule Falk 1983 only - Sep lastSun 0:00 1:00 -
Rule Falk 1984 1985 - Apr lastSun 0:00 0 -
Rule Falk 1984 only - Sep 16 0:00 1:00 -
Rule Falk 1985 2000 - Sep Sun>=9 0:00 1:00 -
Rule Falk 1986 2000 - Apr Sun>=16 0:00 0 -
Rule Falk 2001 2010 - Apr Sun>=15 2:00 0 -
Rule Falk 2001 2010 - Sep Sun>=1 2:00 1:00 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Atlantic/Stanley -3:51:24 - LMT 1890
-3:51:24 - SMT 1912 Mar 12 # Stanley Mean Time
-4:00 Falk -04/-03 1983 May
-3:00 Falk -03/-02 1985 Sep 15
-4:00 Falk -04/-03 2010 Sep 5 2:00
-3:00 - -03
# French Guiana
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Cayenne -3:29:20 - LMT 1911 Jul
-4:00 - -04 1967 Oct
-3:00 - -03
# Guyana
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Guyana -3:52:40 - LMT 1915 Mar # Georgetown
-3:45 - -0345 1975 Jul 31
-3:00 - -03 1991
# IATA SSIM (1996-06) says -4:00. Assume a 1991 switch.
-4:00 - -04
# Paraguay
#
# From Paul Eggert (2006-03-22):
# Shanks & Pottenger say that spring transitions are 01:00 -> 02:00,
# and autumn transitions are 00:00 -> 23:00. Go with pre-1999
# editions of Shanks, and with the IATA, who say transitions occur at 00:00.
#
# From Waldemar Villamayor-Venialbo (2013-09-20):
# No time of the day is established for the adjustment, so people normally
# adjust their clocks at 0 hour of the given dates.
#
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Para 1975 1988 - Oct 1 0:00 1:00 -
Rule Para 1975 1978 - Mar 1 0:00 0 -
Rule Para 1979 1991 - Apr 1 0:00 0 -
Rule Para 1989 only - Oct 22 0:00 1:00 -
Rule Para 1990 only - Oct 1 0:00 1:00 -
Rule Para 1991 only - Oct 6 0:00 1:00 -
Rule Para 1992 only - Mar 1 0:00 0 -
Rule Para 1992 only - Oct 5 0:00 1:00 -
Rule Para 1993 only - Mar 31 0:00 0 -
Rule Para 1993 1995 - Oct 1 0:00 1:00 -
Rule Para 1994 1995 - Feb lastSun 0:00 0 -
Rule Para 1996 only - Mar 1 0:00 0 -
# IATA SSIM (2000-02) says 1999-10-10; ignore this for now.
# From Steffen Thorsen (2000-10-02):
# I have three independent reports that Paraguay changed to DST this Sunday
# (10-01).
#
# Translated by Gwillim Law (2001-02-27) from
# Noticias, a daily paper in Asunción, Paraguay (2000-10-01):
# http://www.diarionoticias.com.py/011000/nacional/naciona1.htm
# Starting at 0:00 today, the clock will be set forward 60 minutes, in
# fulfillment of Decree No. 7,273 of the Executive Power.... The time change
# system has been operating for several years. Formerly there was a separate
# decree each year; the new law has the same effect, but permanently. Every
# year, the time will change on the first Sunday of October; likewise, the
# clock will be set back on the first Sunday of March.
#
Rule Para 1996 2001 - Oct Sun>=1 0:00 1:00 -
# IATA SSIM (1997-09) says Mar 1; go with Shanks & Pottenger.
Rule Para 1997 only - Feb lastSun 0:00 0 -
# Shanks & Pottenger say 1999-02-28; IATA SSIM (1999-02) says 1999-02-27, but
# (1999-09) reports no date; go with above sources and Gerd Knops (2001-02-27).
Rule Para 1998 2001 - Mar Sun>=1 0:00 0 -
# From Rives McDow (2002-02-28):
# A decree was issued in Paraguay (No. 16350) on 2002-02-26 that changed the
# dst method to be from the first Sunday in September to the first Sunday in
# April.
Rule Para 2002 2004 - Apr Sun>=1 0:00 0 -
Rule Para 2002 2003 - Sep Sun>=1 0:00 1:00 -
#
# From Jesper Nørgaard Welen (2005-01-02):
# There are several sources that claim that Paraguay made
# a timezone rule change in autumn 2004.
# From Steffen Thorsen (2005-01-05):
# Decree 1,867 (2004-03-05)
# From Carlos Raúl Perasso via Jesper Nørgaard Welen (2006-10-13)
# http://www.presidencia.gov.py/decretos/D1867.pdf
Rule Para 2004 2009 - Oct Sun>=15 0:00 1:00 -
Rule Para 2005 2009 - Mar Sun>=8 0:00 0 -
# From Carlos Raúl Perasso (2010-02-18):
# By decree number 3958 issued yesterday
# http://www.presidencia.gov.py/v1/wp-content/uploads/2010/02/decreto3958.pdf
# Paraguay changes its DST schedule, postponing the March rule to April and
# modifying the October date. The decree reads:
# ...
# Art. 1. It is hereby established that from the second Sunday of the month of
# April of this year (2010), the official time is to be set back 60 minutes,
# and that on the first Sunday of the month of October, it is to be set
# forward 60 minutes, in all the territory of the Paraguayan Republic.
# ...
Rule Para 2010 max - Oct Sun>=1 0:00 1:00 -
Rule Para 2010 2012 - Apr Sun>=8 0:00 0 -
#
# From Steffen Thorsen (2013-03-07):
# Paraguay will end DST on 2013-03-24 00:00....
# http://www.ande.gov.py/interna.php?id=1075
#
# From Carlos Raúl Perasso (2013-03-15):
# The change in Paraguay is now final. Decree number 10780
# http://www.presidencia.gov.py/uploads/pdf/presidencia-3b86ff4b691c79d4f5927ca964922ec74772ce857c02ca054a52a37b49afc7fb.pdf
# From Carlos Raúl Perasso (2014-02-28):
# Decree 1264 can be found at:
# http://www.presidencia.gov.py/archivos/documentos/DECRETO1264_ey9r8zai.pdf
Rule Para 2013 max - Mar Sun>=22 0:00 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Asuncion -3:50:40 - LMT 1890
-3:50:40 - AMT 1931 Oct 10 # Asunción Mean Time
-4:00 - -04 1972 Oct
-3:00 - -03 1974 Apr
-4:00 Para -04/-03
# Peru
#
# From Evelyn C. Leeper via Mark Brader (2003-10-26)
# <news:xrGmb.39935$gA1.13896113@news4.srv.hcvlny.cv.net>:
# When we were in Peru in 1985-1986, they apparently switched over
# sometime between December 29 and January 3 while we were on the Amazon.
#
# From Paul Eggert (2006-03-22):
# Shanks & Pottenger don't have this transition. Assume 1986 was like 1987.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Peru 1938 only - Jan 1 0:00 1:00 -
Rule Peru 1938 only - Apr 1 0:00 0 -
Rule Peru 1938 1939 - Sep lastSun 0:00 1:00 -
Rule Peru 1939 1940 - Mar Sun>=24 0:00 0 -
Rule Peru 1986 1987 - Jan 1 0:00 1:00 -
Rule Peru 1986 1987 - Apr 1 0:00 0 -
Rule Peru 1990 only - Jan 1 0:00 1:00 -
Rule Peru 1990 only - Apr 1 0:00 0 -
# IATA is ambiguous for 1993/1995; go with Shanks & Pottenger.
Rule Peru 1994 only - Jan 1 0:00 1:00 -
Rule Peru 1994 only - Apr 1 0:00 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Lima -5:08:12 - LMT 1890
-5:08:36 - LMT 1908 Jul 28 # Lima Mean Time?
-5:00 Peru -05/-04
# South Georgia
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Atlantic/South_Georgia -2:26:08 - LMT 1890 # Grytviken
-2:00 - -02
# South Sandwich Is
# uninhabited; scientific personnel have wintered
# Suriname
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Paramaribo -3:40:40 - LMT 1911
-3:40:52 - PMT 1935 # Paramaribo Mean Time
-3:40:36 - PMT 1945 Oct # The capital moved?
-3:30 - -0330 1984 Oct
-3:00 - -03
# Trinidad and Tobago
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Port_of_Spain -4:06:04 - LMT 1912 Mar 2
-4:00 - AST
# These all agree with Trinidad and Tobago since 1970.
Link America/Port_of_Spain America/Anguilla
Link America/Port_of_Spain America/Antigua
Link America/Port_of_Spain America/Dominica
Link America/Port_of_Spain America/Grenada
Link America/Port_of_Spain America/Guadeloupe
Link America/Port_of_Spain America/Marigot # St Martin (French part)
Link America/Port_of_Spain America/Montserrat
Link America/Port_of_Spain America/St_Barthelemy # St Barthélemy
Link America/Port_of_Spain America/St_Kitts # St Kitts & Nevis
Link America/Port_of_Spain America/St_Lucia
Link America/Port_of_Spain America/St_Thomas # Virgin Islands (US)
Link America/Port_of_Spain America/St_Vincent
Link America/Port_of_Spain America/Tortola # Virgin Islands (UK)
# Uruguay
# From Paul Eggert (1993-11-18):
# Uruguay wins the prize for the strangest peacetime manipulation of the rules.
#
# From Tim Parenti (2018-02-20), per Jeremie Bonjour (2018-01-31) and Michael
# Deckers (2018-02-20):
# ... At least they kept good records...
#
# http://www.armada.mil.uy/ContenidosPDFs/sohma/web/almanaque/almanaque_2018.pdf#page=36
# Page 36 of Almanaque 2018, published by the Oceanography, Hydrography, and
# Meteorology Service of the Uruguayan Navy, seems to give many transitions
# with greater clarity than we've had before. It directly references many laws
# and decrees which are, in turn, referenced below. They can be viewed in the
# public archives of the Diario Oficial (in Spanish) at
# http://www.impo.com.uy/diariooficial/
#
# Ley No. 3920 of 1908-06-10 placed the determination of legal time under the
# auspices of the National Institute for the Prediction of Time. It is unclear
# exactly what offset was used during this period, though Ley No. 7200 of
# 1920-04-23 used the Observatory of the National Meteorological Institute in
# Montevideo (34° 54' 33" S, 56° 12' 45" W) as its reference meridian,
# retarding legal time by 15 minutes 9 seconds from 1920-04-30 24:00,
# resulting in UT-04. Assume the corresponding LMT of UT-03:44:51 (given on
# page 725 of the Proceedings of the Second Pan-American Scientific Congress,
# 1915-1916) was in use, and merely became official from 1908-06-10.
# https://www.impo.com.uy/diariooficial/1908/06/18/12
# https://www.impo.com.uy/diariooficial/1920/04/27/9
#
# Ley No. 7594 of 1923-06-28 specified legal time as Observatory time advanced
# by 44 minutes 51 seconds (UT-03) "from 30 September to 31 March", and by 14
# minutes 51 seconds (UT-03:30) "the rest of the year"; a message from the
# National Council of Administration the same day, published directly below the
# law in the Diario Oficial, specified the first transition to be 1923-09-30
# 24:00. This effectively established standard time at UT-03:30 with 30
# minutes DST. Assume transitions at 24:00 on the specified days until Ley No.
# 7919 of 1926-03-05 ended this arrangement, repealing all "laws and other
# provisions which oppose" it, resulting in year-round UT-03:30; a Resolución
# of 1926-03-11 puts the final transition at 1926-03-31 24:00, the same as it
# would have been under the previous law.
# https://www.impo.com.uy/diariooficial/1923/07/02/2
# https://www.impo.com.uy/diariooficial/1926/03/10/2
# https://www.impo.com.uy/diariooficial/1926/03/18/2
#
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Uruguay 1923 1925 - Oct 1 0:00 0:30 -
Rule Uruguay 1924 1926 - Apr 1 0:00 0 -
# From Tim Parenti (2018-02-15):
# http://www.impo.com.uy/diariooficial/1933/10/27/6
#
# It appears Ley No. 9122 of 1933 was never published as such in the Diario
# Oficial, but instead appeared as Document 26 in the Diario on Friday
# 1933-10-27 as a decree made Monday 1933-10-23 and filed under the Ministry of
# National Defense. It reinstituted a DST of 30 minutes (to UT-03) "from the
# last Sunday of October...until the last Saturday of March." In accordance
# with this provision, the first transition was explicitly specified in Article
# 2 of the decree as Saturday 1933-10-28 at 24:00; that is, Sunday 1933-10-29
# at 00:00. Assume transitions at 00:00 Sunday throughout.
#
# Departing from the matter-of-fact nature of previous timekeeping laws, the
# 1933 decree "consider[s] the advantages of...the advance of legal time":
#
# "Whereas: The measure adopted by almost all nations at the time of the last
# World War still persists in North America and Europe, precisely because of
# the economic, hygienic, and social advantages derived from such an
# emergency measure...
#
# Whereas: The advance of the legal time during the summer seasons, by
# displacing social activity near sunrise, favors the citizen populations
# and especially the society that creates and works..."
#
# It further specified that "necessary measures" be taken to ensure that
# "public spectacles finish, in general, before [01:00]."
Rule Uruguay 1933 1938 - Oct lastSun 0:00 0:30 -
Rule Uruguay 1934 1941 - Mar lastSat 24:00 0 -
# From Tim Parenti (2018-02-15):
# Most of the Rules below, and their contemporaneous Zone lines, have been
# updated simply to match the Almanaque 2018. Although the document does not
# list exact transition times, midnight transitions were already present in our
# data here for all transitions through 2004-09, and this is both consistent
# with prior transitions and verified in several decrees marked below between
# 1939-09 and 2004-09, wherein the relevant text was typically of the form:
#
# "From 0 hours on [date], the legal time of the entire Republic will be...
#
# In accordance with [the preceding], on [previous date] at 24 hours, all
# clocks throughout the Republic will be [advanced/retarded] by..."
#
# It is possible that there is greater specificity to be found for the Rules
# below, but it is buried in no fewer than 40 different decrees individually
# referenced by the Almanaque for the period from 1939-09 to 2014-09.
# Four-fifths of these were promulgated less than two weeks before taking
# effect; more than half within a week and none more than 5 weeks. Only the
# handful with comments below have been checked with any thoroughness.
Rule Uruguay 1939 only - Oct 1 0:00 0:30 -
Rule Uruguay 1940 only - Oct 27 0:00 0:30 -
# From Tim Parenti (2018-02-15):
# Decreto 1145 of the Ministry of National Defense, dated 1941-07-26, specified
# UT-03 from Friday 1941-08-01 00:00, citing an "urgent...need to save fuel".
# http://www.impo.com.uy/diariooficial/1941/08/04/1
Rule Uruguay 1941 only - Aug 1 0:00 0:30 -
# From Tim Parenti (2018-02-15):
# Decreto 1866 of the Ministry of National Defense, dated 1942-12-09, specified
# further advancement (to UT-02:30) from Sunday 1942-12-13 24:00. Since clocks
# never went back to UT-03:30 thereafter, this is modeled as advancing standard
# time by 30 minutes to UT-03, while retaining 30 minutes of DST.
# http://www.impo.com.uy/diariooficial/1942/12/16/3
Rule Uruguay 1942 only - Dec 14 0:00 0:30 -
Rule Uruguay 1943 only - Mar 14 0:00 0 -
Rule Uruguay 1959 only - May 24 0:00 0:30 -
Rule Uruguay 1959 only - Nov 15 0:00 0 -
Rule Uruguay 1960 only - Jan 17 0:00 1:00 -
Rule Uruguay 1960 only - Mar 6 0:00 0 -
Rule Uruguay 1965 only - Apr 4 0:00 1:00 -
Rule Uruguay 1965 only - Sep 26 0:00 0 -
# From Tim Parenti (2018-02-15):
# Decreto 321/968 of 1968-05-25, citing emergency drought measures decreed the
# day before, brought clocks forward 30 minutes from Monday 1968-05-27 00:00.
# http://www.impo.com.uy/diariooficial/1968/05/30/5
Rule Uruguay 1968 only - May 27 0:00 0:30 -
Rule Uruguay 1968 only - Dec 1 0:00 0 -
# From Tim Parenti (2018-02-15):
# Decreto 188/970 of 1970-04-23 instituted restrictions on electricity
# consumption "as a consequence of the current rainfall regime in the country".
# Articles 13 and 14 advanced clocks by an hour from Saturday 1970-04-25 00:00.
# http://www.impo.com.uy/diariooficial/1970/04/29/4
Rule Uruguay 1970 only - Apr 25 0:00 1:00 -
Rule Uruguay 1970 only - Jun 14 0:00 0 -
Rule Uruguay 1972 only - Apr 23 0:00 1:00 -
Rule Uruguay 1972 only - Jul 16 0:00 0 -
# From Tim Parenti (2018-02-15):
# Decreto 29/974 of 1974-01-11, citing "the international rise in the price of
# oil", advanced clocks by 90 minutes (to UT-01:30). Decreto 163/974 of
# 1974-03-04 returned 60 of those minutes (to UT-02:30), and the remaining 30
# minutes followed in Decreto 679/974 of 1974-08-29.
# http://www.impo.com.uy/diariooficial/1974/01/22/11
# http://www.impo.com.uy/diariooficial/1974/03/14/3
# http://www.impo.com.uy/diariooficial/1974/09/04/6
Rule Uruguay 1974 only - Jan 13 0:00 1:30 -
Rule Uruguay 1974 only - Mar 10 0:00 0:30 -
Rule Uruguay 1974 only - Sep 1 0:00 0 -
Rule Uruguay 1974 only - Dec 22 0:00 1:00 -
Rule Uruguay 1975 only - Mar 30 0:00 0 -
Rule Uruguay 1976 only - Dec 19 0:00 1:00 -
Rule Uruguay 1977 only - Mar 6 0:00 0 -
Rule Uruguay 1977 only - Dec 4 0:00 1:00 -
Rule Uruguay 1978 1979 - Mar Sun>=1 0:00 0 -
Rule Uruguay 1978 only - Dec 17 0:00 1:00 -
Rule Uruguay 1979 only - Apr 29 0:00 1:00 -
Rule Uruguay 1980 only - Mar 16 0:00 0 -
# From Tim Parenti (2018-02-15):
# Decreto 725/987 of 1987-12-04 cited "better use of national tourist
# attractions" to advance clocks one hour from Monday 1987-12-14 00:00.
# http://www.impo.com.uy/diariooficial/1988/01/25/1
Rule Uruguay 1987 only - Dec 14 0:00 1:00 -
Rule Uruguay 1988 only - Feb 28 0:00 0 -
Rule Uruguay 1988 only - Dec 11 0:00 1:00 -
Rule Uruguay 1989 only - Mar 5 0:00 0 -
Rule Uruguay 1989 only - Oct 29 0:00 1:00 -
Rule Uruguay 1990 only - Feb 25 0:00 0 -
# From Tim Parenti (2018-02-15), per Paul Eggert (1999-11-04):
# IATA agrees as below for 1990-10 through 1993-02. Per Almanaque 2018, the
# 1992/1993 season appears to be the first in over half a century where DST
# both began and ended pursuant to the same decree.
Rule Uruguay 1990 1991 - Oct Sun>=21 0:00 1:00 -
Rule Uruguay 1991 1992 - Mar Sun>=1 0:00 0 -
Rule Uruguay 1992 only - Oct 18 0:00 1:00 -
Rule Uruguay 1993 only - Feb 28 0:00 0 -
# From Eduardo Cota (2004-09-20):
# The Uruguayan government has decreed a change in the local time....
# From Tim Parenti (2018-02-15):
# Decreto 328/004 of 2004-09-15.
# http://www.impo.com.uy/diariooficial/2004/09/23/documentos.pdf#page=1
Rule Uruguay 2004 only - Sep 19 0:00 1:00 -
# From Steffen Thorsen (2005-03-11):
# Uruguay's DST was scheduled to end on Sunday, 2005-03-13, but in order to
# save energy ... it was postponed two weeks....
# From Tim Parenti (2018-02-15):
# This 2005 postponement is not in Almanaque 2018. Go with the contemporaneous
# reporting, which is confirmed by Decreto 107/005 of 2005-03-10 amending
# Decreto 328/004:
# http://www.impo.com.uy/diariooficial/2005/03/15/documentos.pdf#page=1
# The original decree specified a transition of 2005-03-12 24:00, but the new
# one specified 2005-03-27 02:00.
Rule Uruguay 2005 only - Mar 27 2:00 0 -
# From Eduardo Cota (2005-09-27):
# ...from 2005-10-09 at 02:00 local time, until 2006-03-12 at 02:00 local time,
# official time in Uruguay will be at GMT -2.
# From Tim Parenti (2018-02-15):
# Decreto 318/005 of 2005-09-19.
# http://www.impo.com.uy/diariooficial/2005/09/23/documentos.pdf#page=1
Rule Uruguay 2005 only - Oct 9 2:00 1:00 -
Rule Uruguay 2006 2015 - Mar Sun>=8 2:00 0 -
# From Tim Parenti (2018-02-15), per Jesper Nørgaard Welen (2006-09-06):
# Decreto 311/006 of 2006-09-04 established regular DST from the first Sunday
# of October at 02:00 through the second Sunday of March at 02:00. Almanaque
# 2018 appears to have a few typoed dates through this period; ignore them.
# http://www.impo.com.uy/diariooficial/2006/09/08/documentos.pdf#page=1
Rule Uruguay 2006 2014 - Oct Sun>=1 2:00 1:00 -
# From Steffen Thorsen (2015-06-30):
# ... it looks like they will not be using DST the coming summer:
# http://www.elobservador.com.uy/gobierno-resolvio-que-no-habra-cambio-horario-verano-n656787
# http://www.republica.com.uy/este-ano-no-se-modificara-el-huso-horario-en-uruguay/523760/
# From Paul Eggert (2015-06-30):
# Apparently restaurateurs complained that DST caused people to go to the beach
# instead of out to dinner.
# From Pablo Camargo (2015-07-13):
# http://archivo.presidencia.gub.uy/sci/decretos/2015/06/cons_min_201.pdf
# From Tim Parenti (2018-02-15):
# Decreto 178/015 of 2015-06-29; repeals Decreto 311/006.
# This Zone can be simplified once we assume zic %z.
Zone America/Montevideo -3:44:51 - LMT 1908 Jun 10
-3:44:51 - MMT 1920 May 1 # Montevideo MT
-4:00 - -04 1923 Oct 1
-3:30 Uruguay -0330/-03 1942 Dec 14
-3:00 Uruguay -03/-0230 1960
-3:00 Uruguay -03/-02 1968
-3:00 Uruguay -03/-0230 1970
-3:00 Uruguay -03/-02 1974
-3:00 Uruguay -03/-0130 1974 Mar 10
-3:00 Uruguay -03/-0230 1974 Dec 22
-3:00 Uruguay -03/-02
# Venezuela
#
# From Paul Eggert (2015-07-28):
# For the 1965 transition see Gaceta Oficial No. 27.619 (1964-12-15), p 205.533
# http://www.pgr.gob.ve/dmdocuments/1964/27619.pdf
#
# From John Stainforth (2007-11-28):
# ... the change for Venezuela originally expected for 2007-12-31 has
# been brought forward to 2007-12-09. The official announcement was
# published today in the "Gaceta Oficial de la República Bolivariana
# de Venezuela, número 38.819" (official document for all laws or
# resolution publication)
# http://www.globovision.com/news.php?nid=72208
# From Alexander Krivenyshev (2016-04-15):
# https://actualidad.rt.com/actualidad/204758-venezuela-modificar-huso-horario-sequia-elnino
#
# From Paul Eggert (2016-04-15):
# Clocks advance 30 minutes on 2016-05-01 at 02:30....
# "'Venezuela's new time-zone: hours without light, hours without water,
# hours of presidential broadcasts, hours of lines,' quipped comedian
# Jean Mary Curró ...". See: Cawthorne A, Kai D. Venezuela scraps
# half-hour time difference set by Chavez. Reuters 2016-04-15 14:50 -0400
# https://www.reuters.com/article/us-venezuela-timezone-idUSKCN0XC2BE
#
# From Matt Johnson (2016-04-20):
# ... published in the official Gazette [2016-04-18], here:
# http://historico.tsj.gob.ve/gaceta_ext/abril/1842016/E-1842016-4551.pdf
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Caracas -4:27:44 - LMT 1890
-4:27:40 - CMT 1912 Feb 12 # Caracas Mean Time?
-4:30 - -0430 1965 Jan 1 0:00
-4:00 - -04 2007 Dec 9 3:00
-4:30 - -0430 2016 May 1 2:30
-4:00 - -04
Index: stable/12/contrib/tzdata/theory.html
===================================================================
--- stable/12/contrib/tzdata/theory.html (revision 352352)
+++ stable/12/contrib/tzdata/theory.html (revision 352353)
@@ -1,1385 +1,1452 @@
<!DOCTYPE html>
<html lang="en">
<head>
<title>Theory and pragmatics of the tz code and data</title>
<meta charset="UTF-8">
<style>
pre {margin-left: 2em; white-space: pre-wrap;}
</style>
</head>
<body>
<h1>Theory and pragmatics of the <code><abbr>tz</abbr></code> code and data</h1>
<h3>Outline</h3>
<nav>
<ul>
<li><a href="#scope">Scope of the <code><abbr>tz</abbr></code>
database</a></li>
<li><a href="#naming">Timezone identifiers</a></li>
<li><a href="#abbreviations">Time zone abbreviations</a></li>
<li><a href="#accuracy">Accuracy of the <code><abbr>tz</abbr></code>
database</a></li>
<li><a href="#functions">Time and date functions</a></li>
<li><a href="#stability">Interface stability</a></li>
+ <li><a href="#leapsec">Leap seconds</a></li>
<li><a href="#calendar">Calendrical issues</a></li>
<li><a href="#planets">Time and time zones on other planets</a></li>
</ul>
</nav>
<section>
<h2 id="scope">Scope of the <code><abbr>tz</abbr></code> database</h2>
<p>
The <a
href="https://www.iana.org/time-zones"><code><abbr>tz</abbr></code>
database</a> attempts to record the history and predicted future of
all computer-based clocks that track civil time.
It organizes <a href="tz-link.html">time zone and daylight saving time
data</a> by partitioning the world into <a
href="https://en.wikipedia.org/wiki/List_of_tz_database_time_zones"><dfn>timezones</dfn></a>
whose clocks all agree about timestamps that occur after the <a
href="https://en.wikipedia.org/wiki/Unix_time">POSIX Epoch</a>
(1970-01-01 00:00:00 <a
href="https://en.wikipedia.org/wiki/Coordinated_Universal_Time"><abbr
title="Coordinated Universal Time">UTC</abbr></a>).
The database labels each timezone with a notable location and
records all known clock transitions for that location.
Although 1970 is a somewhat-arbitrary cutoff, there are significant
challenges to moving the cutoff earlier even by a decade or two, due
to the wide variety of local practices before computer timekeeping
became prevalent.
</p>
<p>
Each timezone typically corresponds to a geographical region that is
smaller than a traditional time zone, because clocks in a timezone
all agree after 1970 whereas a traditional time zone merely
specifies current standard time. For example, applications that deal
with current and future timestamps in the traditional North
American mountain time zone can choose from the timezones
<code>America/Denver</code> which observes US-style daylight saving
time, <code>America/Mazatlan</code> which observes Mexican-style DST,
and <code>America/Phoenix</code> which does not observe DST.
Applications that also deal with past timestamps in the mountain time
zone can choose from over a dozen timezones, such as
<code>America/Boise</code>, <code>America/Edmonton</code>, and
<code>America/Hermosillo</code>, each of which currently uses mountain
time but differs from other timezones for some timestamps after 1970.
</p>
<p>
Clock transitions before 1970 are recorded for each timezone,
because most systems support timestamps before 1970 and could
misbehave if data entries were omitted for pre-1970 transitions.
However, the database is not designed for and does not suffice for
applications requiring accurate handling of all past times everywhere,
as it would take far too much effort and guesswork to record all
details of pre-1970 civil timekeeping.
Although some information outside the scope of the database is
collected in a file <code>backzone</code> that is distributed along
with the database proper, this file is less reliable and does not
necessarily follow database guidelines.
</p>
<p>
As described below, reference source code for using the
<code><abbr>tz</abbr></code> database is also available.
The <code><abbr>tz</abbr></code> code is upwards compatible with <a
href="https://en.wikipedia.org/wiki/POSIX">POSIX</a>, an international
standard for <a
href="https://en.wikipedia.org/wiki/Unix">UNIX</a>-like systems.
As of this writing, the current edition of POSIX is: <a
href="https://pubs.opengroup.org/onlinepubs/9699919799/"> The Open
Group Base Specifications Issue 7</a>, IEEE Std 1003.1-2017, 2018
Edition.
Because the database's scope encompasses real-world changes to civil
timekeeping, its model for describing time is more complex than the
standard and daylight saving times supported by POSIX.
A <code><abbr>tz</abbr></code> timezone corresponds to a ruleset that can
have more than two changes per year, these changes need not merely
flip back and forth between two alternatives, and the rules themselves
can change at times.
-Whether and when a timezone changes its
-clock, and even the timezone's notional base offset from UTC, are variable.
+Whether and when a timezone changes its clock,
+and even the timezone's notional base offset from <abbr>UTC</abbr>,
+are variable.
It does not always make sense to talk about a timezone's
"base offset", which is not necessarily a single number.
</p>
</section>
<section>
<h2 id="naming">Timezone identifiers</h2>
<p>
Each timezone has a name that uniquely identifies the timezone.
Inexperienced users are not expected to select these names unaided.
Distributors should provide documentation and/or a simple selection
interface that explains each name via a map or via descriptive text like
"Ruthenia" instead of the timezone name "<code>Europe/Uzhgorod</code>".
If geolocation information is available, a selection interface can
locate the user on a timezone map or prioritize names that are
geographically close. For an example selection interface, see the
<code>tzselect</code> program in the <code><abbr>tz</abbr></code> code.
The <a href="http://cldr.unicode.org/">Unicode Common Locale Data
Repository</a> contains data that may be useful for other selection
interfaces; it maps timezone names like <code>Europe/Uzhgorod</code>
to CLDR names like <code>uauzh</code> which are in turn mapped to
locale-dependent strings like "Uzhhorod", "Ungvár", "Ужгород", and
"乌日哥罗德".
</p>
<p>
The naming conventions attempt to strike a balance
among the following goals:
</p>
<ul>
<li>
Uniquely identify every timezone where clocks have agreed since 1970.
This is essential for the intended use: static clocks keeping local
civil time.
</li>
<li>
Indicate to experts where the timezone's clocks typically are.
</li>
<li>
Be robust in the presence of political changes.
For example, names are typically not tied to countries, to avoid
incompatibilities when countries change their name (e.g.,
Swaziland&rarr;Eswatini) or when locations change countries (e.g., Hong
Kong from UK colony to China).
There is no requirement that every country or national
capital must have a timezone name.
</li>
<li>
Be portable to a wide variety of implementations.
</li>
<li>
Use a consistent naming conventions over the entire world.
</li>
</ul>
<p>
Names normally have the form
<var>AREA</var><code>/</code><var>LOCATION</var>, where
<var>AREA</var> is a continent or ocean, and
<var>LOCATION</var> is a specific location within the area.
North and South America share the same area, '<code>America</code>'.
Typical names are '<code>Africa/Cairo</code>',
'<code>America/New_York</code>', and '<code>Pacific/Honolulu</code>'.
Some names are further qualified to help avoid confusion; for example,
'<code>America/Indiana/Petersburg</code>' distinguishes Petersburg,
Indiana from other Petersburgs in America.
</p>
<p>
Here are the general guidelines used for
choosing timezone names,
in decreasing order of importance:
</p>
<ul>
<li>
Use only valid POSIX file name components (i.e., the parts of
names other than '<code>/</code>').
Do not use the file name components '<code>.</code>' and
'<code>..</code>'.
Within a file name component, use only <a
href="https://en.wikipedia.org/wiki/ASCII">ASCII</a> letters,
'<code>.</code>', '<code>-</code>' and '<code>_</code>'.
Do not use digits, as that might create an ambiguity with <a
href="https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap08.html#tag_08_03">POSIX
<code>TZ</code> strings</a>.
A file name component must not exceed 14 characters or start with
'<code>-</code>'.
E.g., prefer <code>Asia/Brunei</code> to
<code>Asia/Bandar_Seri_Begawan</code>.
Exceptions: see the discussion of legacy names below.
</li>
<li>
A name must not be empty, or contain '<code>//</code>', or
start or end with '<code>/</code>'.
</li>
<li>
Do not use names that differ only in case.
Although the reference implementation is case-sensitive, some
other implementations are not, and they would mishandle names
differing only in case.
</li>
<li>
If one name <var>A</var> is an initial prefix of another
name <var>AB</var> (ignoring case), then <var>B</var> must not
start with '<code>/</code>', as a regular file cannot have the
same name as a directory in POSIX.
For example, <code>America/New_York</code> precludes
<code>America/New_York/Bronx</code>.
</li>
<li>
Uninhabited regions like the North Pole and Bouvet Island
do not need locations, since local time is not defined there.
</li>
<li>
If all the clocks in a timezone have agreed since 1970,
do not bother to include more than one timezone
even if some of the clocks disagreed before 1970.
Otherwise these tables would become annoyingly large.
</li>
<li>
If boundaries between regions are fluid, such as during a war or
insurrection, do not bother to create a new timezone merely
because of yet another boundary change. This helps prevent table
bloat and simplifies maintenance.
</li>
<li>
If a name is ambiguous, use a less ambiguous alternative;
e.g., many cities are named San José and Georgetown, so
prefer <code>America/Costa_Rica</code> to
<code>America/San_Jose</code> and <code>America/Guyana</code>
to <code>America/Georgetown</code>.
</li>
<li>
Keep locations compact.
Use cities or small islands, not countries or regions, so that any
future changes do not split individual locations into different
timezones.
E.g., prefer <code>Europe/Paris</code> to <code>Europe/France</code>,
since
<a href="https://en.wikipedia.org/wiki/Time_in_France#History">France
has had multiple time zones</a>.
</li>
<li>
Use mainstream English spelling, e.g., prefer
<code>Europe/Rome</code> to <code>Europa/Roma</code>, and
prefer <code>Europe/Athens</code> to the Greek
<code>Ευρώπη/Αθήνα</code> or the Romanized
<code>Evrópi/Athína</code>.
The POSIX file name restrictions encourage this guideline.
</li>
<li>
Use the most populous among locations in a region,
e.g., prefer <code>Asia/Shanghai</code> to
<code>Asia/Beijing</code>.
Among locations with similar populations, pick the best-known
location, e.g., prefer <code>Europe/Rome</code> to
<code>Europe/Milan</code>.
</li>
<li>
Use the singular form, e.g., prefer <code>Atlantic/Canary</code> to
<code>Atlantic/Canaries</code>.
</li>
<li>
Omit common suffixes like '<code>_Islands</code>' and
'<code>_City</code>', unless that would lead to ambiguity.
E.g., prefer <code>America/Cayman</code> to
<code>America/Cayman_Islands</code> and
<code>America/Guatemala</code> to
<code>America/Guatemala_City</code>, but prefer
<code>America/Mexico_City</code> to
<code>America/Mexico</code>
because <a href="https://en.wikipedia.org/wiki/Time_in_Mexico">the
country of Mexico has several time zones</a>.
</li>
<li>
Use '<code>_</code>' to represent a space.
</li>
<li>
Omit '<code>.</code>' from abbreviations in names.
E.g., prefer <code>Atlantic/St_Helena</code> to
<code>Atlantic/St._Helena</code>.
</li>
<li>
Do not change established names if they only marginally violate
the above guidelines.
For example, do not change the existing name <code>Europe/Rome</code> to
<code>Europe/Milan</code> merely because Milan's population has grown
to be somewhat greater than Rome's.
</li>
<li>
If a name is changed, put its old spelling in the
'<code>backward</code>' file.
This means old spellings will continue to work.
</li>
</ul>
<p>
Guidelines have evolved with time, and names following old versions of
these guidelines might not follow the current version. When guidelines
have changed, old names continue to be supported. Guideline changes
have included the following:
</p>
<ul>
<li>
Older versions of this package used a different naming scheme.
See the file '<code>backward</code>' for most of these older names
(e.g., '<code>US/Eastern</code>' instead of '<code>America/New_York</code>').
The other old-fashioned names still supported are
'<code>WET</code>', '<code>CET</code>', '<code>MET</code>', and
'<code>EET</code>' (see the file '<code>europe</code>').
</li>
<li>
Older versions of this package defined legacy names that are
incompatible with the first guideline of location names, but which are
still supported.
These legacy names are mostly defined in the file
'<code>etcetera</code>'.
Also, the file '<code>backward</code>' defines the legacy names
'<code>GMT0</code>', '<code>GMT-0</code>' and '<code>GMT+0</code>',
and the file '<code>northamerica</code>' defines the legacy names
'<code>EST5EDT</code>', '<code>CST6CDT</code>',
'<code>MST7MDT</code>', and '<code>PST8PDT</code>'.
</li>
<li>
Older versions of these guidelines said that
there should typically be at least one name for each <a
href="https://en.wikipedia.org/wiki/ISO_3166-1"><abbr
title="International Organization for Standardization">ISO</abbr>
3166-1</a> officially assigned two-letter code for an inhabited
country or territory.
This old guideline has been dropped, as it was not needed to handle
timestamps correctly and it increased maintenance burden.
</li>
</ul>
<p>
The file '<code>zone1970.tab</code>' lists geographical locations used
to name timezones.
It is intended to be an exhaustive list of names for geographic
regions as described above; this is a subset of the timezones in the data.
Although a '<code>zone1970.tab</code>' location's
<a href="https://en.wikipedia.org/wiki/Longitude">longitude</a>
corresponds to
its <a href="https://en.wikipedia.org/wiki/Local_mean_time">local mean
time (<abbr>LMT</abbr>)</a> offset with one hour for every 15&deg;
east longitude, this relationship is not exact.
</p>
<p>
Excluding '<code>backward</code>' should not affect the other data.
If '<code>backward</code>' is excluded, excluding
'<code>etcetera</code>' should not affect the remaining data.
</p>
</section>
<section>
<h2 id="abbreviations">Time zone abbreviations</h2>
<p>
When this package is installed, it generates time zone abbreviations
like '<code>EST</code>' to be compatible with human tradition and POSIX.
Here are the general guidelines used for choosing time zone abbreviations,
in decreasing order of importance:
</p>
<ul>
<li>
Use three to six characters that are ASCII alphanumerics or
'<code>+</code>' or '<code>-</code>'.
Previous editions of this database also used characters like
space and '<code>?</code>', but these characters have a
special meaning to the
<a href="https://en.wikipedia.org/wiki/Unix_shell">UNIX shell</a>
and cause commands like
'<code><a href="https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set">set</a>
`<a href="https://pubs.opengroup.org/onlinepubs/9699919799/utilities/date.html">date</a>`</code>'
to have unexpected effects.
Previous editions of this guideline required upper-case letters, but the
Congressman who introduced
<a href="https://en.wikipedia.org/wiki/Chamorro_Time_Zone">Chamorro
Standard Time</a> preferred "ChST", so lower-case letters are now
allowed.
Also, POSIX from 2001 on relaxed the rule to allow '<code>-</code>',
'<code>+</code>', and alphanumeric characters from the portable
character set in the current locale.
In practice ASCII alphanumerics and '<code>+</code>' and
'<code>-</code>' are safe in all locales.
<p>
In other words, in the C locale the POSIX extended regular
expression <code>[-+[:alnum:]]{3,6}</code> should match the
abbreviation.
This guarantees that all abbreviations could have been specified by a
POSIX <code>TZ</code> string.
</p>
</li>
<li>
Use abbreviations that are in common use among English-speakers,
e.g., 'EST' for Eastern Standard Time in North America.
We assume that applications translate them to other languages
as part of the normal localization process; for example,
a French application might translate 'EST' to 'HNE'.
<p>
<small>These abbreviations (for standard/daylight/etc. time) are:
ACST/ACDT Australian Central,
AST/ADT/APT/AWT/ADDT Atlantic,
AEST/AEDT Australian Eastern,
AHST/AHDT Alaska-Hawaii,
AKST/AKDT Alaska,
AWST/AWDT Australian Western,
BST/BDT Bering,
CAT/CAST Central Africa,
CET/CEST/CEMT Central European,
ChST Chamorro,
CST/CDT/CWT/CPT/CDDT Central [North America],
CST/CDT China,
GMT/BST/IST/BDST Greenwich,
EAT East Africa,
EST/EDT/EWT/EPT/EDDT Eastern [North America],
EET/EEST Eastern European,
GST/GDT Guam,
HST/HDT/HWT/HPT Hawaii,
- HKT/HKST Hong Kong,
+ HKT/HKST/HKWT Hong Kong,
IST India,
IST/GMT Irish,
IST/IDT/IDDT Israel,
JST/JDT Japan,
KST/KDT Korea,
MET/MEST Middle European (a backward-compatibility alias for
Central European),
MSK/MSD Moscow,
MST/MDT/MWT/MPT/MDDT Mountain,
NST/NDT/NWT/NPT/NDDT Newfoundland,
NST/NDT/NWT/NPT Nome,
NZMT/NZST New Zealand through 1945,
NZST/NZDT New Zealand 1946&ndash;present,
PKT/PKST Pakistan,
PST/PDT/PWT/PPT/PDDT Pacific,
PST/PDT Philippine,
SAST South Africa,
SST Samoa,
WAT/WAST West Africa,
WET/WEST/WEMT Western European,
WIB Waktu Indonesia Barat,
WIT Waktu Indonesia Timur,
WITA Waktu Indonesia Tengah,
YST/YDT/YWT/YPT/YDDT Yukon</small>.
</p>
</li>
<li>
<p>
For times taken from a city's longitude, use the
traditional <var>x</var>MT notation.
The only abbreviation like this in current use is '<abbr>GMT</abbr>'.
The others are for timestamps before 1960,
except that Monrovia Mean Time persisted until 1972.
Typically, numeric abbreviations (e.g., '<code>-</code>004430' for
MMT) would cause trouble here, as the numeric strings would exceed
the POSIX length limit.
</p>
<p>
<small>These abbreviations are:
AMT Amsterdam, Asunción, Athens;
BMT Baghdad, Bangkok, Batavia, Bern, Bogotá, Bridgetown, Brussels,
Bucharest;
CMT Calamarca, Caracas, Chisinau, Colón, Copenhagen, Córdoba;
DMT Dublin/Dunsink;
EMT Easter;
FFMT Fort-de-France;
FMT Funchal;
GMT Greenwich;
HMT Havana, Helsinki, Horta, Howrah;
IMT Irkutsk, Istanbul;
JMT Jerusalem;
KMT Kaunas, Kiev, Kingston;
LMT Lima, Lisbon, local, Luanda;
MMT Macassar, Madras, Malé, Managua, Minsk, Monrovia, Montevideo,
Moratuwa, Moscow;
PLMT Phù Liễn;
PMT Paramaribo, Paris, Perm, Pontianak, Prague;
PMMT Port Moresby;
QMT Quito;
RMT Rangoon, Riga, Rome;
SDMT Santo Domingo;
SJMT San José;
SMT Santiago, Simferopol, Singapore, Stanley;
TBMT Tbilisi;
TMT Tallinn, Tehran;
WMT Warsaw</small>.
</p>
<p>
<small>A few abbreviations also follow the pattern that
<abbr>GMT</abbr>/<abbr>BST</abbr> established for time in the UK.
They are:
CMT/BST for Calamarca Mean Time and Bolivian Summer Time
1890&ndash;1932,
DMT/IST for Dublin/Dunsink Mean Time and Irish Summer Time
1880&ndash;1916,
MMT/MST/MDST for Moscow 1880&ndash;1919, and
RMT/LST for Riga Mean Time and Latvian Summer time 1880&ndash;1926.
An extra-special case is SET for Swedish Time (<em>svensk
normaltid</em>) 1879&ndash;1899, 3&deg; west of the Stockholm
Observatory.</small>
</p>
</li>
<li>
Use '<abbr>LMT</abbr>' for local mean time of locations before the
introduction of standard time; see "<a href="#scope">Scope of the
<code><abbr>tz</abbr></code> database</a>".
</li>
<li>
If there is no common English abbreviation, use numeric offsets like
<code>-</code>05 and <code>+</code>0530 that are generated
by <code>zic</code>'s <code>%z</code> notation.
</li>
<li>
Use current abbreviations for older timestamps to avoid confusion.
For example, in 1910 a common English abbreviation for time
in central Europe was 'MEZ' (short for both "Middle European
Zone" and for "Mitteleuropäische Zeit" in German).
Nowadays 'CET' ("Central European Time") is more common in
English, and the database uses 'CET' even for circa-1910
timestamps as this is less confusing for modern users and avoids
the need for determining when 'CET' supplanted 'MEZ' in common
usage.
</li>
<li>
Use a consistent style in a timezone's history.
For example, if a history tends to use numeric
abbreviations and a particular entry could go either way, use a
numeric abbreviation.
</li>
<li>
Use
<a href="https://en.wikipedia.org/wiki/Universal_Time">Universal Time</a>
(<abbr>UT</abbr>) (with time zone abbreviation '<code>-</code>00') for
locations while uninhabited.
The leading '<code>-</code>' is a flag that the <abbr>UT</abbr> offset is in
some sense undefined; this notation is derived
from <a href="https://tools.ietf.org/html/rfc3339">Internet
<abbr title="Request For Comments">RFC</abbr> 3339</a>.
</li>
</ul>
<p>
Application writers should note that these abbreviations are ambiguous
in practice: e.g., 'CST' means one thing in China and something else
in North America, and 'IST' can refer to time in India, Ireland or
Israel.
To avoid ambiguity, use numeric <abbr>UT</abbr> offsets like
'<code>-</code>0600' instead of time zone abbreviations like 'CST'.
</p>
</section>
<section>
<h2 id="accuracy">Accuracy of the <code><abbr>tz</abbr></code> database</h2>
<p>
The <code><abbr>tz</abbr></code> database is not authoritative, and it
surely has errors.
Corrections are welcome and encouraged; see the file <code>CONTRIBUTING</code>.
Users requiring authoritative data should consult national standards
bodies and the references cited in the database's comments.
</p>
<p>
Errors in the <code><abbr>tz</abbr></code> database arise from many sources:
</p>
<ul>
<li>
The <code><abbr>tz</abbr></code> database predicts future
timestamps, and current predictions
will be incorrect after future governments change the rules.
For example, if today someone schedules a meeting for 13:00 next
October 1, Casablanca time, and tomorrow Morocco changes its
daylight saving rules, software can mess up after the rule change
if it blithely relies on conversions made before the change.
</li>
<li>
The pre-1970 entries in this database cover only a tiny sliver of how
clocks actually behaved; the vast majority of the necessary
information was lost or never recorded.
Thousands more timezones would be needed if
the <code><abbr>tz</abbr></code> database's scope were extended to
cover even just the known or guessed history of standard time; for
example, the current single entry for France would need to split
into dozens of entries, perhaps hundreds.
And in most of the world even this approach would be misleading
due to widespread disagreement or indifference about what times
should be observed.
In her 2015 book
<cite><a
href="http://www.hup.harvard.edu/catalog.php?isbn=9780674286146">The
Global Transformation of Time, 1870&ndash;1950</a></cite>,
Vanessa Ogle writes
"Outside of Europe and North America there was no system of time
zones at all, often not even a stable landscape of mean times,
prior to the middle decades of the twentieth century".
See: Timothy Shenk, <a
href="https://www.dissentmagazine.org/blog/booked-a-global-history-of-time-vanessa-ogle">Booked:
A Global History of Time</a>. <cite>Dissent</cite> 2015-12-17.
</li>
<li>
Most of the pre-1970 data entries come from unreliable sources, often
astrology books that lack citations and whose compilers evidently
invented entries when the true facts were unknown, without
reporting which entries were known and which were invented.
These books often contradict each other or give implausible entries,
and on the rare occasions when they are checked they are
typically found to be incorrect.
</li>
<li>
For the UK the <code><abbr>tz</abbr></code> database relies on
years of first-class work done by
Joseph Myers and others; see
"<a href="https://www.polyomino.org.uk/british-time/">History of
legal time in Britain</a>".
Other countries are not done nearly as well.
</li>
<li>
Sometimes, different people in the same city maintain clocks
that differ significantly.
Historically, railway time was used by railroad companies (which
did not always
agree with each other), church-clock time was used for birth
certificates, etc.
More recently, competing political groups might disagree about
clock settings. Often this is merely common practice, but
sometimes it is set by law.
For example, from 1891 to 1911 the <abbr>UT</abbr> offset in France
was legally <abbr>UT</abbr> +00:09:21 outside train stations and
<abbr>UT</abbr> +00:04:21 inside. Other examples include
Chillicothe in 1920, Palm Springs in 1946/7, and Jerusalem and
Ürümqi to this day.
</li>
<li>
Although a named location in the <code><abbr>tz</abbr></code>
database stands for the containing region, its pre-1970 data
entries are often accurate for only a small subset of that region.
For example, <code>Europe/London</code> stands for the United
Kingdom, but its pre-1847 times are valid only for locations that
have London's exact meridian, and its 1847 transition
to <abbr>GMT</abbr> is known to be valid only for the L&amp;NW and
the Caledonian railways.
</li>
<li>
The <code><abbr>tz</abbr></code> database does not record the
earliest time for which a timezone's
data entries are thereafter valid for every location in the region.
For example, <code>Europe/London</code> is valid for all locations
in its region after <abbr>GMT</abbr> was made the standard time,
but the date of standardization (1880-08-02) is not in the
<code><abbr>tz</abbr></code> database, other than in commentary.
For many timezones the earliest time of
validity is unknown.
</li>
<li>
The <code><abbr>tz</abbr></code> database does not record a
region's boundaries, and in many cases the boundaries are not known.
For example, the timezone
<code>America/Kentucky/Louisville</code> represents a region
around the city of Louisville, the boundaries of which are
unclear.
</li>
<li>
Changes that are modeled as instantaneous transitions in the
<code><abbr>tz</abbr></code>
database were often spread out over hours, days, or even decades.
</li>
<li>
Even if the time is specified by law, locations sometimes
deliberately flout the law.
</li>
<li>
Early timekeeping practices, even assuming perfect clocks, were
often not specified to the accuracy that the
<code><abbr>tz</abbr></code> database requires.
</li>
<li>
Sometimes historical timekeeping was specified more precisely
than what the <code><abbr>tz</abbr></code> code can handle.
For example, from 1909 to 1937 <a
href="https://www.staff.science.uu.nl/~gent0113/wettijd/wettijd.htm"
hreflang="nl">Netherlands clocks</a> were legally Amsterdam Mean
Time (estimated to be <abbr>UT</abbr>
+00:19:32.13), but the <code><abbr>tz</abbr></code>
code cannot represent the fractional second.
In practice these old specifications were rarely if ever
implemented to subsecond precision.
</li>
<li>
Even when all the timestamp transitions recorded by the
<code><abbr>tz</abbr></code> database are correct, the
<code><abbr>tz</abbr></code> rules that generate them may not
faithfully reflect the historical rules.
For example, from 1922 until World War II the UK moved clocks
forward the day following the third Saturday in April unless that
was Easter, in which case it moved clocks forward the previous
Sunday.
Because the <code><abbr>tz</abbr></code> database has no
way to specify Easter, these exceptional years are entered as
separate <code><abbr>tz</abbr> Rule</code> lines, even though the
legal rules did not change.
When transitions are known but the historical rules behind them are not,
the database contains <code>Zone</code> and <code>Rule</code>
entries that are intended to represent only the generated
transitions, not any underlying historical rules; however, this
intent is recorded at best only in commentary.
</li>
<li>
The <code><abbr>tz</abbr></code> database models time
using the <a
href="https://en.wikipedia.org/wiki/Proleptic_Gregorian_calendar">proleptic
Gregorian calendar</a> with days containing 24 equal-length hours
numbered 00 through 23, except when clock transitions occur.
Pre-standard time is modeled as local mean time.
However, historically many people used other calendars and other timescales.
For example, the Roman Empire used
the <a href="https://en.wikipedia.org/wiki/Julian_calendar">Julian
calendar</a>,
and <a href="https://en.wikipedia.org/wiki/Roman_timekeeping">Roman
timekeeping</a> had twelve varying-length daytime hours with a
non-hour-based system at night.
And even today, some local practices diverge from the Gregorian
calendar with 24-hour days. These divergences range from
relatively minor, such as Japanese bars giving times like "24:30" for the
wee hours of the morning, to more-significant differences such as <a
href="https://www.pri.org/stories/2015-01-30/if-you-have-meeting-ethiopia-you-better-double-check-time">the
east African practice of starting the day at dawn</a>, renumbering
the Western 06:00 to be 12:00. These practices are largely outside
the scope of the <code><abbr>tz</abbr></code> code and data, which
provide only limited support for date and time localization
such as that required by POSIX. If DST is not used a different time zone
can often do the trick; for example, in Kenya a <code>TZ</code> setting
like <code>&lt;-03&gt;3</code> or <code>America/Cayenne</code> starts
the day six hours later than <code>Africa/Nairobi</code> does.
</li>
<li>
Early clocks were less reliable, and data entries do not represent
clock error.
</li>
<li>
The <code><abbr>tz</abbr></code> database assumes Universal Time
(<abbr>UT</abbr>) as an origin, even though <abbr>UT</abbr> is not
standardized for older timestamps.
In the <code><abbr>tz</abbr></code> database commentary,
<abbr>UT</abbr> denotes a family of time standards that includes
Coordinated Universal Time (<abbr>UTC</abbr>) along with other
variants such as <abbr>UT1</abbr> and <abbr>GMT</abbr>,
with days starting at midnight.
Although <abbr>UT</abbr> equals <abbr>UTC</abbr> for modern
timestamps, <abbr>UTC</abbr> was not defined until 1960, so
commentary uses the more-general abbreviation <abbr>UT</abbr> for
timestamps that might predate 1960.
Since <abbr>UT</abbr>, <abbr>UT1</abbr>, etc. disagree slightly,
and since pre-1972 <abbr>UTC</abbr> seconds varied in length,
interpretation of older timestamps can be problematic when
subsecond accuracy is needed.
</li>
<li>
Civil time was not based on atomic time before 1972, and we do not
know the history of
<a href="https://en.wikipedia.org/wiki/Earth's_rotation">earth's
rotation</a> accurately enough to map <a
href="https://en.wikipedia.org/wiki/International_System_of_Units"><abbr
title="International System of Units">SI</abbr></a> seconds to
historical <a href="https://en.wikipedia.org/wiki/Solar_time">solar time</a>
to more than about one-hour accuracy.
See: Stephenson FR, Morrison LV, Hohenkerk CY.
<a href="https://dx.doi.org/10.1098/rspa.2016.0404">Measurement of
the Earth's rotation: 720 BC to AD 2015</a>.
<cite>Proc Royal Soc A</cite>. 2016 Dec 7;472:20160404.
Also see: Espenak F. <a
href="https://eclipse.gsfc.nasa.gov/SEhelp/uncertainty2004.html">Uncertainty
in Delta T (ΔT)</a>.
</li>
<li>
The relationship between POSIX time (that is, <abbr>UTC</abbr> but
ignoring <a href="https://en.wikipedia.org/wiki/Leap_second">leap
seconds</a>) and <abbr>UTC</abbr> is not agreed upon after 1972.
Although the POSIX
clock officially stops during an inserted leap second, at least one
proposed standard has it jumping back a second instead; and in
practice POSIX clocks more typically either progress glacially during
a leap second, or are slightly slowed while near a leap second.
</li>
<li>
The <code><abbr>tz</abbr></code> database does not represent how
uncertain its information is.
Ideally it would contain information about when data entries are
incomplete or dicey.
Partial temporal knowledge is a field of active research, though,
and it is not clear how to apply it here.
</li>
</ul>
<p>
In short, many, perhaps most, of the <code><abbr>tz</abbr></code>
database's pre-1970 and future timestamps are either wrong or
misleading.
Any attempt to pass the
<code><abbr>tz</abbr></code> database off as the definition of time
should be unacceptable to anybody who cares about the facts.
In particular, the <code><abbr>tz</abbr></code> database's
<abbr>LMT</abbr> offsets should not be considered meaningful, and
should not prompt creation of timezones
merely because two locations
differ in <abbr>LMT</abbr> or transitioned to standard time at
different dates.
</p>
</section>
<section>
<h2 id="functions">Time and date functions</h2>
<p>
The <code><abbr>tz</abbr></code> code contains time and date functions
that are upwards compatible with those of POSIX.
Code compatible with this package is already
<a href="tz-link.html#tzdb">part of many platforms</a>, where the
primary use of this package is to update obsolete time-related files.
To do this, you may need to compile the time zone compiler
'<code>zic</code>' supplied with this package instead of using the
system '<code>zic</code>', since the format of <code>zic</code>'s
input is occasionally extended, and a platform may still be shipping
an older <code>zic</code>.
</p>
<h3 id="POSIX">POSIX properties and limitations</h3>
<ul>
<li>
<p>
In POSIX, time display in a process is controlled by the
environment variable <code>TZ</code>.
Unfortunately, the POSIX
<code>TZ</code> string takes a form that is hard to describe and
is error-prone in practice.
Also, POSIX <code>TZ</code> strings cannot deal with daylight
saving time rules not based on the Gregorian calendar (as in
Iran), or with situations where more than two time zone
abbreviations or <abbr>UT</abbr> offsets are used in an area.
</p>
<p>
The POSIX <code>TZ</code> string takes the following form:
</p>
<p>
<var>stdoffset</var>[<var>dst</var>[<var>offset</var>][<code>,</code><var>date</var>[<code>/</code><var>time</var>]<code>,</code><var>date</var>[<code>/</code><var>time</var>]]]
</p>
<p>
where:
</p>
<dl>
<dt><var>std</var> and <var>dst</var></dt><dd>
are 3 or more characters specifying the standard
and daylight saving time (<abbr>DST</abbr>) zone abbreviations.
Starting with POSIX.1-2001, <var>std</var> and <var>dst</var>
may also be in a quoted form like '<code>&lt;+09&gt;</code>';
this allows "<code>+</code>" and "<code>-</code>" in the names.
</dd>
<dt><var>offset</var></dt><dd>
is of the form
'<code>[&plusmn;]<var>hh</var>:[<var>mm</var>[:<var>ss</var>]]</code>'
and specifies the offset west of <abbr>UT</abbr>.
'<var>hh</var>' may be a single digit;
0&le;<var>hh</var>&le;24.
The default <abbr>DST</abbr> offset is one hour ahead of
standard time.
</dd>
<dt><var>date</var>[<code>/</code><var>time</var>]<code>,</code><var>date</var>[<code>/</code><var>time</var>]</dt><dd>
specifies the beginning and end of <abbr>DST</abbr>.
If this is absent, the system supplies its own ruleset
for <abbr>DST</abbr>, and its rules can differ from year to year;
typically <abbr>US</abbr> <abbr>DST</abbr> rules are used.
</dd>
<dt><var>time</var></dt><dd>
takes the form
'<var>hh</var><code>:</code>[<var>mm</var>[<code>:</code><var>ss</var>]]'
and defaults to 02:00.
This is the same format as the offset, except that a
leading '<code>+</code>' or '<code>-</code>' is not allowed.
</dd>
<dt><var>date</var></dt><dd>
takes one of the following forms:
<dl>
<dt>J<var>n</var> (1&le;<var>n</var>&le;365)</dt><dd>
origin-1 day number not counting February 29
</dd>
<dt><var>n</var> (0&le;<var>n</var>&le;365)</dt><dd>
origin-0 day number counting February 29 if present
</dd>
<dt><code>M</code><var>m</var><code>.</code><var>n</var><code>.</code><var>d</var>
(0[Sunday]&le;<var>d</var>&le;6[Saturday], 1&le;<var>n</var>&le;5,
1&le;<var>m</var>&le;12)</dt><dd>
for the <var>d</var>th day of week <var>n</var> of
month <var>m</var> of the year, where week 1 is the first
week in which day <var>d</var> appears, and
'<code>5</code>' stands for the last week in which
day <var>d</var> appears (which may be either the 4th or
5th week).
Typically, this is the only useful form; the <var>n</var>
and <code>J</code><var>n</var> forms are rarely used.
</dd>
</dl>
</dd>
</dl>
<p>
Here is an example POSIX <code>TZ</code> string for New
Zealand after 2007.
It says that standard time (<abbr>NZST</abbr>) is 12 hours ahead
of <abbr>UT</abbr>, and that daylight saving time
(<abbr>NZDT</abbr>) is observed from September's last Sunday at
02:00 until April's first Sunday at 03:00:
</p>
<pre><code>TZ='NZST-12NZDT,M9.5.0,M4.1.0/3'</code></pre>
<p>
This POSIX <code>TZ</code> string is hard to remember, and
mishandles some timestamps before 2008.
With this package you can use this instead:
</p>
<pre><code>TZ='Pacific/Auckland'</code></pre>
</li>
<li>
POSIX does not define the <abbr>DST</abbr> transitions
for <code>TZ</code> values like
"<code>EST5EDT</code>".
Traditionally the current <abbr>US</abbr> <abbr>DST</abbr> rules
were used to interpret such values, but this meant that the
<abbr>US</abbr> <abbr>DST</abbr> rules were compiled into each
program that did time conversion. This meant that when
<abbr>US</abbr> time conversion rules changed (as in the United
States in 1987), all programs that did time conversion had to be
recompiled to ensure proper results.
</li>
<li>
The <code>TZ</code> environment variable is process-global, which
makes it hard to write efficient, thread-safe applications that
need access to multiple timezones.
</li>
<li>
In POSIX, there is no tamper-proof way for a process to learn the
system's best idea of local (wall clock) time.
This is important for applications that an administrator wants
used only at certain times &ndash; without regard to whether the
user has fiddled the
<code>TZ</code> environment variable.
While an administrator can "do everything in <abbr>UT</abbr>" to
get around the problem, doing so is inconvenient and precludes
handling daylight saving time shifts &ndash; as might be required to
limit phone calls to off-peak hours.
</li>
<li>
POSIX provides no convenient and efficient way to determine
the <abbr>UT</abbr> offset and time zone abbreviation of arbitrary
timestamps, particularly for timezones
that do not fit into the POSIX model.
</li>
<li>
- POSIX requires that systems ignore leap seconds.
+ POSIX requires that <code>time_t</code> clock counts exclude leap
+ seconds.
</li>
<li>
The <code><abbr>tz</abbr></code> code attempts to support all the
<code>time_t</code> implementations allowed by POSIX.
The <code>time_t</code> type represents a nonnegative count of seconds
since 1970-01-01 00:00:00 <abbr>UTC</abbr>, ignoring leap seconds.
In practice, <code>time_t</code> is usually a signed 64- or 32-bit
integer; 32-bit signed <code>time_t</code> values stop working after
2038-01-19 03:14:07 <abbr>UTC</abbr>, so new implementations these
days typically use a signed 64-bit integer.
Unsigned 32-bit integers are used on one or two platforms, and 36-bit
and 40-bit integers are also used occasionally.
Although earlier POSIX versions allowed <code>time_t</code> to be a
floating-point type, this was not supported by any practical system,
and POSIX.1-2013 and the <code><abbr>tz</abbr></code> code both
require <code>time_t</code> to be an integer type.
</li>
</ul>
<h3 id="POSIX-extensions">Extensions to POSIX in the
<code><abbr>tz</abbr></code> code</h3>
<ul>
<li>
<p>
The <code>TZ</code> environment variable is used in generating
the name of a file from which time-related information is read
(or is interpreted à la POSIX); <code>TZ</code> is no longer
constrained to be a string containing abbreviations
and numeric data as described <a href="#POSIX">above</a>.
The file's format is <dfn><abbr>TZif</abbr></dfn>,
a timezone information format that contains binary data; see
<a href="https://tools.ietf.org/html/8536">Internet
<abbr>RFC</abbr> 8536</a>.
The daylight saving time rules to be used for a
particular timezone are encoded in the
<abbr>TZif</abbr> file; the format of the file allows <abbr>US</abbr>,
Australian, and other rules to be encoded, and
allows for situations where more than two time zone
abbreviations are used.
</p>
<p>
It was recognized that allowing the <code>TZ</code> environment
variable to take on values such as '<code>America/New_York</code>'
might cause "old" programs (that expect <code>TZ</code> to have a
certain form) to operate incorrectly; consideration was given to using
some other environment variable (for example, <code>TIMEZONE</code>)
to hold the string used to generate the <abbr>TZif</abbr> file's name.
In the end, however, it was decided to continue using
<code>TZ</code>: it is widely used for time zone purposes;
separately maintaining both <code>TZ</code>
and <code>TIMEZONE</code> seemed a nuisance; and systems where
"new" forms of <code>TZ</code> might cause problems can simply
use legacy <code>TZ</code> values such as "<code>EST5EDT</code>" which
can be used by "new" programs as well as by "old" programs that
assume pre-POSIX <code>TZ</code> values.
</p>
</li>
<li>
The code supports platforms with a <abbr>UT</abbr> offset member
in <code>struct tm</code>, e.g., <code>tm_gmtoff</code>.
</li>
<li>
The code supports platforms with a time zone abbreviation member in
<code>struct tm</code>, e.g., <code>tm_zone</code>.
</li>
<li>
Functions <code>tzalloc</code>, <code>tzfree</code>,
<code>localtime_rz</code>, and <code>mktime_z</code> for
more-efficient thread-safe applications that need to use multiple
timezones.
The <code>tzalloc</code> and <code>tzfree</code> functions
allocate and free objects of type <code>timezone_t</code>,
and <code>localtime_rz</code> and <code>mktime_z</code> are
like <code>localtime_r</code> and <code>mktime</code> with an
extra <code>timezone_t</code> argument.
The functions were inspired by <a href="https://netbsd.org/">NetBSD</a>.
</li>
<li>
A function <code>tzsetwall</code> has been added to arrange for the
system's best approximation to local (wall clock) time to be delivered
by subsequent calls to <code>localtime</code>.
Source code for portable applications that "must" run on local
time should call <code>tzsetwall</code>;
if such code is moved to "old" systems that do not
provide <code>tzsetwall</code>, you will not be able to generate an
executable program.
(These functions also arrange for local time to
be used if <code>tzset</code> is called &ndash; directly or
indirectly &ndash; and there is no <code>TZ</code> environment
variable; portable applications should not, however, rely on this
behavior since it is not the way <a
href="https://en.wikipedia.org/wiki/UNIX_System_V#SVR2"><abbr>SVR2</abbr></a>
systems behave.)
</li>
<li>
Negative <code>time_t</code> values are supported, on systems
where <code>time_t</code> is signed.
</li>
<li>
- These functions can account for leap seconds, thanks to Bradley White.
+ These functions can account for leap seconds;
+ see <a href="#leapsec">Leap seconds</a> below.
</li>
</ul>
<h3 id="vestigial">POSIX features no longer needed</h3>
<p>
POSIX and <a href="https://en.wikipedia.org/wiki/ISO_C"><abbr>ISO</abbr> C</a>
define some <a href="https://en.wikipedia.org/wiki/API"><abbr
title="application programming interface">API</abbr>s</a> that are vestigial:
they are not needed, and are relics of a too-simple model that does
not suffice to handle many real-world timestamps.
Although the <code><abbr>tz</abbr></code> code supports these
vestigial <abbr>API</abbr>s for backwards compatibility, they should
be avoided in portable applications.
The vestigial <abbr>API</abbr>s are:
</p>
<ul>
<li>
The POSIX <code>tzname</code> variable does not suffice and is no
longer needed.
To get a timestamp's time zone abbreviation, consult
the <code>tm_zone</code> member if available; otherwise,
use <code>strftime</code>'s <code>"%Z"</code> conversion
specification.
</li>
<li>
The POSIX <code>daylight</code> and <code>timezone</code>
variables do not suffice and are no longer needed.
To get a timestamp's <abbr>UT</abbr> offset, consult
the <code>tm_gmtoff</code> member if available; otherwise,
subtract values returned by <code>localtime</code>
and <code>gmtime</code> using the rules of the Gregorian calendar,
or use <code>strftime</code>'s <code>"%z"</code> conversion
specification if a string like <code>"+0900"</code> suffices.
</li>
<li>
The <code>tm_isdst</code> member is almost never needed and most of
its uses should be discouraged in favor of the abovementioned
<abbr>API</abbr>s.
Although it can still be used in arguments to
<code>mktime</code> to disambiguate timestamps near
a <abbr>DST</abbr> transition when the clock jumps back, this
disambiguation does not work when standard time itself jumps back,
which can occur when a location changes to a time zone with a
lesser <abbr>UT</abbr> offset.
</li>
</ul>
<h3 id="other-portability">Other portability notes</h3>
<ul>
<li>
The <a href="https://en.wikipedia.org/wiki/Version_7_Unix">7th Edition
UNIX</a> <code>timezone</code> function is not present in this
package; it is impossible to reliably map <code>timezone</code>'s
arguments (a "minutes west of <abbr>GMT</abbr>" value and a
"daylight saving time in effect" flag) to a time zone
abbreviation, and we refuse to guess.
Programs that in the past used the <code>timezone</code> function
may now examine <code>localtime(&amp;clock)-&gt;tm_zone</code>
(if <code>TM_ZONE</code> is defined) or
<code>tzname[localtime(&amp;clock)-&gt;tm_isdst]</code>
(if <code>HAVE_TZNAME</code> is defined) to learn the correct time
zone abbreviation to use.
</li>
<li>
The <a
href="https://en.wikipedia.org/wiki/History_of_the_Berkeley_Software_Distribution#4.2BSD"><abbr>4.2BSD</abbr></a>
<code>gettimeofday</code> function is not
used in this package.
This formerly let users obtain the current <abbr>UTC</abbr> offset
and <abbr>DST</abbr> flag, but this functionality was removed in
later versions of <abbr>BSD</abbr>.
</li>
<li>
In <abbr>SVR2</abbr>, time conversion fails for near-minimum or
near-maximum <code>time_t</code> values when doing conversions
for places that do not use <abbr>UT</abbr>.
This package takes care to do these conversions correctly.
A comment in the source code tells how to get compatibly wrong
results.
</li>
<li>
The functions that are conditionally compiled
if <code>STD_INSPIRED</code> is defined should, at this point, be
looked on primarily as food for thought.
They are not in any sense "standard compatible" &ndash; some are
not, in fact, specified in <em>any</em> standard.
They do, however, represent responses of various authors to
standardization proposals.
</li>
<li>
Other time conversion proposals, in particular those supported by the
<a href="https://howardhinnant.github.io/date/tz.html">Time Zone
Database Parser</a>, offer a wider selection of functions
that provide capabilities beyond those provided here.
The absence of such functions from this package is not meant to
discourage the development, standardization, or use of such
functions.
Rather, their absence reflects the decision to make this package
contain valid extensions to POSIX, to ensure its broad
acceptability.
If more powerful time conversion functions can be standardized, so
much the better.
</li>
</ul>
</section>
<section>
<h2 id="stability">Interface stability</h2>
<p>
The <code><abbr>tz</abbr></code> code and data supply the following interfaces:
</p>
<ul>
<li>
A set of timezone names as per
"<a href="#naming">Timezone identifiers</a>" above.
</li>
<li>
Library functions described in "<a href="#functions">Time and date
functions</a>" above.
</li>
<li>
The programs <code>tzselect</code>, <code>zdump</code>,
and <code>zic</code>, documented in their man pages.
</li>
<li>
The format of <code>zic</code> input files, documented in
the <code>zic</code> man page.
</li>
<li>
The format of <code>zic</code> output files, documented in
the <code>tzfile</code> man page.
</li>
<li>
The format of zone table files, documented in <code>zone1970.tab</code>.
</li>
<li>
The format of the country code file, documented in <code>iso3166.tab</code>.
</li>
<li>
The version number of the code and data, as the first line of
the text file '<code>version</code>' in each release.
</li>
</ul>
<p>
Interface changes in a release attempt to preserve compatibility with
recent releases.
For example, <code><abbr>tz</abbr></code> data files typically do not
rely on recently-added <code>zic</code> features, so that users can
run older <code>zic</code> versions to process newer data files.
<a href="tz-link.html#download">Downloading
the <code><abbr>tz</abbr></code> database</a> describes how releases
are tagged and distributed.
</p>
<p>
Interfaces not listed above are less stable.
For example, users should not rely on particular <abbr>UT</abbr>
offsets or abbreviations for timestamps, as data entries are often
based on guesswork and these guesses may be corrected or improved.
</p>
<p>
Timezone boundaries are not part of the stable interface.
For example, even though the <samp>Asia/Bangkok</samp> timezone
currently includes Chang Mai, Hanoi, and Phnom Penh, this is not part
of the stable interface and the timezone can split at any time.
If a calendar application records a future event in some location other
than Bangkok by putting "<samp>Asia/Bangkok</samp>" in the event's record,
the application should be robust in the presence of timezone splits
between now and the future time.
+</p>
+</section>
+
+<section>
+ <h2 id="leapsec">Leap seconds</h2>
+<p>
+The <code><abbr>tz</abbr></code> code and data can account for leap seconds,
+thanks to code contributed by Bradley White.
+However, the leap second support of this package is rarely used directly
+because POSIX requires leap seconds to be excluded and many
+software packages would mishandle leap seconds if they were present.
+Instead, leap seconds are more commonly handled by occasionally adjusting
+the operating system kernel clock as described in
+<a href="tz-link.html#precision">Precision timekeeping</a>,
+and this package by default installs a <samp>leapseconds</samp> file
+commonly used by
+<a href="http://www.ntp.org"><abbr title="Network Time Protocol">NTP</abbr></a>
+software that adjusts the kernel clock.
+However, kernel-clock twiddling approximates UTC only roughly,
+and systems needing more-precise UTC can use this package's leap
+second support directly.
+</p>
+
+<p>
+The directly-supported mechanism assumes that <code>time_t</code>
+counts of seconds since the POSIX epoch normally include leap seconds,
+as opposed to POSIX <code>time_t</code> counts which exclude leap seconds.
+This modified timescale is converted to <abbr>UTC</abbr>
+at the same point that time zone and DST adjustments are applied &ndash;
+namely, at calls to <code>localtime</code> and analogous functions &ndash;
+and the process is driven by leap second information
+stored in alternate versions of the <abbr>TZif</abbr> files.
+Because a leap second adjustment may be needed even
+if no time zone correction is desired,
+calls to <code>gmtime</code>-like functions
+also need to consult a <abbr>TZif</abbr> file,
+conventionally named <samp><abbr>GMT</abbr></samp>,
+to see whether leap second corrections are needed.
+To convert an application's <code>time_t</code> timestamps to or from
+POSIX <code>time_t</code> timestamps (for use when, say,
+embedding or interpreting timestamps in portable
+<a href="https://en.wikipedia.org/wiki/Tar_(computing)"><code>tar</code></a>
+files),
+the application can call the utility functions
+<code>time2posix</code> and <code>posix2time</code>
+included with this package.
+</p>
+
+<p>
+If the POSIX-compatible <abbr>TZif</abbr> file set is installed
+in a directory whose basename is <samp>zoneinfo</samp>, the
+leap-second-aware file set is by default installed in a separate
+directory <samp>zoneinfo-leaps</samp>.
+Although each process can have its own time zone by setting
+its <code>TZ</code> environment variable, there is no support for some
+processes being leap-second aware while other processes are
+POSIX-compatible; the leap-second choice is system-wide.
+So if you configure your kernel to count leap seconds, you should also
+discard <samp>zoneinfo</samp> and rename <samp>zoneinfo-leaps</samp>
+to <samp>zoneinfo</samp>.
+Alternatively, you can install just one set of <abbr>TZif</abbr> files
+in the first place; see the <code>REDO</code> variable in this package's
+<a href="https://en.wikipedia.org/wiki/Makefile">makefile</a>.
</p>
</section>
<section>
<h2 id="calendar">Calendrical issues</h2>
<p>
Calendrical issues are a bit out of scope for a time zone database,
but they indicate the sort of problems that we would run into if we
extended the time zone database further into the past.
An excellent resource in this area is Edward M. Reingold
and Nachum Dershowitz, <cite><a
href="https://www.cambridge.org/fr/academic/subjects/computer-science/computing-general-interest/calendrical-calculations-ultimate-edition-4th-edition">Calendrical
Calculations: The Ultimate Edition</a></cite>, Cambridge University Press (2018).
Other information and sources are given in the file '<code>calendars</code>'
in the <code><abbr>tz</abbr></code> distribution.
They sometimes disagree.
</p>
</section>
<section>
<h2 id="planets">Time and time zones on other planets</h2>
<p>
Some people's work schedules
use <a href="https://en.wikipedia.org/wiki/Timekeeping_on_Mars">Mars time</a>.
Jet Propulsion Laboratory (JPL) coordinators kept Mars time on
and off during the
<a href="https://en.wikipedia.org/wiki/Mars_Pathfinder">Mars
Pathfinder</a> mission.
Some of their family members also adapted to Mars time.
Dozens of special Mars watches were built for JPL workers who kept
Mars time during the Mars Exploration Rovers mission (2004).
These timepieces look like normal Seikos and Citizens but use Mars
seconds rather than terrestrial seconds.
</p>
<p>
A Mars solar day is called a "sol" and has a mean period equal to
about 24 hours 39 minutes 35.244 seconds in terrestrial time.
It is divided into a conventional 24-hour clock, so each Mars second
equals about 1.02749125 terrestrial seconds.
</p>
<p>
The <a href="https://en.wikipedia.org/wiki/Prime_meridian">prime
meridian</a> of Mars goes through the center of the crater
<a href="https://en.wikipedia.org/wiki/Airy-0">Airy-0</a>, named in
honor of the British astronomer who built the Greenwich telescope that
defines Earth's prime meridian.
Mean solar time on the Mars prime meridian is
called Mars Coordinated Time (<abbr>MTC</abbr>).
</p>
<p>
Each landed mission on Mars has adopted a different reference for
solar timekeeping, so there is no real standard for Mars time zones.
For example, the
<a href="https://en.wikipedia.org/wiki/Mars_Exploration_Rover">Mars
Exploration Rover</a> project (2004) defined two time zones "Local
Solar Time A" and "Local Solar Time B" for its two missions, each zone
designed so that its time equals local true solar time at
approximately the middle of the nominal mission.
Such a "time zone" is not particularly suited for any application
other than the mission itself.
</p>
<p>
Many calendars have been proposed for Mars, but none have achieved
wide acceptance.
Astronomers often use Mars Sol Date (<abbr>MSD</abbr>) which is a
sequential count of Mars solar days elapsed since about 1873-12-29
12:00 <abbr>GMT</abbr>.
</p>
<p>
In our solar system, Mars is the planet with time and calendar most
like Earth's.
On other planets, Sun-based time and calendars would work quite
differently.
For example, although Mercury's
<a href="https://en.wikipedia.org/wiki/Rotation_period">sidereal
rotation period</a> is 58.646 Earth days, Mercury revolves around the
Sun so rapidly that an observer on Mercury's equator would see a
sunrise only every 175.97 Earth days, i.e., a Mercury year is 0.5 of a
Mercury day.
Venus is more complicated, partly because its rotation is slightly
<a href="https://en.wikipedia.org/wiki/Retrograde_motion">retrograde</a>:
its year is 1.92 of its days.
Gas giants like Jupiter are trickier still, as their polar and
equatorial regions rotate at different rates, so that the length of a
day depends on latitude.
This effect is most pronounced on Neptune, where the day is about 12
hours at the poles and 18 hours at the equator.
</p>
<p>
Although the <code><abbr>tz</abbr></code> database does not support
time on other planets, it is documented here in the hopes that support
will be added eventually.
</p>
<p>
Sources for time on other planets:
</p>
<ul>
<li>
Michael Allison and Robert Schmunk,
"<a href="https://www.giss.nasa.gov/tools/mars24/help/notes.html">Technical
Notes on Mars Solar Time as Adopted by the Mars24 Sunclock</a>"
(2018-12-13).
</li>
<li>
Jia-Rui Chong,
"<a href="https://www.latimes.com/archives/la-xpm-2004-jan-14-sci-marstime14-story.html">Workdays
Fit for a Martian</a>", <cite>Los Angeles Times</cite>
(2004-01-14), pp A1, A20&ndash;A21.
</li>
<li>
Tom Chmielewski,
"<a href="https://www.theatlantic.com/technology/archive/2015/02/jet-lag-is-worse-on-mars/386033/">Jet
Lag Is Worse on Mars</a>", <cite>The Atlantic</cite> (2015-02-26)
</li>
<li>
Matt Williams,
"<a href="https://www.universetoday.com/37481/days-of-the-planets/">How
long is a day on the other planets of the solar system?</a>"
(2016-01-20).
</li>
</ul>
</section>
<footer>
<hr>
This file is in the public domain, so clarified as of 2009-05-17 by
Arthur David Olson.
</footer>
</body>
</html>
Index: stable/12/contrib/tzdata/version
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