diff --git a/contrib/tzcode/CONTRIBUTING b/contrib/tzcode/CONTRIBUTING index 4c0f56a50265..6d800e4c03a3 100644 --- a/contrib/tzcode/CONTRIBUTING +++ b/contrib/tzcode/CONTRIBUTING @@ -1,97 +1,97 @@ # Contributing to the tz code and data Please do not create issues or pull requests on GitHub, as the proper procedure for proposing and distributing patches is via email as described below. The time zone database is by no means authoritative: governments change timekeeping rules erratically and sometimes with little warning, the data entries do not cover all of civil time before 1970, and undoubtedly errors remain in the code and data. Feel free to fill gaps or fix mistakes, and please email improvements to for use in the future. In your email, please give reliable sources that reviewers can check. ## Contributing technical changes To email small changes, please run a POSIX shell command like 'diff -u old/europe new/europe >myfix.patch', and attach 'myfix.patch' to the email. -For more-elaborate or possibly-controversial changes, +For more-elaborate or possibly controversial changes, such as renaming, adding or removing zones, please read "Theory and pragmatics of the tz code and data" . It is also good to browse the mailing list archives for examples of patches that tend to work well. Additions to data should contain commentary citing reliable sources as justification. Citations should use "https:" URLs if available. For changes that fix sensitive security-related bugs, please see the distribution's 'SECURITY' file. Please submit changes against either the latest release or the main branch of the development repository. The latter is preferred. ## Sample Git workflow for developing contributions If you use Git the following workflow may be helpful: * Copy the development repository. git clone https://github.com/eggert/tz.git cd tz * Get current with the main branch. git checkout main git pull * Switch to a new branch for the changes. Choose a different branch name for each change set. git checkout -b mybranch * Sleuth by using 'git blame'. For example, when fixing data for Africa/Sao_Tome, if the command 'git blame africa' outputs a line '2951fa3b (Paul Eggert 2018-01-08 09:03:13 -0800 1068) Zone Africa/Sao_Tome 0:26:56 - LMT 1884', commit 2951fa3b should provide some justification for the 'Zone Africa/Sao_Tome' line. * Edit source files. Include commentary that justifies the changes by citing reliable sources. * Debug the changes, e.g.: make check make install ./zdump -v America/Los_Angeles * For each separable change, commit it in the new branch, e.g.: git add northamerica git commit See recent 'git log' output for the commit-message style. * Create patch files 0001-..., 0002-..., ... git format-patch main * After reviewing the patch files, send the patches to for others to review. git send-email main For an archived example of such an email, see "[PROPOSED] Fix off-by-1 error for Jamaica and T&C before 1913" . * Start anew by getting current with the main branch again (the second step above). ----- This file is in the public domain. diff --git a/contrib/tzcode/Makefile b/contrib/tzcode/Makefile index afb9d538a203..0e56af89e2a4 100644 --- a/contrib/tzcode/Makefile +++ b/contrib/tzcode/Makefile @@ -1,1250 +1,1250 @@ # Make and install tzdb code and data. # This file is in the public domain, so clarified as of # 2009-05-17 by Arthur David Olson. # Package name for the code distribution. PACKAGE= tzcode # Version number for the distribution, overridden in the 'tarballs' rule below. VERSION= unknown # Email address for bug reports. BUGEMAIL= tz@iana.org # DATAFORM selects the data format. # Available formats represent essentially the same data, albeit # possibly with minor discrepancies that users are not likely to notice. # To get new features and the best data right away, use: # DATAFORM= vanguard # To wait a while before using new features, to give downstream users # time to upgrade zic (the default), use: # DATAFORM= main # To wait even longer for new features, use: # DATAFORM= rearguard # Rearguard users might also want "ZFLAGS = -b fat"; see below. DATAFORM= main # Change the line below for your timezone (after finding the one you want in # one of the $(TDATA) source files, or adding it to a source file). # Alternatively, if you discover you've got the wrong timezone, you can just # 'zic -l -' to remove it, or 'zic -l rightzone' to change it. # Use the command # make zonenames # to get a list of the values you can use for LOCALTIME. LOCALTIME= Factory -# The POSIXRULES macro controls interpretation of nonstandard and obsolete -# POSIX-like TZ settings like TZ='EET-2EEST' that lack DST transition rules. -# Such a setting uses the rules in a template file to determine -# "spring forward" and "fall back" days and times; the environment -# variable itself specifies UT offsets of standard and daylight saving time. -# +# The POSIXRULES macro controls interpretation of POSIX-like TZ +# settings like TZ='EET-2EEST' that lack DST transition rules. # If POSIXRULES is '-', no template is installed; this is the default. -# # Any other value for POSIXRULES is obsolete and should not be relied on, as: # * It does not work correctly in popular implementations such as GNU/Linux. # * It does not work even in tzcode, except for historical timestamps # that precede the last explicit transition in the POSIXRULES file. # Hence it typically does not work for current and future timestamps. -# In short, software should avoid ruleless settings like TZ='EET-2EEST' -# and so should not depend on the value of POSIXRULES. -# # If, despite the above, you want a template for handling these settings, # you can change the line below (after finding the timezone you want in the # one of the $(TDATA) source files, or adding it to a source file). # Alternatively, if you discover you've got the wrong timezone, you can just # 'zic -p -' to remove it, or 'zic -p rightzone' to change it. # Use the command # make zonenames # to get a list of the values you can use for POSIXRULES. POSIXRULES= - # Also see TZDEFRULESTRING below, which takes effect only -# if the time zone files cannot be accessed. +# if POSIXRULES is '-' or if the template file cannot be accessed. # Installation locations. # # The defaults are suitable for Debian, except that if REDO is # posix_right or right_posix then files that Debian puts under # /usr/share/zoneinfo/posix and /usr/share/zoneinfo/right are instead # put under /usr/share/zoneinfo-posix and /usr/share/zoneinfo-leaps, # respectively. Problems with the Debian approach are discussed in # the commentary for the right_posix rule (below). # Destination directory, which can be used for staging. # 'make DESTDIR=/stage install' installs under /stage (e.g., to # /stage/etc/localtime instead of to /etc/localtime). Files under # /stage are not intended to work as-is, but can be copied by hand to # the root directory later. If DESTDIR is empty, 'make install' does # not stage, but installs directly into production locations. DESTDIR = # Everything is installed into subdirectories of TOPDIR, and used there. # TOPDIR should be empty (meaning the root directory), # or a directory name that does not end in "/". # TOPDIR should be empty or an absolute name unless you're just testing. TOPDIR = # The default local timezone is taken from the file TZDEFAULT. TZDEFAULT = $(TOPDIR)/etc/localtime # The subdirectory containing installed program and data files, and # likewise for installed files that can be shared among architectures. # These should be relative file names. USRDIR = usr USRSHAREDIR = $(USRDIR)/share # "Compiled" timezone information is placed in the "TZDIR" directory # (and subdirectories). # TZDIR_BASENAME should not contain "/" and should not be ".", ".." or empty. TZDIR_BASENAME= zoneinfo TZDIR = $(TOPDIR)/$(USRSHAREDIR)/$(TZDIR_BASENAME) # The "tzselect" and (if you do "make INSTALL") "date" commands go in: BINDIR = $(TOPDIR)/$(USRDIR)/bin # The "zdump" command goes in: ZDUMPDIR = $(BINDIR) # The "zic" command goes in: ZICDIR = $(TOPDIR)/$(USRDIR)/sbin # Manual pages go in subdirectories of. . . MANDIR = $(TOPDIR)/$(USRSHAREDIR)/man # Library functions are put in an archive in LIBDIR. LIBDIR = $(TOPDIR)/$(USRDIR)/lib # Types to try, as an alternative to time_t. TIME_T_ALTERNATIVES = $(TIME_T_ALTERNATIVES_HEAD) $(TIME_T_ALTERNATIVES_TAIL) TIME_T_ALTERNATIVES_HEAD = int_least64_t TIME_T_ALTERNATIVES_TAIL = int_least32_t uint_least32_t uint_least64_t # What kind of TZif data files to generate. (TZif is the binary time # zone data format that zic generates; see Internet RFC 8536.) # If you want only POSIX time, with time values interpreted as # seconds since the epoch (not counting leap seconds), use # REDO= posix_only # below. If you want only "right" time, with values interpreted # as seconds since the epoch (counting leap seconds), use # REDO= right_only # below. If you want both sets of data available, with leap seconds not # counted normally, use # REDO= posix_right # below. If you want both sets of data available, with leap seconds counted # normally, use # REDO= right_posix # below. POSIX mandates that leap seconds not be counted; for compatibility # with it, use "posix_only" or "posix_right". Use POSIX time on systems with # leap smearing; this can work better than unsmeared "right" time with # applications that are not leap second aware, and is closer to unsmeared # "right" time than unsmeared POSIX time is (e.g., 0.5 vs 1.0 s max error). REDO= posix_right # Whether to put an "Expires" line in the leapseconds file. # Use EXPIRES_LINE=1 to put the line in, 0 to omit it. # The EXPIRES_LINE value matters only if REDO's value contains "right". # If you change EXPIRES_LINE, remove the leapseconds file before running "make". # zic's support for the Expires line was introduced in tzdb 2020a, # and was modified in tzdb 2021b to generate version 4 TZif files. # EXPIRES_LINE defaults to 0 for now so that the leapseconds file # can be given to pre-2020a zic implementations and so that TZif files # built by newer zic implementations can be read by pre-2021b libraries. EXPIRES_LINE= 0 # To install data in text form that has all the information of the TZif data, # (optionally incorporating leap second information), use # TZDATA_TEXT= tzdata.zi leapseconds # To install text data without leap second information (e.g., because # REDO='posix_only'), use # TZDATA_TEXT= tzdata.zi # To avoid installing text data, use # TZDATA_TEXT= TZDATA_TEXT= leapseconds tzdata.zi # For backward-compatibility links for old zone names, use # BACKWARD= backward # To omit these links, use # BACKWARD= BACKWARD= backward # If you want out-of-scope and often-wrong data from the file 'backzone', # but only for entries listed in the backward-compatibility file zone.tab, use # PACKRATDATA= backzone # PACKRATLIST= zone.tab # If you want all the 'backzone' data, use # PACKRATDATA= backzone # PACKRATLIST= # To omit this data, use # PACKRATDATA= # PACKRATLIST= PACKRATDATA= PACKRATLIST= # The name of a locale using the UTF-8 encoding, used during self-tests. # The tests are skipped if the name does not appear to work on this system. UTF8_LOCALE= en_US.utf8 # Non-default libraries needed to link. # On some hosts, this should have -lintl unless CFLAGS has -DHAVE_GETTEXT=0. LDLIBS= # Add the following to the end of the "CFLAGS=" line as needed to override # defaults specified in the source code. "-DFOO" is equivalent to "-DFOO=1". # -DDEPRECATE_TWO_DIGIT_YEARS for optional runtime warnings about strftime # formats that generate only the last two digits of year numbers # -DEPOCH_LOCAL if the 'time' function returns local time not UT # -DEPOCH_OFFSET=N if the 'time' function returns a value N greater # than what POSIX specifies, assuming local time is UT. # For example, N is 252460800 on AmigaOS. # -DHAVE_DECL_ASCTIME_R=0 if does not declare asctime_r # -DHAVE_DECL_ENVIRON if declares 'environ' # -DHAVE_DECL_TIMEGM=0 if does not declare timegm # -DHAVE_DIRECT_H if mkdir needs (MS-Windows) -# -DHAVE_GENERIC=0 if _Generic does not work* +# -DHAVE__GENERIC=0 if _Generic does not work* # -DHAVE_GETRANDOM if getrandom works (e.g., GNU/Linux), # -DHAVE_GETRANDOM=0 to avoid using getrandom # -DHAVE_GETTEXT if gettext works (e.g., GNU/Linux, FreeBSD, Solaris), # where LDLIBS also needs to contain -lintl on some hosts; # -DHAVE_GETTEXT=0 to avoid using gettext # -DHAVE_INCOMPATIBLE_CTIME_R if your system's time.h declares # ctime_r and asctime_r incompatibly with the POSIX standard # (Solaris when _POSIX_PTHREAD_SEMANTICS is not defined). -# -DHAVE_INTTYPES_H=0 if does not work* +# -DHAVE_INTTYPES_H=0 if does not work*+ # -DHAVE_LINK=0 if your system lacks a link function # -DHAVE_LOCALTIME_R=0 if your system lacks a localtime_r function # -DHAVE_LOCALTIME_RZ=0 if you do not want zdump to use localtime_rz # localtime_rz can make zdump significantly faster, but is nonstandard. # -DHAVE_MALLOC_ERRNO=0 if malloc etc. do not set errno on failure. # -DHAVE_POSIX_DECLS=0 if your system's include files do not declare # functions like 'link' or variables like 'tzname' required by POSIX # -DHAVE_SETENV=0 if your system lacks the setenv function -# -DHAVE_SNPRINTF=0 if your system lacks the snprintf function +# -DHAVE_SNPRINTF=0 if your system lacks the snprintf function+ # -DHAVE_STDCKDINT_H=0 if neither nor substitutes like # __builtin_add_overflow work* -# -DHAVE_STDINT_H=0 if does not work* +# -DHAVE_STDINT_H=0 if does not work*+ # -DHAVE_STRFTIME_L if declares locale_t and strftime_l # -DHAVE_STRDUP=0 if your system lacks the strdup function -# -DHAVE_STRTOLL=0 if your system lacks the strtoll function +# -DHAVE_STRTOLL=0 if your system lacks the strtoll function+ # -DHAVE_SYMLINK=0 if your system lacks the symlink function # -DHAVE_SYS_STAT_H=0 if does not work* # -DHAVE_TZSET=0 if your system lacks a tzset function # -DHAVE_UNISTD_H=0 if does not work* # -DHAVE_UTMPX_H=0 if does not work* # -Dlocale_t=XXX if your system uses XXX instead of locale_t +# -DPORT_TO_C89 if tzcode should also run on C89 platforms+ # -DRESERVE_STD_EXT_IDS if your platform reserves standard identifiers # with external linkage, e.g., applications cannot define 'localtime'. # -Dssize_t=long on hosts like MS-Windows that lack ssize_t +# -DSUPPORT_C89 if the tzcode library should support C89 callers+ # -DSUPPRESS_TZDIR to not prepend TZDIR to file names; this has # security implications and is not recommended for general use # -DTHREAD_SAFE to make localtime.c thread-safe, as POSIX requires; # not needed by the main-program tz code, which is single-threaded. # Append other compiler flags as needed, e.g., -pthread on GNU/Linux. # -Dtime_tz=\"T\" to use T as the time_t type, rather than the system time_t # This is intended for internal use only; it mangles external names. # -DTZ_DOMAIN=\"foo\" to use "foo" for gettext domain name; default is "tz" # -DTZ_DOMAINDIR=\"/path\" to use "/path" for gettext directory; # the default is system-supplied, typically "/usr/lib/locale" # -DTZDEFRULESTRING=\",date/time,date/time\" to default to the specified -# DST transitions if the time zone files cannot be accessed +# DST transitions for POSIX-style TZ strings lacking them, +# in the usual case where POSIXRULES is '-'. If not specified, +# TZDEFRULESTRING defaults to US rules for future DST transitions. +# This mishandles some past timestamps, as US DST rules have changed. +# It also mishandles settings like TZ='EET-2EEST' for eastern Europe, +# as Europe and US DST rules differ. +# -DTZNAME_MAXIMUM=N to limit time zone abbreviations to N bytes (default 255) # -DUNINIT_TRAP if reading uninitialized storage can cause problems # other than simply getting garbage data # -DUSE_LTZ=0 to build zdump with the system time zone library # Also set TZDOBJS=zdump.o and CHECK_TIME_T_ALTERNATIVES= below. # -DZIC_BLOAT_DEFAULT=\"fat\" to default zic's -b option to "fat", and # similarly for "slim". Fat TZif files work around incompatibilities # and bugs in some TZif readers, notably older ones that # ignore or otherwise mishandle 64-bit data in TZif files; # however, fat TZif files may trigger bugs in newer TZif readers. # Slim TZif files are more efficient, and are the default. # -DZIC_MAX_ABBR_LEN_WO_WARN=3 # (or some other number) to set the maximum time zone abbreviation length # that zic will accept without a warning (the default is 6) # $(GCC_DEBUG_FLAGS) if you are using recent GCC and want lots of checking # # * Options marked "*" can be omitted if your compiler is C23 compatible. +# * Options marked "+" are obsolescent and are planned to be removed +# once the code assumes C99 or later. # # Select instrumentation via "make GCC_INSTRUMENT='whatever'". GCC_INSTRUMENT = \ -fsanitize=undefined -fsanitize-address-use-after-scope \ -fsanitize-undefined-trap-on-error -fstack-protector # Omit -fanalyzer from GCC_DEBUG_FLAGS, as it makes GCC too slow. GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \ $(GCC_INSTRUMENT) \ -Wall -Wextra \ -Walloc-size-larger-than=100000 -Warray-bounds=2 \ -Wbad-function-cast -Wbidi-chars=any,ucn -Wcast-align=strict -Wdate-time \ -Wdeclaration-after-statement -Wdouble-promotion \ -Wduplicated-branches -Wduplicated-cond \ -Wformat=2 -Wformat-overflow=2 -Wformat-signedness -Wformat-truncation \ -Wimplicit-fallthrough=5 -Winit-self -Wlogical-op \ -Wmissing-declarations -Wmissing-prototypes -Wnested-externs \ -Wnull-dereference \ -Wold-style-definition -Woverlength-strings -Wpointer-arith \ -Wshadow -Wshift-overflow=2 -Wstrict-overflow \ -Wstrict-prototypes -Wstringop-overflow=4 \ -Wstringop-truncation -Wsuggest-attribute=cold \ -Wsuggest-attribute=const -Wsuggest-attribute=format \ -Wsuggest-attribute=malloc \ -Wsuggest-attribute=noreturn -Wsuggest-attribute=pure \ -Wtrampolines -Wundef -Wuninitialized -Wunused-macros -Wuse-after-free=3 \ -Wvariadic-macros -Wvla -Wwrite-strings \ -Wno-address -Wno-format-nonliteral -Wno-sign-compare \ -Wno-type-limits # # If your system has a "GMT offset" field in its "struct tm"s # (or if you decide to add such a field in your system's "time.h" file), # add the name to a define such as # -DTM_GMTOFF=tm_gmtoff # to the end of the "CFLAGS=" line. If not defined, the code attempts to # guess TM_GMTOFF from other macros; define NO_TM_GMTOFF to suppress this. # Similarly, if your system has a "zone abbreviation" field, define # -DTM_ZONE=tm_zone # and define NO_TM_ZONE to suppress any guessing. Although these two fields # not required by POSIX, a future version of POSIX is planned to require them # and they are widely available on GNU/Linux and BSD systems. # # The next batch of options control support for external variables # exported by tzcode. In practice these variables are less useful # than TM_GMTOFF and TM_ZONE. However, most of them are standardized. # # # # To omit or support the external variable "tzname", add one of: # # -DHAVE_TZNAME=0 # do not support "tzname" # # -DHAVE_TZNAME=1 # support "tzname", which is defined by system library # # -DHAVE_TZNAME=2 # support and define "tzname" # # to the "CFLAGS=" line. "tzname" is required by POSIX 1988 and later. # # If not defined, the code attempts to guess HAVE_TZNAME from other macros. # # Warning: unless time_tz is also defined, HAVE_TZNAME=1 can cause # # crashes when combined with some platforms' standard libraries, # # presumably due to memory allocation issues. # # # # To omit or support the external variables "timezone" and "daylight", add # # -DUSG_COMPAT=0 # do not support # # -DUSG_COMPAT=1 # support, and variables are defined by system library # # -DUSG_COMPAT=2 # support and define variables # # to the "CFLAGS=" line; "timezone" and "daylight" are inspired by # # Unix Systems Group code and are required by POSIX 2008 (with XSI) and later. # # If not defined, the code attempts to guess USG_COMPAT from other macros. # # # # To support the external variable "altzone", add # # -DALTZONE=0 # do not support # # -DALTZONE=1 # support "altzone", which is defined by system library # # -DALTZONE=2 # support and define "altzone" # # to the end of the "CFLAGS=" line; although "altzone" appeared in # # System V Release 3.1 it has not been standardized. # # If not defined, the code attempts to guess ALTZONE from other macros. # # If you want functions that were inspired by early versions of X3J11's work, # add # -DSTD_INSPIRED # to the end of the "CFLAGS=" line. This arranges for the following # functions to be added to the time conversion library. # "offtime" is like "gmtime" except that it accepts a second (long) argument # that gives an offset to add to the time_t when converting it. +# "offtime_r" is to "offtime" what "gmtime_r" is to "gmtime". # "timelocal" is equivalent to "mktime". # "timeoff" is like "timegm" except that it accepts a second (long) argument # that gives an offset to use when converting to a time_t. # "posix2time" and "time2posix" are described in an included manual page. # X3J11's work does not describe any of these functions. # These functions may well disappear in future releases of the time # conversion package. # # If you don't want functions that were inspired by NetBSD, add # -DNETBSD_INSPIRED=0 # to the end of the "CFLAGS=" line. Otherwise, the functions # "localtime_rz", "mktime_z", "tzalloc", and "tzfree" are added to the -# time library, and if STD_INSPIRED is also defined the functions +# time library, and if STD_INSPIRED is also defined to nonzero the functions # "posix2time_z" and "time2posix_z" are added as well. # The functions ending in "_z" (or "_rz") are like their unsuffixed # (or suffixed-by-"_r") counterparts, except with an extra first # argument of opaque type timezone_t that specifies the timezone. # "tzalloc" allocates a timezone_t value, and "tzfree" frees it. # # If you want to allocate state structures in localtime, add # -DALL_STATE # to the end of the "CFLAGS=" line. Storage is obtained by calling malloc. # # NIST-PCTS:151-2, Version 1.4, (1993-12-03) is a test suite put # out by the National Institute of Standards and Technology # which claims to test C and Posix conformance. If you want to pass PCTS, add # -DPCTS # to the end of the "CFLAGS=" line. # # If you want strict compliance with XPG4 as of 1994-04-09, add # -DXPG4_1994_04_09 # to the end of the "CFLAGS=" line. This causes "strftime" to always return # 53 as a week number (rather than 52 or 53) for January days before # January's first Monday when a "%V" format is used and January 1 # falls on a Friday, Saturday, or Sunday. CFLAGS= # Linker flags. Default to $(LFLAGS) for backwards compatibility # to release 2012h and earlier. LDFLAGS= $(LFLAGS) # For leap seconds, this Makefile uses LEAPSECONDS='-L leapseconds' in # submake command lines. The default is no leap seconds. LEAPSECONDS= # The zic command and its arguments. zic= ./zic ZIC= $(zic) $(ZFLAGS) # To shrink the size of installed TZif files, # append "-r @N" to omit data before N-seconds-after-the-Epoch. # To grow the files and work around bugs in older applications, # possibly at the expense of introducing bugs in newer ones, # append "-b fat"; see ZIC_BLOAT_DEFAULT above. # See the zic man page for more about -b and -r. ZFLAGS= # How to use zic to install TZif files. ZIC_INSTALL= $(ZIC) -d '$(DESTDIR)$(TZDIR)' $(LEAPSECONDS) # The name of a Posix-compliant 'awk' on your system. # mawk 1.3.3 and Solaris 10 /usr/bin/awk do not work. # Also, it is better (though not essential) if 'awk' supports UTF-8, # and unfortunately mawk and busybox awk do not support UTF-8. # Try AWK=gawk or AWK=nawk if your awk has the abovementioned problems. AWK= awk # The full path name of a Posix-compliant shell, preferably one that supports # the Korn shell's 'select' statement as an extension. # These days, Bash is the most popular. # It should be OK to set this to /bin/sh, on platforms where /bin/sh # lacks 'select' or doesn't completely conform to Posix, but /bin/bash # is typically nicer if it works. KSHELL= /bin/bash # Name of curl , used for HTML validation. CURL= curl # Name of GNU Privacy Guard , used to sign distributions. GPG= gpg # This expensive test requires USE_LTZ. # To suppress it, define this macro to be empty. CHECK_TIME_T_ALTERNATIVES = check_time_t_alternatives # SAFE_CHAR is a regular expression that matches a safe character. # Some parts of this distribution are limited to safe characters; # others can use any UTF-8 character. # For now, the safe characters are a safe subset of ASCII. # The caller must set the shell variable 'sharp' to the character '#', # since Makefile macros cannot contain '#'. # TAB_CHAR is a single tab character, in single quotes. TAB_CHAR= ' ' SAFE_CHARSET1= $(TAB_CHAR)' !\"'$$sharp'$$%&'\''()*+,./0123456789:;<=>?@' SAFE_CHARSET2= 'ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\^_`' SAFE_CHARSET3= 'abcdefghijklmnopqrstuvwxyz{|}~' SAFE_CHARSET= $(SAFE_CHARSET1)$(SAFE_CHARSET2)$(SAFE_CHARSET3) SAFE_CHAR= '[]'$(SAFE_CHARSET)'-]' -# These characters are Latin-1, and so are likely to be displayable -# even in editors with limited character sets. -UNUSUAL_OK_LATIN_1 = «°±»½¾× -# This IPA symbol is represented in Unicode as the composition of -# U+0075 and U+032F, and U+032F is not considered alphabetic by some -# grep implementations that do not grok composition. -UNUSUAL_OK_IPA = u̯ +# These non-alphabetic, non-ASCII printable characters are Latin-1, +# and so are likely displayable even in editors like XEmacs 21 +# that have limited display capabilities. +UNUSUAL_OK_LATIN_1 = ¡¢£¤¥¦§¨©«¬®¯°±²³´¶·¸¹»¼½¾¿×÷ # Non-ASCII non-letters that OK_CHAR allows, as these characters are # useful in commentary. -UNUSUAL_OK_CHARSET= $(UNUSUAL_OK_LATIN_1)$(UNUSUAL_OK_IPA) +UNUSUAL_OK_CHARSET= $(UNUSUAL_OK_LATIN_1) # Put this in a bracket expression to match spaces. s = [:space:] # OK_CHAR matches any character allowed in the distributed files. # This is the same as SAFE_CHAR, except that UNUSUAL_OK_CHARSET and # multibyte letters are also allowed so that commentary can contain a # few safe symbols and people's names and can quote non-English sources. # Other non-letters are limited to ASCII renderings for the # convenience of maintainers using XEmacs 21.5.34, which by default # mishandles Unicode characters U+0100 and greater. OK_CHAR= '[][:alpha:]$(UNUSUAL_OK_CHARSET)'$(SAFE_CHARSET)'-]' # SAFE_LINE matches a line of safe characters. # SAFE_SHARP_LINE is similar, except any OK character can follow '#'; # this is so that comments can contain non-ASCII characters. # OK_LINE matches a line of OK characters. SAFE_LINE= '^'$(SAFE_CHAR)'*$$' SAFE_SHARP_LINE='^'$(SAFE_CHAR)'*('$$sharp$(OK_CHAR)'*)?$$' OK_LINE= '^'$(OK_CHAR)'*$$' # Flags to give 'tar' when making a distribution. # Try to use flags appropriate for GNU tar. GNUTARFLAGS= --format=pax --pax-option='delete=atime,delete=ctime' \ --numeric-owner --owner=0 --group=0 \ --mode=go+u,go-w --sort=name TARFLAGS= `if tar $(GNUTARFLAGS) --version >/dev/null 2>&1; \ then echo $(GNUTARFLAGS); \ else :; \ fi` # Flags to give 'gzip' when making a distribution. GZIPFLAGS= -9n # When comparing .tzs files, use GNU diff's -F'^TZ=' option if supported. # This makes it easier to see which Zone has been affected. DIFF_TZS= diff -u$$(! diff -u -F'^TZ=' - - <>/dev/null >&0 2>&1 \ || echo ' -F^TZ=') ############################################################################### #MAKE= make cc= cc CC= $(cc) -DTZDIR='"$(TZDIR)"' AR= ar # ':' on typical hosts; 'ranlib' on the ancient hosts that still need ranlib. RANLIB= : TZCOBJS= zic.o TZDOBJS= zdump.o localtime.o asctime.o strftime.o DATEOBJS= date.o localtime.o strftime.o asctime.o LIBSRCS= localtime.c asctime.c difftime.c strftime.c LIBOBJS= localtime.o asctime.o difftime.o strftime.o HEADERS= tzfile.h private.h NONLIBSRCS= zic.c zdump.c NEWUCBSRCS= date.c SOURCES= $(HEADERS) $(LIBSRCS) $(NONLIBSRCS) $(NEWUCBSRCS) \ tzselect.ksh workman.sh MANS= newctime.3 newstrftime.3 newtzset.3 time2posix.3 \ tzfile.5 tzselect.8 zic.8 zdump.8 MANTXTS= newctime.3.txt newstrftime.3.txt newtzset.3.txt \ time2posix.3.txt \ tzfile.5.txt tzselect.8.txt zic.8.txt zdump.8.txt \ date.1.txt COMMON= calendars CONTRIBUTING LICENSE Makefile \ NEWS README SECURITY theory.html version WEB_PAGES= tz-art.html tz-how-to.html tz-link.html CHECK_WEB_PAGES=check_theory.html check_tz-art.html \ check_tz-how-to.html check_tz-link.html DOCS= $(MANS) date.1 $(MANTXTS) $(WEB_PAGES) PRIMARY_YDATA= africa antarctica asia australasia \ europe northamerica southamerica YDATA= $(PRIMARY_YDATA) etcetera NDATA= factory TDATA_TO_CHECK= $(YDATA) $(NDATA) backward TDATA= $(YDATA) $(NDATA) $(BACKWARD) ZONETABLES= zone1970.tab zone.tab TABDATA= iso3166.tab $(TZDATA_TEXT) $(ZONETABLES) LEAP_DEPS= leapseconds.awk leap-seconds.list TZDATA_ZI_DEPS= ziguard.awk zishrink.awk version $(TDATA) \ $(PACKRATDATA) $(PACKRATLIST) DSTDATA_ZI_DEPS= ziguard.awk $(TDATA) $(PACKRATDATA) $(PACKRATLIST) DATA= $(TDATA_TO_CHECK) backzone iso3166.tab leap-seconds.list \ leapseconds $(ZONETABLES) AWK_SCRIPTS= checklinks.awk checktab.awk leapseconds.awk \ ziguard.awk zishrink.awk MISC= $(AWK_SCRIPTS) TZS_YEAR= 2050 TZS_CUTOFF_FLAG= -c $(TZS_YEAR) TZS= to$(TZS_YEAR).tzs TZS_NEW= to$(TZS_YEAR)new.tzs TZS_DEPS= $(YDATA) asctime.c localtime.c \ private.h tzfile.h zdump.c zic.c TZDATA_DIST = $(COMMON) $(DATA) $(MISC) # EIGHT_YARDS is just a yard short of the whole ENCHILADA. EIGHT_YARDS = $(TZDATA_DIST) $(DOCS) $(SOURCES) tzdata.zi ENCHILADA = $(EIGHT_YARDS) $(TZS) # Consult these files when deciding whether to rebuild the 'version' file. # This list is not the same as the output of 'git ls-files', since # .gitignore is not distributed. VERSION_DEPS= \ calendars CONTRIBUTING LICENSE Makefile NEWS README SECURITY \ africa antarctica asctime.c asia australasia \ backward backzone \ checklinks.awk checktab.awk \ date.1 date.c difftime.c \ etcetera europe factory iso3166.tab \ leap-seconds.list leapseconds.awk localtime.c \ newctime.3 newstrftime.3 newtzset.3 northamerica \ private.h southamerica strftime.c theory.html \ time2posix.3 tz-art.html tz-how-to.html tz-link.html \ tzfile.5 tzfile.h tzselect.8 tzselect.ksh \ workman.sh zdump.8 zdump.c zic.8 zic.c \ ziguard.awk zishrink.awk \ zone.tab zone1970.tab # And for the benefit of csh users on systems that assume the user # shell should be used to handle commands in Makefiles. . . SHELL= /bin/sh all: tzselect zic zdump libtz.a $(TABDATA) \ vanguard.zi main.zi rearguard.zi ALL: all date $(ENCHILADA) install: all $(DATA) $(REDO) $(MANS) mkdir -p '$(DESTDIR)$(BINDIR)' \ '$(DESTDIR)$(ZDUMPDIR)' '$(DESTDIR)$(ZICDIR)' \ '$(DESTDIR)$(LIBDIR)' \ '$(DESTDIR)$(MANDIR)/man3' '$(DESTDIR)$(MANDIR)/man5' \ '$(DESTDIR)$(MANDIR)/man8' $(ZIC_INSTALL) -l $(LOCALTIME) \ `case '$(POSIXRULES)' in ?*) echo '-p';; esac \ ` $(POSIXRULES) \ -t '$(DESTDIR)$(TZDEFAULT)' cp -f $(TABDATA) '$(DESTDIR)$(TZDIR)/.' cp tzselect '$(DESTDIR)$(BINDIR)/.' cp zdump '$(DESTDIR)$(ZDUMPDIR)/.' cp zic '$(DESTDIR)$(ZICDIR)/.' cp libtz.a '$(DESTDIR)$(LIBDIR)/.' $(RANLIB) '$(DESTDIR)$(LIBDIR)/libtz.a' cp -f newctime.3 newtzset.3 '$(DESTDIR)$(MANDIR)/man3/.' cp -f tzfile.5 '$(DESTDIR)$(MANDIR)/man5/.' cp -f tzselect.8 zdump.8 zic.8 '$(DESTDIR)$(MANDIR)/man8/.' INSTALL: ALL install date.1 mkdir -p '$(DESTDIR)$(BINDIR)' '$(DESTDIR)$(MANDIR)/man1' cp date '$(DESTDIR)$(BINDIR)/.' cp -f date.1 '$(DESTDIR)$(MANDIR)/man1/.' # Calculate version number from git, if available. # Otherwise, use $(VERSION) unless it is "unknown" and there is already # a 'version' file, in which case reuse the existing 'version' contents # and append "-dirty" if the contents do not already end in "-dirty". version: $(VERSION_DEPS) { (type git) >/dev/null 2>&1 && \ V=`git describe --match '[0-9][0-9][0-9][0-9][a-z]*' \ --abbrev=7 --dirty` || \ if test '$(VERSION)' = unknown && V=`cat $@`; then \ case $$V in *-dirty);; *) V=$$V-dirty;; esac; \ else \ V='$(VERSION)'; \ fi; } && \ printf '%s\n' "$$V" >$@.out mv $@.out $@ # These files can be tailored by setting BACKWARD, PACKRATDATA, PACKRATLIST. vanguard.zi main.zi rearguard.zi: $(DSTDATA_ZI_DEPS) $(AWK) \ -v DATAFORM=`expr $@ : '\(.*\).zi'` \ -v PACKRATDATA='$(PACKRATDATA)' \ -v PACKRATLIST='$(PACKRATLIST)' \ -f ziguard.awk \ $(TDATA) $(PACKRATDATA) >$@.out mv $@.out $@ # This file has a version comment that attempts to capture any tailoring # via BACKWARD, DATAFORM, PACKRATDATA, PACKRATLIST, and REDO. tzdata.zi: $(DATAFORM).zi version zishrink.awk version=`sed 1q version` && \ LC_ALL=C $(AWK) \ -v dataform='$(DATAFORM)' \ -v deps='$(DSTDATA_ZI_DEPS) zishrink.awk' \ -v redo='$(REDO)' \ -v version="$$version" \ -f zishrink.awk \ $(DATAFORM).zi >$@.out mv $@.out $@ version.h: version VERSION=`cat version` && printf '%s\n' \ 'static char const PKGVERSION[]="($(PACKAGE)) ";' \ "static char const TZVERSION[]=\"$$VERSION\";" \ 'static char const REPORT_BUGS_TO[]="$(BUGEMAIL)";' \ >$@.out mv $@.out $@ zdump: $(TZDOBJS) $(CC) -o $@ $(CFLAGS) $(LDFLAGS) $(TZDOBJS) $(LDLIBS) zic: $(TZCOBJS) $(CC) -o $@ $(CFLAGS) $(LDFLAGS) $(TZCOBJS) $(LDLIBS) leapseconds: $(LEAP_DEPS) $(AWK) -v EXPIRES_LINE=$(EXPIRES_LINE) \ -f leapseconds.awk leap-seconds.list >$@.out mv $@.out $@ # Arguments to pass to submakes of install_data. # They can be overridden by later submake arguments. INSTALLARGS = \ BACKWARD='$(BACKWARD)' \ DESTDIR='$(DESTDIR)' \ LEAPSECONDS='$(LEAPSECONDS)' \ PACKRATDATA='$(PACKRATDATA)' \ PACKRATLIST='$(PACKRATLIST)' \ TZDEFAULT='$(TZDEFAULT)' \ TZDIR='$(TZDIR)' \ ZIC='$(ZIC)' INSTALL_DATA_DEPS = zic leapseconds tzdata.zi # 'make install_data' installs one set of TZif files. install_data: $(INSTALL_DATA_DEPS) $(ZIC_INSTALL) tzdata.zi posix_only: $(INSTALL_DATA_DEPS) $(MAKE) $(INSTALLARGS) LEAPSECONDS= install_data right_only: $(INSTALL_DATA_DEPS) $(MAKE) $(INSTALLARGS) LEAPSECONDS='-L leapseconds' \ install_data # In earlier versions of this makefile, the other two directories were # subdirectories of $(TZDIR). However, this led to configuration errors. # For example, with posix_right under the earlier scheme, # TZ='right/Australia/Adelaide' got you localtime with leap seconds, # but gmtime without leap seconds, which led to problems with applications # like sendmail that subtract gmtime from localtime. # Therefore, the other two directories are now siblings of $(TZDIR). # You must replace all of $(TZDIR) to switch from not using leap seconds # to using them, or vice versa. right_posix: right_only rm -fr '$(DESTDIR)$(TZDIR)-leaps' ln -s '$(TZDIR_BASENAME)' '$(DESTDIR)$(TZDIR)-leaps' || \ $(MAKE) $(INSTALLARGS) TZDIR='$(TZDIR)-leaps' right_only $(MAKE) $(INSTALLARGS) TZDIR='$(TZDIR)-posix' posix_only posix_right: posix_only rm -fr '$(DESTDIR)$(TZDIR)-posix' ln -s '$(TZDIR_BASENAME)' '$(DESTDIR)$(TZDIR)-posix' || \ $(MAKE) $(INSTALLARGS) TZDIR='$(TZDIR)-posix' posix_only $(MAKE) $(INSTALLARGS) TZDIR='$(TZDIR)-leaps' right_only zones: $(REDO) # dummy.zd is not a real file; it is mentioned here only so that the # top-level 'make' does not have a syntax error. ZDS = dummy.zd # Rule used only by submakes invoked by the $(TZS_NEW) rule. # It is separate so that GNU 'make -j' can run instances in parallel. $(ZDS): zdump ./zdump -i $(TZS_CUTOFF_FLAG) '$(wd)/'$$(expr $@ : '\(.*\).zd') \ >$@ TZS_NEW_DEPS = tzdata.zi zdump zic $(TZS_NEW): $(TZS_NEW_DEPS) rm -fr tzs$(TZS_YEAR).dir mkdir tzs$(TZS_YEAR).dir $(zic) -d tzs$(TZS_YEAR).dir tzdata.zi $(AWK) '/^L/{print "Link\t" $$2 "\t" $$3}' \ tzdata.zi | LC_ALL=C sort >$@.out wd=`pwd` && \ x=`$(AWK) '/^Z/{print "tzs$(TZS_YEAR).dir/" $$2 ".zd"}' \ tzdata.zi \ | LC_ALL=C sort -t . -k 2,2` && \ set x $$x && \ shift && \ ZDS=$$* && \ $(MAKE) wd="$$wd" TZS_CUTOFF_FLAG="$(TZS_CUTOFF_FLAG)" \ ZDS="$$ZDS" $$ZDS && \ sed 's,^TZ=".*\.dir/,TZ=",' $$ZDS >>$@.out rm -fr tzs$(TZS_YEAR).dir mv $@.out $@ # If $(TZS) exists but 'make check_tzs' fails, a maintainer should inspect the # failed output and fix the inconsistency, perhaps by running 'make force_tzs'. $(TZS): touch $@ force_tzs: $(TZS_NEW) cp $(TZS_NEW) $(TZS) libtz.a: $(LIBOBJS) rm -f $@ $(AR) -rc $@ $(LIBOBJS) $(RANLIB) $@ date: $(DATEOBJS) $(CC) -o $@ $(CFLAGS) $(LDFLAGS) $(DATEOBJS) $(LDLIBS) tzselect: tzselect.ksh version VERSION=`cat version` && sed \ -e 's|#!/bin/bash|#!$(KSHELL)|g' \ -e 's|AWK=[^}]*|AWK='\''$(AWK)'\''|g' \ -e 's|\(PKGVERSION\)=.*|\1='\''($(PACKAGE)) '\''|' \ -e 's|\(REPORT_BUGS_TO\)=.*|\1=$(BUGEMAIL)|' \ -e 's|TZDIR=[^}]*|TZDIR=$(TZDIR)|' \ -e 's|\(TZVERSION\)=.*|\1='"$$VERSION"'|' \ <$@.ksh >$@.out chmod +x $@.out mv $@.out $@ check: check_back check_mild check_mild: check_character_set check_white_space check_links \ check_name_lengths check_slashed_abbrs check_sorted \ check_tables check_web check_ziguard check_zishrink check_tzs check_character_set: $(ENCHILADA) test ! '$(UTF8_LOCALE)' || \ ! printf 'A\304\200B\n' | \ LC_ALL='$(UTF8_LOCALE)' grep -q '^A.B$$' >/dev/null 2>&1 || { \ LC_ALL='$(UTF8_LOCALE)' && export LC_ALL && \ sharp='#' && \ ! grep -Env $(SAFE_LINE) $(MANS) date.1 $(MANTXTS) \ $(MISC) $(SOURCES) $(WEB_PAGES) \ CONTRIBUTING LICENSE README SECURITY \ version tzdata.zi && \ ! grep -Env $(SAFE_LINE)'|^UNUSUAL_OK_'$(OK_CHAR)'*$$' \ Makefile && \ ! grep -Env $(SAFE_SHARP_LINE) $(TDATA_TO_CHECK) backzone \ leapseconds zone.tab && \ ! grep -Env $(OK_LINE) $(ENCHILADA); \ } touch $@ check_white_space: $(ENCHILADA) patfmt=' \t|[\f\r\v]' && pat=`printf "$$patfmt\\n"` && \ ! grep -En "$$pat" \ $$(ls $(ENCHILADA) | grep -Fvx leap-seconds.list) ! grep -n '[$s]$$' \ $$(ls $(ENCHILADA) | grep -Fvx leap-seconds.list) touch $@ PRECEDES_FILE_NAME = ^(Zone|Link[$s]+[^$s]+)[$s]+ FILE_NAME_COMPONENT_TOO_LONG = $(PRECEDES_FILE_NAME)[^$s]*[^/$s]{15} check_name_lengths: $(TDATA_TO_CHECK) backzone ! grep -En '$(FILE_NAME_COMPONENT_TOO_LONG)' \ $(TDATA_TO_CHECK) backzone touch $@ PRECEDES_STDOFF = ^(Zone[$s]+[^$s]+)?[$s]+ STDOFF = [-+]?[0-9:.]+ RULELESS_SAVE = (-|$(STDOFF)[sd]?) RULELESS_SLASHED_ABBRS = \ $(PRECEDES_STDOFF)$(STDOFF)[$s]+$(RULELESS_SAVE)[$s]+[^$s]*/ check_slashed_abbrs: $(TDATA_TO_CHECK) ! grep -En '$(RULELESS_SLASHED_ABBRS)' $(TDATA_TO_CHECK) touch $@ CHECK_CC_LIST = { n = split($$1,a,/,/); for (i=2; i<=n; i++) print a[1], a[i]; } -check_sorted: backward backzone iso3166.tab zone.tab zone1970.tab +check_sorted: backward backzone $(AWK) '/^Link/ {printf "%.5d %s\n", g, $$3} !/./ {g++}' \ backward | LC_ALL=C sort -cu $(AWK) '/^Zone/ {print $$2}' backzone | LC_ALL=C sort -cu touch $@ check_back: checklinks.awk $(TDATA_TO_CHECK) $(AWK) \ -v DATAFORM=$(DATAFORM) \ -v backcheck=backward \ -f checklinks.awk $(TDATA_TO_CHECK) touch $@ check_links: checklinks.awk tzdata.zi $(AWK) \ -v DATAFORM=$(DATAFORM) \ -f checklinks.awk tzdata.zi touch $@ check_tables: checktab.awk $(YDATA) backward $(ZONETABLES) for tab in $(ZONETABLES); do \ test "$$tab" = zone.tab && links='$(BACKWARD)' || links=''; \ $(AWK) -f checktab.awk -v zone_table=$$tab $(YDATA) $$links \ || exit; \ done touch $@ check_tzs: $(TZS) $(TZS_NEW) if test -s $(TZS); then \ $(DIFF_TZS) $(TZS) $(TZS_NEW); \ else \ cp $(TZS_NEW) $(TZS); \ fi touch $@ check_web: $(CHECK_WEB_PAGES) check_theory.html: theory.html check_tz-art.html: tz-art.html check_tz-how-to.html: tz-how-to.html check_tz-link.html: tz-link.html check_theory.html check_tz-art.html check_tz-how-to.html check_tz-link.html: $(CURL) -sS --url https://validator.w3.org/nu/ -F out=gnu \ -F file=@$$(expr $@ : 'check_\(.*\)') -o $@.out && \ test ! -s $@.out || { cat $@.out; exit 1; } mv $@.out $@ check_ziguard: rearguard.zi vanguard.zi ziguard.awk $(AWK) -v DATAFORM=rearguard -f ziguard.awk vanguard.zi | \ diff -u rearguard.zi - $(AWK) -v DATAFORM=vanguard -f ziguard.awk rearguard.zi | \ diff -u vanguard.zi - touch $@ # Check that zishrink.awk does not alter the data, and that ziguard.awk # preserves main-format data. check_zishrink: check_zishrink_posix check_zishrink_right check_zishrink_posix check_zishrink_right: \ zic leapseconds $(PACKRATDATA) $(PACKRATLIST) \ $(TDATA) $(DATAFORM).zi tzdata.zi rm -fr $@.dir $@-t.dir $@-shrunk.dir mkdir $@.dir $@-t.dir $@-shrunk.dir case $@ in \ *_right) leap='-L leapseconds';; \ *) leap=;; \ esac && \ $(ZIC) $$leap -d $@.dir $(DATAFORM).zi && \ $(ZIC) $$leap -d $@-shrunk.dir tzdata.zi && \ case $(DATAFORM),$(PACKRATLIST) in \ main,) \ $(ZIC) $$leap -d $@-t.dir $(TDATA) && \ $(AWK) '/^Rule/' $(TDATA) | \ $(ZIC) $$leap -d $@-t.dir - $(PACKRATDATA) && \ diff -r $@.dir $@-t.dir;; \ esac diff -r $@.dir $@-shrunk.dir rm -fr $@.dir $@-t.dir $@-shrunk.dir touch $@ clean_misc: rm -fr check_*.dir rm -f *.o *.out $(TIME_T_ALTERNATIVES) \ check_* core typecheck_* \ date tzselect version.h zdump zic libtz.a clean: clean_misc rm -fr *.dir tzdb-*/ rm -f *.zi $(TZS_NEW) maintainer-clean: clean @echo 'This command is intended for maintainers to use; it' @echo 'deletes files that may need special tools to rebuild.' rm -f leapseconds version $(MANTXTS) $(TZS) *.asc *.tar.* names: @echo $(ENCHILADA) public: check check_public $(CHECK_TIME_T_ALTERNATIVES) \ tarballs signatures date.1.txt: date.1 newctime.3.txt: newctime.3 newstrftime.3.txt: newstrftime.3 newtzset.3.txt: newtzset.3 time2posix.3.txt: time2posix.3 tzfile.5.txt: tzfile.5 tzselect.8.txt: tzselect.8 zdump.8.txt: zdump.8 zic.8.txt: zic.8 $(MANTXTS): workman.sh LC_ALL=C sh workman.sh `expr $@ : '\(.*\)\.txt$$'` >$@.out mv $@.out $@ # Set file timestamps deterministically if possible, # so that tarballs containing the timestamps are reproducible. # # '$(SET_TIMESTAMP_N) N DEST A B C ...' sets the timestamp of the # file DEST to the maximum of the timestamps of the files A B C ..., # plus N if GNU ls and touch are available. SET_TIMESTAMP_N = sh -c '\ n=$$0 dest=$$1; shift; \ touch -cmr `ls -t "$$@" | sed 1q` "$$dest" && \ if test $$n != 0 && \ lsout=`ls -n --time-style="+%s" "$$dest" 2>/dev/null`; then \ set x $$lsout && \ touch -cmd @`expr $$7 + $$n` "$$dest"; \ else :; fi' # If DEST depends on A B C ... in this Makefile, callers should use # $(SET_TIMESTAMP_DEP) DEST A B C ..., for the benefit of any # downstream 'make' that considers equal timestamps to be out of date. # POSIX allows this 'make' behavior, and HP-UX 'make' does it. # If all that matters is that the timestamp be reproducible # and plausible, use $(SET_TIMESTAMP). SET_TIMESTAMP = $(SET_TIMESTAMP_N) 0 SET_TIMESTAMP_DEP = $(SET_TIMESTAMP_N) 1 # Set the timestamps to those of the git repository, if available, # and if the files have not changed since then. # This uses GNU 'ls --time-style=+%s', which outputs the seconds count, # and GNU 'touch -d@N FILE', where N is the number of seconds since 1970. # If git or GNU is absent, don't bother to sync with git timestamps. # Also, set the timestamp of each prebuilt file like 'leapseconds' # to be the maximum of the files it depends on. set-timestamps.out: $(EIGHT_YARDS) rm -f $@ if (type git) >/dev/null 2>&1 && \ files=`git ls-files $(EIGHT_YARDS)` && \ touch -md @1 test.out; then \ rm -f test.out && \ for file in $$files; do \ if git diff --quiet $$file; then \ time=`git log -1 --format='tformat:%ct' $$file` && \ touch -cmd @$$time $$file; \ else \ echo >&2 "$$file: warning: does not match repository"; \ fi || exit; \ done; \ fi $(SET_TIMESTAMP_DEP) leapseconds $(LEAP_DEPS) for file in `ls $(MANTXTS) | sed 's/\.txt$$//'`; do \ $(SET_TIMESTAMP_DEP) $$file.txt $$file workman.sh || \ exit; \ done $(SET_TIMESTAMP_DEP) version $(VERSION_DEPS) $(SET_TIMESTAMP_DEP) tzdata.zi $(TZDATA_ZI_DEPS) touch $@ set-tzs-timestamp.out: $(TZS) $(SET_TIMESTAMP_DEP) $(TZS) $(TZS_DEPS) touch $@ # The zics below ensure that each data file can stand on its own. # We also do an all-files run to catch links to links. check_public: $(VERSION_DEPS) rm -fr public.dir mkdir public.dir ln $(VERSION_DEPS) public.dir cd public.dir && $(MAKE) CFLAGS='$(GCC_DEBUG_FLAGS)' ALL for i in $(TDATA_TO_CHECK) public.dir/tzdata.zi \ public.dir/vanguard.zi public.dir/main.zi \ public.dir/rearguard.zi; \ do \ public.dir/zic -v -d public.dir/zoneinfo $$i 2>&1 || exit; \ done public.dir/zic -v -d public.dir/zoneinfo-all $(TDATA_TO_CHECK) : : Also check 'backzone' syntax. rm public.dir/main.zi cd public.dir && $(MAKE) PACKRATDATA=backzone main.zi public.dir/zic -d public.dir/zoneinfo main.zi rm public.dir/main.zi cd public.dir && \ $(MAKE) PACKRATDATA=backzone PACKRATLIST=zone.tab main.zi public.dir/zic -d public.dir/zoneinfo main.zi : rm -fr public.dir touch $@ # Check that the code works under various alternative # implementations of time_t. check_time_t_alternatives: $(TIME_T_ALTERNATIVES) $(TIME_T_ALTERNATIVES_TAIL): $(TIME_T_ALTERNATIVES_HEAD) $(TIME_T_ALTERNATIVES): $(VERSION_DEPS) rm -fr $@.dir mkdir $@.dir ln $(VERSION_DEPS) $@.dir case $@ in \ int*32_t) range=-2147483648,2147483648;; \ u*) range=0,4294967296;; \ *) range=-4294967296,4294967296;; \ esac && \ wd=`pwd` && \ zones=`$(AWK) '/^[^#]/ { print $$3 }' /dev/null; then \ quiet_option='-q'; \ else \ quiet_option=''; \ fi && \ diff $$quiet_option -r $(TIME_T_ALTERNATIVES_HEAD).dir/etc \ $@.dir/etc && \ diff $$quiet_option -r \ $(TIME_T_ALTERNATIVES_HEAD).dir/usr/share \ $@.dir/usr/share; \ } touch $@ TRADITIONAL_ASC = \ tzcode$(VERSION).tar.gz.asc \ tzdata$(VERSION).tar.gz.asc REARGUARD_ASC = \ tzdata$(VERSION)-rearguard.tar.gz.asc ALL_ASC = $(TRADITIONAL_ASC) $(REARGUARD_ASC) \ tzdb-$(VERSION).tar.lz.asc tarballs rearguard_tarballs tailored_tarballs traditional_tarballs \ signatures rearguard_signatures traditional_signatures: \ version set-timestamps.out rearguard.zi vanguard.zi VERSION=`cat version` && \ $(MAKE) AWK='$(AWK)' VERSION="$$VERSION" $@_version # These *_version rules are intended for use if VERSION is set by some # other means. Ordinarily these rules are used only by the above # non-_version rules, which set VERSION on the 'make' command line. tarballs_version: traditional_tarballs_version rearguard_tarballs_version \ tzdb-$(VERSION).tar.lz rearguard_tarballs_version: \ tzdata$(VERSION)-rearguard.tar.gz traditional_tarballs_version: \ tzcode$(VERSION).tar.gz tzdata$(VERSION).tar.gz tailored_tarballs_version: \ tzdata$(VERSION)-tailored.tar.gz signatures_version: $(ALL_ASC) rearguard_signatures_version: $(REARGUARD_ASC) traditional_signatures_version: $(TRADITIONAL_ASC) tzcode$(VERSION).tar.gz: set-timestamps.out LC_ALL=C && export LC_ALL && \ tar $(TARFLAGS) -cf - \ $(COMMON) $(DOCS) $(SOURCES) | \ gzip $(GZIPFLAGS) >$@.out mv $@.out $@ tzdata$(VERSION).tar.gz: set-timestamps.out LC_ALL=C && export LC_ALL && \ tar $(TARFLAGS) -cf - $(TZDATA_DIST) | \ gzip $(GZIPFLAGS) >$@.out mv $@.out $@ # Create empty files with a reproducible timestamp. CREATE_EMPTY = TZ=UTC0 touch -mt 202010122253.00 # The obsolescent *rearguard* targets and related macros are present # for backwards compatibility with tz releases 2018e through 2022a. # They should go away eventually. To build rearguard tarballs you # can instead use 'make DATAFORM=rearguard tailored_tarballs'. tzdata$(VERSION)-rearguard.tar.gz: rearguard.zi set-timestamps.out rm -fr $@.dir mkdir $@.dir ln $(TZDATA_DIST) $@.dir cd $@.dir && rm -f $(TDATA) $(PACKRATDATA) version for f in $(TDATA) $(PACKRATDATA); do \ rearf=$@.dir/$$f; \ $(AWK) -v DATAFORM=rearguard -f ziguard.awk $$f >$$rearf && \ $(SET_TIMESTAMP_DEP) $$rearf ziguard.awk $$f || exit; \ done sed '1s/$$/-rearguard/' $@.dir/version : The dummy pacificnew pacifies TZUpdater 2.3.1 and earlier. $(CREATE_EMPTY) $@.dir/pacificnew touch -cmr version $@.dir/version LC_ALL=C && export LC_ALL && \ (cd $@.dir && \ tar $(TARFLAGS) -cf - \ $(TZDATA_DIST) pacificnew | \ gzip $(GZIPFLAGS)) >$@.out mv $@.out $@ # Create a tailored tarball suitable for TZUpdater and compatible tools. # For example, 'make DATAFORM=vanguard tailored_tarballs' makes a tarball # useful for testing whether TZUpdater supports vanguard form. # The generated tarball is not byte-for-byte equivalent to a hand-tailored # traditional tarball, as data entries are put into 'etcetera' even if they # came from some other source file. However, the effect should be the same # for ordinary use, which reads all the source files. tzdata$(VERSION)-tailored.tar.gz: set-timestamps.out rm -fr $@.dir mkdir $@.dir : The dummy pacificnew pacifies TZUpdater 2.3.1 and earlier. cd $@.dir && \ $(CREATE_EMPTY) $(PRIMARY_YDATA) $(NDATA) backward \ `test $(DATAFORM) = vanguard || echo pacificnew` (grep '^#' tzdata.zi && echo && cat $(DATAFORM).zi) \ >$@.dir/etcetera touch -cmr tzdata.zi $@.dir/etcetera sed -n \ -e '/^# *version *\(.*\)/h' \ -e '/^# *ddeps */H' \ -e '$$!d' \ -e 'g' \ -e 's/^# *version *//' \ -e 's/\n# *ddeps */-/' \ -e 's/ /-/g' \ -e 'p' \ $@.dir/version touch -cmr version $@.dir/version links= && \ for file in $(TZDATA_DIST); do \ test -f $@.dir/$$file || links="$$links $$file"; \ done && \ ln $$links $@.dir LC_ALL=C && export LC_ALL && \ (cd $@.dir && \ tar $(TARFLAGS) -cf - * | gzip $(GZIPFLAGS)) >$@.out mv $@.out $@ tzdb-$(VERSION).tar.lz: set-timestamps.out set-tzs-timestamp.out rm -fr tzdb-$(VERSION) mkdir tzdb-$(VERSION) ln $(ENCHILADA) tzdb-$(VERSION) $(SET_TIMESTAMP) tzdb-$(VERSION) tzdb-$(VERSION)/* LC_ALL=C && export LC_ALL && \ tar $(TARFLAGS) -cf - tzdb-$(VERSION) | lzip -9 >$@.out mv $@.out $@ tzcode$(VERSION).tar.gz.asc: tzcode$(VERSION).tar.gz tzdata$(VERSION).tar.gz.asc: tzdata$(VERSION).tar.gz tzdata$(VERSION)-rearguard.tar.gz.asc: tzdata$(VERSION)-rearguard.tar.gz tzdb-$(VERSION).tar.lz.asc: tzdb-$(VERSION).tar.lz $(ALL_ASC): $(GPG) --armor --detach-sign $? TYPECHECK_CFLAGS = $(CFLAGS) -DTYPECHECK -D__time_t_defined -D_TIME_T typecheck: typecheck_long_long typecheck_unsigned typecheck_long_long typecheck_unsigned: $(VERSION_DEPS) rm -fr $@.dir mkdir $@.dir ln $(VERSION_DEPS) $@.dir cd $@.dir && \ case $@ in \ *_long_long) i="long long";; \ *_unsigned ) i="unsigned" ;; \ esac && \ typecheck_cflags='' && \ $(MAKE) \ CFLAGS="$(TYPECHECK_CFLAGS) \"-Dtime_t=$$i\"" \ TOPDIR="`pwd`" \ install $@.dir/zdump -i -c 1970,1971 Europe/Rome touch $@ zonenames: tzdata.zi @$(AWK) '/^Z/ { print $$2 } /^L/ { print $$3 }' tzdata.zi asctime.o: private.h tzfile.h date.o: private.h difftime.o: private.h localtime.o: private.h tzfile.h strftime.o: private.h tzfile.h zdump.o: version.h zic.o: private.h tzfile.h version.h .PHONY: ALL INSTALL all .PHONY: check check_mild check_time_t_alternatives .PHONY: check_web check_zishrink .PHONY: clean clean_misc dummy.zd force_tzs .PHONY: install install_data maintainer-clean names .PHONY: posix_only posix_right public .PHONY: rearguard_signatures rearguard_signatures_version .PHONY: rearguard_tarballs rearguard_tarballs_version .PHONY: right_only right_posix signatures signatures_version .PHONY: tarballs tarballs_version .PHONY: traditional_signatures traditional_signatures_version .PHONY: traditional_tarballs traditional_tarballs_version .PHONY: tailored_tarballs tailored_tarballs_version .PHONY: typecheck .PHONY: zonenames zones .PHONY: $(ZDS) diff --git a/contrib/tzcode/NEWS b/contrib/tzcode/NEWS index 701e490e4834..b54538aa4a82 100644 --- a/contrib/tzcode/NEWS +++ b/contrib/tzcode/NEWS @@ -1,5902 +1,6013 @@ News for the tz database +Release 2023c - 2023-03-28 12:42:14 -0700 + + Changes to past and future timestamps + + Model Lebanon's DST chaos by reverting data to tzdb 2023a. + (Thanks to Rany Hany for the heads-up.) + + +Release 2023b - 2023-03-23 19:50:38 -0700 + + Changes to future timestamps + + This year Lebanon springs forward April 20/21 not March 25/26. + (Thanks to Saadallah Itani.) [This was reverted in 2023c.] + + +Release 2023a - 2023-03-22 12:39:33 -0700 + + Briefly: + Egypt now uses DST again, from April through October. + This year Morocco springs forward April 23, not April 30. + Palestine delays the start of DST this year. + Much of Greenland still uses DST from 2024 on. + America/Yellowknife now links to America/Edmonton. + tzselect can now use current time to help infer timezone. + The code now defaults to C99 or later. + Fix use of C23 attributes. + + Changes to future timestamps + + Starting in 2023, Egypt will observe DST from April's last Friday + through October's last Thursday. (Thanks to Ahmad ElDardiry.) + Assume the transition times are 00:00 and 24:00, respectively. + + In 2023 Morocco's spring-forward transition after Ramadan + will occur April 23, not April 30. (Thanks to Milamber.) + Adjust predictions for future years accordingly. This affects + predictions for 2023, 2031, 2038, and later years. + + This year Palestine will delay its spring forward from + March 25 to April 29 due to Ramadan. (Thanks to Heba Hamad.) + Make guesses for future Ramadans too. + + Much of Greenland, represented by America/Nuuk, will continue to + observe DST using European Union rules. When combined with + Greenland's decision not to change the clocks in fall 2023, + America/Nuuk therefore changes from -03/-02 to -02/-01 effective + 2023-10-29 at 01:00 UTC. (Thanks to Thomas M. Steenholdt.) + This change from 2022g doesn't affect timestamps until 2024-03-30, + and doesn't affect tm_isdst until 2023-03-25. + + Changes to past timestamps + + America/Yellowknife has changed from a Zone to a backward + compatibility Link, as it no longer differs from America/Edmonton + since 1970. (Thanks to Almaz Mingaleev.) This affects some + pre-1948 timestamps. The old data are now in 'backzone'. + + Changes to past time zone abbreviations + + When observing Moscow time, Europe/Kirov and Europe/Volgograd now + use the abbreviations MSK/MSD instead of numeric abbreviations, + for consistency with other timezones observing Moscow time. + + Changes to code + + You can now tell tzselect local time, to simplify later choices. + Select the 'time' option in its first prompt. + + You can now compile with -DTZNAME_MAXIMUM=N to limit time zone + abbreviations to N bytes (default 255). The reference runtime + library now rejects POSIX-style TZ strings that contain longer + abbreviations, treating them as UTC. Previously the limit was + platform dependent and abbreviations were silently truncated to + 16 bytes even when the limit was greater than 16. + + The code by default is now designed for C99 or later. To build in + a C89 environment, compile with -DPORT_TO_C89. To support C89 + callers of the tzcode library, compile with -DSUPPORT_C89. The + two new macros are transitional aids planned to be removed in a + future version, when C99 or later will be required. + + The code now builds again on pre-C99 platforms, if you compile + with -DPORT_TO_C89. This fixes a bug introduced in 2022f. + + On C23-compatible platforms tzcode no longer uses syntax like + 'static [[noreturn]] void usage(void);'. Instead, it uses + '[[noreturn]] static void usage(void);' as strict C23 requires. + (Problem reported by Houge Langley.) + + The code's functions now constrain their arguments with the C + 'restrict' keyword consistently with their documentation. + This may allow future optimizations. + + zdump again builds standalone with ckdadd and without setenv, + fixing a bug introduced in 2022g. (Problem reported by panic.) + + leapseconds.awk can now process a leap seconds file that never + expires; this might be useful if leap seconds are discontinued. + + Changes to commentary + + tz-link.html has a new section "Coordinating with governments and + distributors". (Thanks to Neil Fuller for some of the text.) + + To improve tzselect diagnostics, zone1970.tab's comments column is + now limited to countries that have multiple timezones. + + Note that leap seconds are planned to be discontinued by 2035. + + Release 2022g - 2022-11-29 08:58:31 -0800 Briefly: The northern edge of Chihuahua changes to US timekeeping. Much of Greenland stops changing clocks after March 2023. Fix some pre-1996 timestamps in northern Canada. C89 is now deprecated; please use C99 or later. Portability fixes for AIX, libintl, MS-Windows, musl, z/OS In C code, use more C23 features if available. C23 timegm now supported by default Fixes for unlikely integer overflows Changes to future timestamps In the Mexican state of Chihuahua, the border strip near the US will change to agree with nearby US locations on 2022-11-30. The strip's western part, represented by Ciudad Juárez, switches from -06 all year to -07/-06 with US DST rules, like El Paso, TX. The eastern part, represented by Ojinaga, will observe US DST next year, like Presidio, TX. (Thanks to Heitor David Pinto.) A new Zone America/Ciudad_Juarez splits from America/Ojinaga. Much of Greenland, represented by America/Nuuk, stops observing winter time after March 2023, so its daylight saving time becomes standard time. (Thanks to Jonas Nyrup and Jürgen Appel.) Changes to past timestamps Changes for pre-1996 northern Canada (thanks to Chris Walton): Merge America/Iqaluit and America/Pangnirtung into the former, with a backward compatibility link for the latter name. There is no good evidence the two locations differ since 1970. This change affects pre-1996 America/Pangnirtung timestamps. Cambridge Bay, Inuvik, Iqaluit, Rankin Inlet, Resolute and Yellowknife did not observe DST in 1965, and did observe DST from 1972 through 1979. Whitehorse moved from -09 to -08 on 1966-02-27, not 1967-05-28. Colombia's 1993 fallback was 02-06 24:00, not 04-04 00:00. (Thanks to Alois Treindl.) Singapore's 1981-12-31 change was at 16:00 UTC (23:30 local time), not 24:00 local time. (Thanks to Geoff Clare via Robert Elz.) Changes to code Although tzcode still works with C89, bugs found in recent routine maintenance indicate that bitrot has set in and that in practice C89 is no longer used to build tzcode. As it is a maintenance burden, support for C89 is planned to be removed soon. Instead, please use compilers compatible with C99, C11, C17, or C23. timegm, which tzcode implemented in 1989, will finally be standardized 34 years later as part of C23, so timegm is now supported even if STD_INSPIRED is not defined. Fix bug in zdump's tzalloc emulation on hosts that lack tm_zone. (Problem reported by Đoàn Trần Công Danh.) Fix bug in zic on hosts where malloc(0) yields NULL on success. (Problem reported by Tim McBrayer for AIX 6.1.) Fix zic configuration to avoid linkage failures on some platforms. (Problems reported by Gilmore Davidson and Igor Ivanov.) Work around MS-Windows nmake incompatibility with POSIX. (Problem reported by Manuela Friedrich.) Port mktime and strftime to debugging platforms where accessing uninitialized data has undefined behavior (strftime problem reported by Robert Elz). Check more carefully for unlikely integer overflows, preferring C23 to overflow checking by hand, as the latter has had obscure bugs. Changes to build procedure New Makefile rule check_mild that skips checking whether Link lines are in the file 'backward'. (Inspired by a suggestion from Stephen Colebourne.) Release 2022f - 2022-10-28 18:04:57 -0700 Briefly: Mexico will no longer observe DST except near the US border. Chihuahua moves to year-round -06 on 2022-10-30. Fiji no longer observes DST. Move links to 'backward'. In vanguard form, GMT is now a Zone and Etc/GMT a link. zic now supports links to links, and vanguard form uses this. Simplify four Ontario zones. Fix a Y2438 bug when reading TZif data. Enable 64-bit time_t on 32-bit glibc platforms. Omit large-file support when no longer needed. In C code, use some C23 features if available. Remove no-longer-needed workaround for Qt bug 53071. Changes to future timestamps Mexico will no longer observe DST after 2022, except for areas near the US border that continue to observe US DST rules. On 2022-10-30 at 02:00 the Mexican state of Chihuahua moves from -07 (-06 with DST) to year-round -06, thus not changing its clocks that day. The new law states that Chihuahua near the US border no longer observes US DST. (Thanks to gera for the heads-up about Chihuahua.) Fiji will not observe DST in 2022/3. (Thanks to Shalvin Narayan.) For now, assume DST is suspended indefinitely. Changes to data Move links to 'backward' to ease and simplify link maintenance. This affects generated data only if you use 'make BACKWARD='. GMT is now a Zone and Etc/GMT a link instead of vice versa, as GMT is needed for leap second support whereas Etc/GMT is not. However, this change exposes a bug in TZUpdater 2.3.2 so it is present only in vanguard form for now. Vanguard form now uses links to links, as zic now supports this. Changes to past timestamps Simplify four Ontario zones, as most of the post-1970 differences seem to have been imaginary. (Problem reported by Chris Walton.) Move America/Nipigon, America/Rainy_River, and America/Thunder_Bay to 'backzone'; backward-compatibility links still work, albeit with some different timestamps before November 2005. Changes to code zic now supports links to links regardless of input line order. For example, if Australia/Sydney is a Zone, the lines Link Australia/Canberra Australia/ACT Link Australia/Sydney Australia/Canberra now work correctly, even though the shell commands ln Australia/Canberra Australia/ACT ln Australia/Sydney Australia/Canberra would fail because the first command attempts to use a link Australia/Canberra that does not exist until after the second command is executed. Previously, zic had unspecified behavior if a Link line's target was another link, and zic often misbehaved if a Link line's target was a later Link line. Fix line number in zic's diagnostic for a link to a link. Fix a bug that caused localtime to mishandle timestamps starting in the year 2438 when reading data generated by 'zic -b fat' when distant-future DST transitions occur at times given in standard time or in UT, not the usual case of local time. This occurs when the corresponding .zi Rule lines specify DST transitions with TO columns of 'max' and AT columns that end in 's' or 'u'. The number 2438 comes from the 32-bit limit in the year 2038, plus the 400-year Gregorian cycle. (Problem reported by Bradley White.) On glibc 2.34 and later, which optionally supports 64-bit time_t on platforms like x86 where time_t was traditionally 32 bits, default time_t to 64 instead of 32 bits. This lets functions like localtime support timestamps after the year 2038, and fixes year-2038 problems in zic when accessing files dated after 2038. To continue to limit time_t to 32 bits on these platforms, use "make CFLAGS='-D_TIME_BITS=32'". In C code, do not enable large-file support on platforms like AIX and macOS that no longer need it now that tzcode does not use off_t or related functions like 'stat'. Large-file support is still enabled by default on GNU/Linux, as it is needed for 64-bit time_t support. In C code, prefer C23 keywords to pre-C23 macros for alignof, bool, false, and true. Also, use the following C23 features if available: __has_include, unreachable. zic no longer works around Qt bug 53071, as the relevant Qt releases have been out of support since 2019. This change affects only fat TZif files, as thin files never had the workaround. zdump no longer modifies the environ vector when compiled on platforms lacking tm_zone or when compiled with -DUSE_LTZ=0. This avoid undefined behavior on POSIX platforms. Release 2022e - 2022-10-11 11:13:02 -0700 Briefly: Jordan and Syria switch from +02/+03 with DST to year-round +03. Changes to future timestamps Jordan and Syria are abandoning the DST regime and are changing to permanent +03, so they will not fall back from +03 to +02 on 2022-10-28. (Thanks to Steffen Thorsen and Issam Al-Zuwairi.) Changes to past timestamps On 1922-01-01 Tijuana adopted standard time at 00:00, not 01:00. Changes to past time zone abbreviations and DST flags The temporary advancement of clocks in central Mexico in summer 1931 is now treated as daylight saving time, instead of as two changes to standard time. Release 2022d - 2022-09-23 12:02:57 -0700 Briefly: Palestine transitions are now Saturdays at 02:00. Simplify three Ukraine zones into one. Changes to future timestamps Palestine now springs forward and falls back at 02:00 on the first Saturday on or after March 24 and October 24, respectively. This means 2022 falls back 10-29 at 02:00, not 10-28 at 01:00. (Thanks to Heba Hamad.) Changes to past timestamps Simplify three Ukraine zones to one, since the post-1970 differences seem to have been imaginary. Move Europe/Uzhgorod and Europe/Zaporozhye to 'backzone'; backward-compatibility links still work, albeit with different timestamps before October 1991. Release 2022c - 2022-08-15 17:47:18 -0700 Briefly: Work around awk bug in FreeBSD, macOS, etc. Improve tzselect on intercontinental Zones. Changes to code Work around a bug in onetrueawk that broke commands like 'make traditional_tarballs' on FreeBSD, macOS, etc. (Problem reported by Deborah Goldsmith.) Add code to tzselect that uses experimental structured comments in zone1970.tab to clarify whether Zones like Africa/Abidjan and Europe/Istanbul cross continent or ocean boundaries. (Inspired by a problem reported by Peter Krefting.) Fix bug with 'zic -d /a/b/c' when /a is unwritable but the directory /a/b already exists. Remove zoneinfo2tdf.pl, as it was unused and triggered false malware alarms on some email servers. Release 2022b - 2022-08-10 15:38:32 -0700 Briefly: Chile's DST is delayed by a week in September 2022. Iran no longer observes DST after 2022. Rename Europe/Kiev to Europe/Kyiv. New zic -R option Vanguard form now uses %z. Finish moving duplicate-since-1970 zones to 'backzone'. New build option PACKRATLIST New tailored_tarballs target, replacing rearguard_tarballs Changes to future timestamps Chile's 2022 DST start is delayed from September 4 to September 11. (Thanks to Juan Correa.) Iran plans to stop observing DST permanently, after it falls back on 2022-09-21. (Thanks to Ali Mirjamali.) Changes to past timestamps Finish moving to 'backzone' the location-based zones whose timestamps since 1970 are duplicates; adjust links accordingly. This change ordinarily affects only pre-1970 timestamps, and with the new PACKRATLIST option it does not affect any timestamps. In this round the affected zones are Antarctica/Vostok, Asia/Brunei, Asia/Kuala_Lumpur, Atlantic/Reykjavik, Europe/Amsterdam, Europe/Copenhagen, Europe/Luxembourg, Europe/Monaco, Europe/Oslo, Europe/Stockholm, Indian/Christmas, Indian/Cocos, Indian/Kerguelen, Indian/Mahe, Indian/Reunion, Pacific/Chuuk, Pacific/Funafuti, Pacific/Majuro, Pacific/Pohnpei, Pacific/Wake and Pacific/Wallis, and the affected links are Arctic/Longyearbyen, Atlantic/Jan_Mayen, Iceland, Pacific/Ponape, Pacific/Truk, and Pacific/Yap. From fall 1994 through fall 1995, Shanks wrote that Crimea's DST transitions were at 02:00 standard time, not at 00:00. (Thanks to Michael Deckers.) Iran adopted standard time in 1935, not 1946. In 1977 it observed DST from 03-21 23:00 to 10-20 24:00; its 1978 transitions were on 03-24 and 08-05, not 03-20 and 10-20; and its spring 1979 transition was on 05-27, not 03-21. (Thanks to Roozbeh Pournader and Francis Santoni.) Chile's observance of -04 from 1946-08-29 through 1947-03-31 was considered DST, not standard time. Santiago and environs had moved their clocks back to rejoin the rest of mainland Chile; put this change at the end of 1946-08-28. (Thanks to Michael Deckers.) Some old, small clock transitions have been removed, as people at the time did not change their clocks. This affects Asia/Hong_Kong in 1904, Asia/Ho_Chi_Minh in 1906, and Europe/Dublin in 1880. Changes to zone name Rename Europe/Kiev to Europe/Kyiv, as "Kyiv" is more common in English now. Spelling of other names in Ukraine has not yet demonstrably changed in common English practice so for now these names retain old spellings, as in other countries (e.g., Europe/Prague not "Praha", and Europe/Sofia not "Sofiya"). Changes to code zic has a new option '-R @N' to output explicit transitions < N. (Need suggested by Almaz Mingaleev.) 'zic -r @N' no longer outputs bad data when N < first transition. (Problem introduced in 2021d and reported by Peter Krefting.) zic now checks its input for NUL bytes and unterminated lines, and now supports input line lengths up to 2048 (not 512) bytes. gmtime and related code now use the abbreviation "UTC" not "GMT". POSIX is being revised to require this. When tzset and related functions set vestigial static variables like tzname, they now prefer specified timestamps to unspecified ones. (Problem reported by Almaz Mingaleev.) zic no longer complains "can't determine time zone abbreviation to use just after until time" when a transition to a new standard time occurs simultaneously with the first DST fallback transition. Changes to build procedure Source data in vanguard form now uses the %z notation, introduced in release 2015f. For example, for America/Sao_Paulo vanguard form contains the zone continuation line "-3:00 Brazil %z", which is simpler and more reliable than the line "-3:00 Brazil -03/-02" used in main and rearguard forms. The plan is for the main form to use %z eventually; in the meantime maintainers of zi parsers are encouraged to test the parsers on vanguard.zi. The Makefile has a new PACKRATLIST option to select a subset of 'backzone'. For example, 'make PACKRATDATA=backzone PACKRATLIST=zone.tab' now generates TZif files identical to those of the global-tz project. The Makefile has a new tailored_tarballs target for generating special-purpose tarballs. It generalizes and replaces the rearguard_tarballs target and related targets and macros, which are now obsolescent. 'make install' now defaults LOCALTIME to Factory not GMT, which means the default abbreviation is now "-00" not "GMT". Remove the posix_packrat target, marked obsolescent in 2016a. Release 2022a - 2022-03-15 23:02:01 -0700 Briefly: Palestine will spring forward on 2022-03-27, not -03-26. zdump -v now outputs better failure indications. Bug fixes for code that reads corrupted TZif data. Changes to future timestamps Palestine will spring forward on 2022-03-27, not 2022-03-26. (Thanks to Heba Hamad.) Predict future transitions for first Sunday >= March 25. Additionally, predict fallbacks to be the first Friday on or after October 23, not October's last Friday, to be more consistent with recent practice. The first differing fallback prediction is on 2025-10-24, not 2025-10-31. Changes to past timestamps From 1992 through spring 1996, Ukraine's DST transitions were at 02:00 standard time, not at 01:00 UTC. (Thanks to Alois Treindl.) Chile's Santiago Mean Time and its LMT precursor have been adjusted eastward by 1 second to align with past and present law. Changes to commentary Add several references for Chile's 1946/1947 transitions, some of which only affected portions of the country. Changes to code Fix bug when mktime gets confused by truncated TZif files with unspecified local time. (Problem reported by Almaz Mingaleev.) Fix bug when 32-bit time_t code reads malformed 64-bit TZif data. (Problem reported by Christos Zoulas.) When reading a version 2 or later TZif file, the TZif reader now validates the version 1 header and data block only enough to skip over them, as recommended by RFC 8536 section 4. Also, the TZif reader no longer mistakenly attempts to parse a version 1 TZIf file header as a TZ string. zdump -v now outputs "(localtime failed)" and "(gmtime failed)" when local time and UT cannot be determined for a timestamp. Changes to build procedure Distribution tarballs now use standard POSIX.1-1988 ustar format instead of GNU format. Although the formats are almost identical for these tarballs, ustar headers' magic fields contain "ustar" instead of "ustar ", and their version fields contain "00" instead of " ". The two formats are planned to diverge more significantly for tzdb releases after 2242-03-16 12:56:31 UTC, when the ustar format becomes obsolete and the tarballs switch to pax format, an extension of ustar. For details about these formats, please see "pax - portable archive interchange", IEEE Std 1003.1-2017, . Release 2021e - 2021-10-21 18:41:00 -0700 Changes to future timestamps Palestine will fall back 10-29 (not 10-30) at 01:00. (Thanks to P Chan and Heba Hemad.) Release 2021d - 2021-10-15 13:48:18 -0700 Briefly: Fiji suspends DST for the 2021/2022 season. 'zic -r' marks unspecified timestamps with "-00". Changes to future timestamps Fiji will suspend observance of DST for the 2021/2022 season. Assume for now that it will return next year. (Thanks to Jashneel Kumar and P Chan.) Changes to code 'zic -r' now uses "-00" time zone abbreviations for intervals with UT offsets that are unspecified due to -r truncation. This implements a change in draft Internet RFC 8536bis. Release 2021c - 2021-10-01 14:21:49 -0700 Briefly: Revert most 2021b changes to 'backward'. Fix 'zic -b fat' bug in pre-1970 32-bit data. Fix two Link line typos. Distribute SECURITY file. This release is intended as a bugfix release, to fix compatibility problems and typos reported since 2021b was released. Changes to Link directives Revert almost all of 2021b's changes to the 'backward' file, by moving Link directives back to where they were in 2021a. Although 'zic' doesn't care which source file contains a Link directive, some downstream uses ran into trouble with the move. (Problem reported by Stephen Colebourne for Joda-Time.) Fix typo that linked Atlantic/Jan_Mayen to the wrong location (problem reported by Chris Walton). Fix 'backzone' typo that linked America/Virgin to the wrong location (problem reported by Michael Deckers). Changes to code Fix a bug in 'zic -b fat' that caused old timestamps to be mishandled in 32-bit-only readers (problem reported by Daniel Fischer). Changes to documentation Distribute the SECURITY file (problem reported by Andreas Radke). Release 2021b - 2021-09-24 16:23:00 -0700 Briefly: Jordan now starts DST on February's last Thursday. Samoa no longer observes DST. Merge more location-based Zones whose timestamps agree since 1970. Move some backward-compatibility links to 'backward'. Rename Pacific/Enderbury to Pacific/Kanton. Correct many pre-1993 transitions in Malawi, Portugal, etc. zic now creates each output file or link atomically. zic -L no longer omits the POSIX TZ string in its output. zic fixes for truncation and leap second table expiration. zic now follows POSIX for TZ strings using all-year DST. Fix some localtime crashes and bugs in obscure cases. zdump -v now outputs more-useful boundary cases. tzfile.5 better matches a draft successor to RFC 8536. A new file SECURITY. This release is prompted by recent announcements by Jordan and Samoa. It incorporates many other changes that had accumulated since 2021a. However, it omits most proposed changes that merged all Zones agreeing since 1970, as concerns were raised about doing too many of these changes at once. It does keeps some of these changes in the interest of making tzdb more equitable one step at a time; see "Merge more location-based Zones" below. Changes to future timestamps Jordan now starts DST on February's last Thursday. (Thanks to Steffen Thorsen.) Samoa no longer observes DST. (Thanks to Geoffrey D. Bennett.) Changes to zone name Rename Pacific/Enderbury to Pacific/Kanton. When we added Enderbury in 1993, we did not know that it is uninhabited and that Kanton (population two dozen) is the only inhabited location in that timezone. The old name is now a backward-compatibility link. Changes to past timestamps Correct many pre-1993 transitions, fixing entries originally derived from Shanks, Whitman, and Mundell. The fixes include: - Barbados: standard time was introduced in 1911, not 1932; and DST was observed in 1942-1944 - Cook Islands: In 1899 they switched from east to west of GMT, celebrating Christmas for two days. They (and Niue) switched to standard time in 1952, not 1901. - Guyana: corrected LMT for Georgetown; the introduction of standard time in 1911, not 1915; and corrections to 1975 and 1992 transitions - Kanton: uninhabited before 1937-08-31 - Niue: only observed -11:20 from 1952 through 1964, then went to -11 instead of -11:30 - Portugal: DST was observed in 1950 - Tonga: corrected LMT; the introduction of standard time in 1945, not 1901; and corrections to the transition from +12:20 to +13 in 1961, not 1941 Additional fixes to entries in the 'backzone' file include: - Enderbury: inhabited only 1860/1885 and 1938-03-06/1942-02-09 - The Gambia: 1933 and 1942 transitions - Malawi: several 1911 through 1925 transitions - Sierra Leone: several 1913 through 1941 transitions, and DST was NOT observed in 1957 through 1962 (Thanks to P Chan, Michael Deckers, Alexander Krivenyshev and Alois Treindl.) Merge more location-based Zones whose timestamps agree since 1970, as pre-1970 timestamps are out of scope. This is part of a process that has been ongoing since 2013. This does not affect post-1970 timestamps, and timezone historians who build with 'make PACKRATDATA=backzone' should see no changes to pre-1970 timestamps. When merging, keep the most-populous location's data, and move data for other locations to 'backzone' with a backward link in 'backward'. For example, move America/Creston data to 'backzone' with a link in 'backward' from America/Phoenix because the two timezones' timestamps agree since 1970; this change affects some pre-1968 timestamps in America/Creston because Creston and Phoenix disagreed before 1968. The affected Zones are Africa/Accra, America/Atikokan, America/Blanc-Sablon, America/Creston, America/Curacao, America/Nassau, America/Port_of_Spain, Antarctica/DumontDUrville, and Antarctica/Syowa. Changes to maintenance procedure The new file SECURITY covers how to report security-related bugs. Several backward-compatibility links have been moved to the 'backward' file. These links, which range from Africa/Addis_Ababa to Pacific/Saipan, are only for compatibility with now-obsolete guidelines suggesting an entry for every ISO 3166 code. The intercontinental convenience links Asia/Istanbul and Europe/Nicosia have also been moved to 'backward'. Changes to code zic now creates each output file or link atomically, possibly by creating a temporary file and then renaming it. This avoids races where a TZ setting would temporarily stop working while zic was installing a replacement file or link. zic -L no longer omits the POSIX TZ string in its output. Starting with 2020a, zic -L truncated its output according to the "Expires" directive or "#expires" comment in the leapseconds file. The resulting TZif files omitted daylight saving transitions after - the leap second table expired, which led to far less-accurate + the leap second table expired, which led to far less accurate predictions of times after the expiry. Although future timestamps cannot be converted accurately in the presence of leap seconds, it is more accurate to convert near-future timestamps with a few seconds error than with an hour error, so zic -L no longer truncates output in this way. Instead, when zic -L is given the "Expires" directive, it now outputs the expiration by appending a no-change entry to the leap second table. Although this should work well with most TZif readers, it does not conform to Internet RFC 8536 and some pickier clients (including tzdb 2017c through 2021a) reject it, so "Expires" directives are currently disabled by default. To enable them, set the EXPIRES_LINE Makefile variable. If a TZif file uses this new feature it is marked with a new TZif version number 4, a format intended to be documented in a successor to RFC 8536. zic -L LEAPFILE -r @LO no longer generates an invalid TZif file that omits leap second information for the range LO..B when LO falls between two leap seconds A and B. Instead, it generates a - TZif version 4 file that represents the previously-missing + TZif version 4 file that represents the previously missing information. The TZif reader now allows the leap second table to begin with a correction other than -1 or +1, and to contain adjacent transitions with equal corrections. This supports TZif version 4. The TZif reader now lets leap seconds occur less than 28 days apart. This supports possible future TZif extensions. Fix bug that caused 'localtime' etc. to crash when TZ was set to a all-year DST string like "EST5EDT4,0/0,J365/25" that does not conform to POSIX but does conform to Internet RFC 8536. Fix another bug that caused 'localtime' etc. to crash when TZ was set to a POSIX-conforming but unusual TZ string like "EST5EDT4,0/0,J365/0", where almost all the year is DST. Fix yet another bug that caused 'localtime' etc. to mishandle slim TZif files containing leap seconds after the last explicit transition in the table, or when handling far-future timestamps in slim TZif files lacking leap seconds. Fix localtime misbehavior involving positive leap seconds. This change affects only behavior for "right" system time, which contains leap seconds, and only if the UT offset is not a multiple of 60 seconds when a positive leap second occurs. (No such timezone exists in tzdb, luckily.) Without the fix, the timestamp was ambiguous during a positive leap second. With the fix, any seconds occurring after a positive leap second and within the same localtime minute are counted through 60, not through 59; their UT offset (tm_gmtoff) is the same as before. Here is how the fix affects timestamps in a timezone with UT offset +01:23:45 (5025 seconds) and with a positive leap second at 1972-06-30 23:59:60 UTC (78796800): time_t without the fix with the fix 78796800 1972-07-01 01:23:45 1972-07-01 01:23:45 (leap second) 78796801 1972-07-01 01:23:45 1972-07-01 01:23:46 ... 78796815 1972-07-01 01:23:59 1972-07-01 01:23:60 78796816 1972-07-01 01:24:00 1972-07-01 01:24:00 Fix an unlikely bug that caused 'localtime' etc. to misbehave if civil time changes a few seconds before time_t wraps around, when leap seconds are enabled. Fix bug in zic -r; in some cases, the dummy time type after the last time transition disagreed with the TZ string, contrary to Internet RFC 8563 section 3.3. Fix a bug with 'zic -r @X' when X is a negative leap second that has a nonnegative correction. Without the fix, the output file was truncated so that X appeared to be a positive leap second. - Fix a similar, even-less-likely bug when truncating at a positive + Fix a similar, even less likely bug when truncating at a positive leap second that has a nonpositive correction. zic -r now reports an error if given rolling leap seconds, as this usage has never generally worked and is evidently unused. zic now generates a POSIX-conforming TZ string for TZif files where all-year DST is predicted for the indefinite future. For example, for all-year Eastern Daylight Time, zic now generates "XXX3EDT4,0/0,J365/23" where it previously generated "EST5EDT,0/0,J365/25" or "". (Thanks to Michael Deckers for noting the possibility of POSIX conformance.) zic.c no longer requires sys/wait.h (thanks to spazmodius for noting it wasn't needed). When reading slim TZif files, zdump no longer mishandles leap seconds on the rare platforms where time_t counts leap seconds, fixing a bug introduced in 2014g. zdump -v now outputs timestamps at boundaries of what localtime - and gmtime can represent, instead of the less-useful timestamps + and gmtime can represent, instead of the less useful timestamps one day after the minimum and one day before the maximum. (Thanks to Arthur David Olson for prototype code, and to Manuela Friedrich for debugging help.) zdump's -c and -t options are now consistently inclusive for the lower time bound and exclusive for the upper. Formerly they were inconsistent. (Confusion noted by Martin Burnicki.) Changes to build procedure You can now compile with -DHAVE_MALLOC_ERRNO=0 to port to non-POSIX hosts where malloc doesn't set errno. (Problem reported by Jan Engelhardt.) Changes to documentation tzfile.5 better matches a draft successor to RFC 8536 . Release 2021a - 2021-01-24 10:54:57 -0800 Changes to future timestamps South Sudan changes from +03 to +02 on 2021-02-01 at 00:00. (Thanks to Steffen Thorsen.) Release 2020f - 2020-12-29 00:17:46 -0800 Change to build procedure 'make rearguard_tarballs' no longer generates a bad rearguard.zi, fixing a 2020e bug. (Problem reported by Deborah Goldsmith.) Release 2020e - 2020-12-22 15:14:34 -0800 Briefly: Volgograd switches to Moscow time on 2020-12-27 at 02:00. Changes to future timestamps Volgograd changes time zone from +04 to +03 on 2020-12-27 at 02:00. (Thanks to Alexander Krivenyshev and Stepan Golosunov.) Changes to past timestamps Correct many pre-1986 transitions, fixing entries originally derived from Shanks. The fixes include: - Australia: several 1917 through 1971 transitions - The Bahamas: several 1941 through 1945 transitions - Bermuda: several 1917 through 1956 transitions - Belize: several 1942 through 1968 transitions - Ghana: several 1915 through 1956 transitions - Israel and Palestine: several 1940 through 1985 transitions - Kenya and adjacent: several 1908 through 1960 transitions - Nigeria and adjacent: correcting LMT in Lagos, and several 1905 through 1919 transitions - Seychelles: the introduction of standard time in 1907, not 1906 - Vanuatu: DST in 1973-1974, and a corrected 1984 transition (Thanks to P Chan.) Because of the Australia change, Australia/Currie (King Island) is no longer needed, as it is identical to Australia/Hobart for all timestamps since 1970 and was therefore created by mistake. Australia/Currie has been moved to the 'backward' file and its corrected data moved to the 'backzone' file. Changes to past time zone abbreviations and DST flags To better match legislation in Turks and Caicos, the 2015 shift to year-round observance of -04 is now modeled as AST throughout before returning to Eastern Time with US DST in 2018, rather than as maintaining EDT until 2015-11-01. (Thanks to P Chan.) Changes to documentation The zic man page now documents zic's coalescing of transitions when a zone falls back just before DST springs forward. Release 2020d - 2020-10-21 11:24:13 -0700 Briefly: Palestine ends DST earlier than predicted, on 2020-10-24. Changes to past and future timestamps Palestine ends DST on 2020-10-24 at 01:00, instead of 2020-10-31 as previously predicted (thanks to Sharef Mustafa.) Its 2019-10-26 fall-back was at 00:00, not 01:00 (thanks to Steffen Thorsen.) Its 2015-10-23 transition was at 01:00 not 00:00, and its spring 2020 transition was on March 28 at 00:00, not March 27 (thanks to Pierre Cashon.) This affects Asia/Gaza and Asia/Hebron. Assume future spring and fall transitions will be on the Saturday preceding the last Sunday of March and October, respectively. Release 2020c - 2020-10-16 11:15:53 -0700 Briefly: Fiji starts DST later than usual, on 2020-12-20. Changes to future timestamps Fiji will start DST on 2020-12-20, instead of 2020-11-08 as previously predicted. DST will still end on 2021-01-17. (Thanks to Raymond Kumar and Alan Mintz.) Assume for now that the later-than-usual start date is a one-time departure from the recent pattern. Changes to build procedure Rearguard tarballs now contain an empty file pacificnew. Some older downstream software expects this file to exist. (Problem reported by Mike Cullinan.) Release 2020b - 2020-10-06 18:35:04 -0700 Briefly: Revised predictions for Morocco's changes starting in 2023. Canada's Yukon changes to -07 on 2020-11-01, not 2020-03-08. Macquarie Island has stayed in sync with Tasmania since 2011. Casey, Antarctica is at +08 in winter and +11 in summer. zic no longer supports -y, nor the TYPE field of Rules. Changes to future timestamps Morocco's spring-forward after Ramadan is now predicted to occur no sooner than two days after Ramadan, instead of one day. (Thanks to Milamber.) The first altered prediction is for 2023, now predicted to spring-forward on April 30 instead of April 23. Changes to past and future timestamps Casey Station, Antarctica has been using +08 in winter and +11 in summer since 2018. The most recent transition from +08 to +11 was 2020-10-04 00:01. Also, Macquarie Island has been staying in sync with Tasmania since 2011. (Thanks to Steffen Thorsen.) Changes to past and future time zone abbreviations and DST flags Canada's Yukon, represented by America/Whitehorse and America/Dawson, changes its time zone rules from -08/-07 to permanent -07 on 2020-11-01, not on 2020-03-08 as 2020a had it. This change affects only the time zone abbreviation (MST vs PDT) and daylight saving flag for the period between the two dates. (Thanks to Andrew G. Smith.) Changes to past timestamps Correct several transitions for Hungary for 1918/1983. For example, the 1983-09-25 fall-back was at 01:00, not 03:00. (Thanks to Géza Nyáry.) Also, the 1890 transition to standard time was on 11-01, not 10-01 (thanks to Michael Deckers). The 1891 French transition was on March 16, not March 15. The 1911-03-11 French transition was at midnight, not a minute later. Monaco's transitions were on 1892-06-01 and 1911-03-29, not 1891-03-15 and 1911-03-11. (Thanks to Michael Deckers.) Changes to code Support for zic's long-obsolete '-y YEARISTYPE' option has been removed and, with it, so has support for the TYPE field in Rule lines, which is now reserved for compatibility with earlier zic. These features were previously deprecated in release 2015f. (Thanks to Tim Parenti.) zic now defaults to '-b slim' instead of to '-b fat'. zic's new '-l -' and '-p -' options uninstall any existing localtime and posixrules files, respectively. The undocumented and ineffective tzsetwall function has been removed. Changes to build procedure The Makefile now defaults POSIXRULES to '-', so the posixrules feature (obsolete as of 2019b) is no longer installed by default. Changes to documentation and commentary The long-obsolete files pacificnew, systemv, and yearistype.sh have been removed from the distribution. (Thanks to Tim Parenti.) Release 2020a - 2020-04-23 16:03:47 -0700 Briefly: Morocco springs forward on 2020-05-31, not 2020-05-24. Canada's Yukon advanced to -07 year-round on 2020-03-08. America/Nuuk renamed from America/Godthab. zic now supports expiration dates for leap second lists. Changes to future timestamps Morocco's second spring-forward transition in 2020 will be May 31, not May 24 as predicted earlier. (Thanks to Semlali Naoufal.) Adjust future-year predictions to use the first Sunday after the day after Ramadan, not the first Sunday after Ramadan. Canada's Yukon, represented by America/Whitehorse and America/Dawson, advanced to -07 year-round, beginning with its spring-forward transition on 2020-03-08, and will not fall back on 2020-11-01. Although a government press release calls this "permanent Pacific Daylight Saving Time", we prefer MST for consistency with nearby Dawson Creek, Creston, and Fort Nelson. (Thanks to Tim Parenti.) Changes to past timestamps Shanghai observed DST in 1919. (Thanks to Phake Nick.) Changes to timezone identifiers To reflect current usage in English better, America/Godthab has been renamed to America/Nuuk. A backwards-compatibility link remains for the old name. Changes to code localtime.c no longer mishandles timestamps after the last transition in a TZif file with leap seconds and with daylight saving time transitions projected into the indefinite future. For example, with TZ='America/Los_Angeles' with leap seconds, zdump formerly reported a DST transition on 2038-03-14 from 01:59:32.999... to 02:59:33 instead of the correct transition from 01:59:59.999... to 03:00:00. zic -L now supports an Expires line in the leapseconds file, and truncates the TZif output accordingly. This propagates leap second expiration information into the TZif file, and avoids the abovementioned localtime.c bug as well as similar bugs present in many client implementations. If no Expires line is present, zic -L instead truncates the TZif output based on the #expires comment present in leapseconds files distributed by tzdb 2018f and later; however, this usage is obsolescent. For now, the distributed leapseconds file has an Expires line that is commented out, so that the file can be fed to older versions of zic which ignore the commented-out line. Future tzdb distributions are planned to contain a leapseconds file with an Expires line. The configuration macros HAVE_TZNAME and USG_COMPAT should now be set to 1 if the system library supports the feature, and 2 if not. As before, these macros are nonzero if tzcode should support the feature, zero otherwise. The configuration macro ALTZONE now has the same values with the same meaning as HAVE_TZNAME and USG_COMPAT. The code's defense against CRLF in leap-seconds.list is now portable to POSIX awk. (Problem reported by Deborah Goldsmith.) Although the undocumented tzsetwall function is not changed in this release, it is now deprecated in preparation for removal in future releases. Due to POSIX requirements, tzsetwall has not worked for some time. Any code that uses it should instead use tzalloc(NULL) or, if portability trumps thread-safety, should unset the TZ environment variable. Changes to commentary The Îles-de-la-Madeleine and the Listuguj reserve are noted as following America/Halifax, and comments about Yukon's "south" and "north" have been corrected to say "east" and "west". (Thanks to Jeffery Nichols.) 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 Treindl 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 Treindl.) 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 . 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.) East Kiribati 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 inadvertently 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 + smaller 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 + 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 . (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 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. + 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. + '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 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 (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. + 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 + 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 + 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 + 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". + 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 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. + 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 . 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 Rethans'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 "
" 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
+  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:
diff --git a/contrib/tzcode/asctime.c b/contrib/tzcode/asctime.c
index 1a6486f38163..b129ea22dd1b 100644
--- a/contrib/tzcode/asctime.c
+++ b/contrib/tzcode/asctime.c
@@ -1,108 +1,133 @@
 /* asctime and asctime_r a la POSIX and ISO C, except pad years before 1000.  */
 
 /*
 ** This file is in the public domain, so clarified as of
 ** 1996-06-05 by Arthur David Olson.
 */
 
 /*
 ** Avoid the temptation to punt entirely to strftime;
 ** the output of strftime is supposed to be locale specific
 ** whereas the output of asctime is supposed to be constant.
 */
 
 /*LINTLIBRARY*/
 
 #include "namespace.h"
 #include "private.h"
 #include "un-namespace.h"
 #include 
 
 /*
 ** All years associated with 32-bit time_t values are exactly four digits long;
 ** some years associated with 64-bit time_t values are not.
 ** Vintage programs are coded for years that are always four digits long
 ** and may assume that the newline always lands in the same place.
 ** For years that are less than four digits, we pad the output with
 ** leading zeroes to get the newline in the traditional place.
 ** The -4 ensures that we get four characters of output even if
 ** we call a strftime variant that produces fewer characters for some years.
 ** The ISO C and POSIX standards prohibit padding the year,
 ** but many implementations pad anyway; most likely the standards are buggy.
 */
 static char const ASCTIME_FMT[] = "%s %s%3d %.2d:%.2d:%.2d %-4s\n";
 /*
 ** For years that are more than four digits we put extra spaces before the year
 ** so that code trying to overwrite the newline won't end up overwriting
 ** a digit within a year and truncating the year (operating on the assumption
 ** that no output is better than wrong output).
 */
 static char const ASCTIME_FMT_B[] = "%s %s%3d %.2d:%.2d:%.2d     %s\n";
 
 enum { STD_ASCTIME_BUF_SIZE = 26 };
 /*
 ** Big enough for something such as
 ** ??? ???-2147483648 -2147483648:-2147483648:-2147483648     -2147483648\n
 ** (two three-character abbreviations, five strings denoting integers,
 ** seven explicit spaces, two explicit colons, a newline,
 ** and a trailing NUL byte).
 ** The values above are for systems where an int is 32 bits and are provided
 ** as an example; the size expression below is a bound for the system at
 ** hand.
 */
 static char buf_asctime[2*3 + 5*INT_STRLEN_MAXIMUM(int) + 7 + 2 + 1 + 1];
 
+/* A similar buffer for ctime.
+   C89 requires that they be the same buffer.
+   This requirement was removed in C99, so support it only if requested,
+   as support is more likely to lead to bugs in badly written programs.  */
+#if SUPPORT_C89
+# define buf_ctime buf_asctime
+#else
+static char buf_ctime[sizeof buf_asctime];
+#endif
+
 char *
-asctime_r(register const struct tm *timeptr, char *buf)
+asctime_r(struct tm const *restrict timeptr, char *restrict buf)
 {
 	static const char	wday_name[][4] = {
 		"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
 	};
 	static const char	mon_name[][4] = {
 		"Jan", "Feb", "Mar", "Apr", "May", "Jun",
 		"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
 	};
 	const char *	wn;
 	const char *	mn;
 	char			year[INT_STRLEN_MAXIMUM(int) + 2];
 	char result[sizeof buf_asctime];
 
 	if (timeptr == NULL) {
 		errno = EINVAL;
 		return strcpy(buf, "??? ??? ?? ??:??:?? ????\n");
 	}
 	if (timeptr->tm_wday < 0 || timeptr->tm_wday >= DAYSPERWEEK)
 		wn = "???";
 	else	wn = wday_name[timeptr->tm_wday];
 	if (timeptr->tm_mon < 0 || timeptr->tm_mon >= MONSPERYEAR)
 		mn = "???";
 	else	mn = mon_name[timeptr->tm_mon];
 	/*
 	** Use strftime's %Y to generate the year, to avoid overflow problems
 	** when computing timeptr->tm_year + TM_YEAR_BASE.
 	** Assume that strftime is unaffected by other out-of-range members
 	** (e.g., timeptr->tm_mday) when processing "%Y".
 	*/
 	strftime(year, sizeof year, "%Y", timeptr);
 	/*
 	** We avoid using snprintf since it's not available on all systems.
 	*/
 	sprintf(result,
 		((strlen(year) <= 4) ? ASCTIME_FMT : ASCTIME_FMT_B),
 		wn, mn,
 		timeptr->tm_mday, timeptr->tm_hour,
 		timeptr->tm_min, timeptr->tm_sec,
 		year);
-	if (strlen(result) < STD_ASCTIME_BUF_SIZE || buf == buf_asctime)
+	if (strlen(result) < STD_ASCTIME_BUF_SIZE
+	    || buf == buf_ctime || buf == buf_asctime)
 		return strcpy(buf, result);
 	else {
 		errno = EOVERFLOW;
 		return NULL;
 	}
 }
 
 char *
 asctime(register const struct tm *timeptr)
 {
 	return asctime_r(timeptr, buf_asctime);
 }
+
+char *
+ctime_r(const time_t *timep, char *buf)
+{
+  struct tm mytm;
+  struct tm *tmp = localtime_r(timep, &mytm);
+  return tmp ? asctime_r(tmp, buf) : NULL;
+}
+
+char *
+ctime(const time_t *timep)
+{
+  return ctime_r(timep, buf_ctime);
+}
diff --git a/contrib/tzcode/date.1 b/contrib/tzcode/date.1
index 043e568117df..e8107212364d 100644
--- a/contrib/tzcode/date.1
+++ b/contrib/tzcode/date.1
@@ -1,167 +1,168 @@
 .\" This file is in the public domain, so clarified as of
 .\" 2009-05-17 by Arthur David Olson.
-.TH date 1
+.TH date 1 "" "Time Zone Database"
 .SH NAME
 date \- show and set date and time
 .SH SYNOPSIS
 .if n .nh
 .if n .na
 .ie \n(.g .ds - \f(CR-\fP
 .el .ds - \-
 .B date
 [
 .B \*-u
 ] [
 .B \*-c
 ] [
 .B \*-r
 .I seconds
 ] [
 .BI + format
 ] [
 \fR[\fIyyyy\fR]\fImmddhhmm\fR[\fIyy\fR][\fB.\fIss\fR]
 ]
 .SH DESCRIPTION
 .ie '\(lq'' .ds lq \&"\"
 .el .ds lq \(lq\"
 .ie '\(rq'' .ds rq \&"\"
 .el .ds rq \(rq\"
 .de q
 \\$3\*(lq\\$1\*(rq\\$2
 ..
 The
 .B date
 command
 without arguments writes the date and time to the standard output in
 the form
 .ce 1
 Wed Mar  8 14:54:40 EST 1989
 .br
 with
 .B EST
 replaced by the local time zone's abbreviation
 (or by the abbreviation for the time zone specified in the
 .B TZ
 environment variable if set).
 The exact output format depends on the locale.
 .PP
 If a command-line argument starts with a plus sign (\c
 .q "\fB+\fP" ),
 the rest of the argument is used as a
 .I format
 that controls what appears in the output.
 In the format, when a percent sign (\c
 .q "\fB%\fP"
 appears,
 it and the character after it are not output,
 but rather identify part of the date or time
 to be output in a particular way
 (or identify a special character to output):
 .nf
 .sp
 .if t .in +.5i
 .if n .in +2
 .ta \w'%M\0\0'u +\w'Wed Mar  8 14:54:40 EST 1989\0\0'u
 	Sample output	Explanation
 %a	Wed	Abbreviated weekday name*
 %A	Wednesday	Full weekday name*
 %b	Mar	Abbreviated month name*
 %B	March	Full month name*
 %c	Wed Mar 08 14:54:40 1989	Date and time*
 %C	19	Century
 %d	08	Day of month (always two digits)
 %D	03/08/89	Month/day/year (eight characters)
 %e	 8	Day of month (leading zero blanked)
 %h	Mar	Abbreviated month name*
 %H	14	24-hour-clock hour (two digits)
 %I	02	12-hour-clock hour (two digits)
 %j	067	Julian day number (three digits)
 %k	 2	12-hour-clock hour (leading zero blanked)
 %l	14	24-hour-clock hour (leading zero blanked)
 %m	03	Month number (two digits)
 %M	54	Minute (two digits)
 %n	\\n	newline character
 %p	PM	AM/PM designation
 %r	02:54:40 PM	Hour:minute:second AM/PM designation
 %R	14:54	Hour:minute
 %S	40	Second (two digits)
 %t	\\t	tab character
 %T	14:54:40	Hour:minute:second
 %U	10	Sunday-based week number (two digits)
 %w	3	Day number (one digit, Sunday is 0)
 %W	10	Monday-based week number (two digits)
 %x	03/08/89	Date*
 %X	14:54:40	Time*
 %y	89	Last two digits of year
 %Y	1989	Year in full
 %z	-0500	Numeric time zone
 %Z	EST	Time zone abbreviation
 %+	Wed Mar  8 14:54:40 EST 1989	Default output format*
 .if t .in -.5i
 .if n .in -2
 * The exact output depends on the locale.
 .sp
 .fi
 If a character other than one of those shown above appears after
 a percent sign in the format,
 that following character is output.
 All other characters in the format are copied unchanged to the output;
 a newline character is always added at the end of the output.
 .PP
 In Sunday-based week numbering,
 the first Sunday of the year begins week 1;
 days preceding it are part of
 .q "week 0" .
 In Monday-based week numbering,
 the first Monday of the year begins week 1.
 .PP
 To set the date, use a command line argument with one of the following forms:
 .nf
 .if t .in +.5i
 .if n .in +2
 .ta \w'198903081454\0'u
 1454	24-hour-clock hours (first two digits) and minutes
 081454	Month day (first two digits), hours, and minutes
 03081454	Month (two digits, January is 01), month day, hours, minutes
 8903081454	Year, month, month day, hours, minutes
 0308145489	Month, month day, hours, minutes, year
 	(on System V-compatible systems)
 030814541989	Month, month day, hours, minutes, four-digit year
 198903081454	Four-digit year, month, month day, hours, minutes
 .if t .in -.5i
 .if n .in -2
 .fi
 If the century, year, month, or month day is not given,
 the current value is used.
 Any of the above forms may be followed by a period and two digits that give
 the seconds part of the new time; if no seconds are given, zero is assumed.
 .PP
 These options are available:
 .TP
 .BR \*-u " or " \*-c
 Use Universal Time when setting and showing the date and time.
 .TP
 .BI "\*-r " seconds
 Output the date that corresponds to
 .I seconds
 past the epoch of 1970-01-01 00:00:00 UTC, where
 .I seconds
 should be an integer, either decimal, octal (leading 0), or
 hexadecimal (leading 0x), preceded by an optional sign.
 .SH FILES
 .ta \w'/usr/share/zoneinfo/posixrules\0\0'u
 /etc/localtime	local timezone file
 .br
 /usr/lib/locale/\f2L\fP/LC_TIME	description of time locale \f2L\fP
 .br
 /usr/share/zoneinfo	timezone information directory
 .br
-/usr/share/zoneinfo/posixrules	used with POSIX-style TZ's
+/usr/share/zoneinfo/posixrules	default DST rules (obsolete,
+	and can cause bugs if present)
 .br
 /usr/share/zoneinfo/GMT	for UTC leap seconds
 .sp
 If
 .B /usr/share/zoneinfo/GMT
 is absent,
 UTC leap seconds are loaded from
 .BR /usr/share/zoneinfo/posixrules .
diff --git a/contrib/tzcode/date.c b/contrib/tzcode/date.c
index 11c5e5fe8d49..b62f04d768bc 100644
--- a/contrib/tzcode/date.c
+++ b/contrib/tzcode/date.c
@@ -1,216 +1,217 @@
 /* Display or set the current time and date.  */
 
 /* Copyright 1985, 1987, 1988 The Regents of the University of California.
    All rights reserved.
 
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions
    are met:
    1. Redistributions of source code must retain the above copyright
       notice, this list of conditions and the following disclaimer.
    2. Redistributions in binary form must reproduce the above copyright
       notice, this list of conditions and the following disclaimer in the
       documentation and/or other materials provided with the distribution.
    3. Neither the name of the University nor the names of its contributors
       may be used to endorse or promote products derived from this software
       without specific prior written permission.
 
    THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS" AND
    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
    ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
    OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
    SUCH DAMAGE.  */
 
 #include "private.h"
 #include 
 #include 
 
 #if !HAVE_POSIX_DECLS
 extern char *		optarg;
 extern int		optind;
 #endif
 
 static int		retval = EXIT_SUCCESS;
 
 static void		display(const char *, time_t);
 static void		dogmt(void);
 static void		errensure(void);
 static void		timeout(FILE *, const char *, const struct tm *);
-static ATTRIBUTE_NORETURN void usage(void);
+ATTRIBUTE_NORETURN static void usage(void);
 
 int
 main(const int argc, char *argv[])
 {
 	register const char *	format = "+%+";
 	register int		ch;
 	register bool		rflag = false;
 	time_t			t;
 	intmax_t		secs;
 	char *			endarg;
 
 #ifdef LC_ALL
 	setlocale(LC_ALL, "");
 #endif /* defined(LC_ALL) */
 #if HAVE_GETTEXT
 # ifdef TZ_DOMAINDIR
 	bindtextdomain(TZ_DOMAIN, TZ_DOMAINDIR);
 # endif /* defined(TEXTDOMAINDIR) */
 	textdomain(TZ_DOMAIN);
 #endif /* HAVE_GETTEXT */
 	t = time(NULL);
 	while ((ch = getopt(argc, argv, "ucr:")) != EOF && ch != -1) {
 		switch (ch) {
 		default:
 			usage();
 		case 'u':		/* do it in UT */
 		case 'c':
 			dogmt();
 			break;
 		case 'r':		/* seconds since 1970 */
 			if (rflag) {
 				fprintf(stderr,
 					_("date: error: multiple -r's used"));
 				usage();
 			}
 			rflag = true;
 			errno = 0;
 			secs = strtoimax(optarg, &endarg, 0);
 			if (*endarg || optarg == endarg)
 				errno = EINVAL;
 			else if (! (TIME_T_MIN <= secs && secs <= TIME_T_MAX))
 				errno = ERANGE;
 			if (errno) {
-				perror(optarg);
+				char const *e = strerror(errno);
+				fprintf(stderr, _("date: %s: %s\n"),
+					optarg, e);
 				errensure();
 				exit(retval);
 			}
 			t = secs;
 			break;
 		}
 	}
 	if (optind < argc) {
 	  if (argc - optind != 1) {
 	    fprintf(stderr,
 		    _("date: error: multiple operands in command line\n"));
 	    usage();
 	  }
 	  format = argv[optind];
 	  if (*format != '+') {
 	    fprintf(stderr, _("date: unknown operand: %s\n"), format);
 	    usage();
 	  }
 	}
 
 	display(format, t);
 	return retval;
 }
 
 static void
 dogmt(void)
 {
 	static char **	fakeenv;
 
 	if (fakeenv == NULL) {
 		static char	tzeutc0[] = "TZ=UTC0";
 		ptrdiff_t from, to, n;
 
 		for (n = 0;  environ[n] != NULL;  ++n)
 			continue;
 #if defined ckd_add && defined ckd_mul
 		if (!ckd_add(&n, n, 2) && !ckd_mul(&n, n, sizeof *fakeenv)
-		    && n <= SIZE_MAX)
+		    && n <= INDEX_MAX)
 		  fakeenv = malloc(n);
 #else
-		if (n <= min(PTRDIFF_MAX, SIZE_MAX) / sizeof *fakeenv - 2)
+		if (n <= INDEX_MAX / sizeof *fakeenv - 2)
 		  fakeenv = malloc((n + 2) * sizeof *fakeenv);
 #endif
 		if (fakeenv == NULL) {
 			fprintf(stderr, _("date: Memory exhausted\n"));
 			errensure();
 			exit(retval);
 		}
 		to = 0;
 		fakeenv[to++] = tzeutc0;
 		for (from = 1; environ[from] != NULL; ++from)
 			if (strncmp(environ[from], "TZ=", 3) != 0)
 				fakeenv[to++] = environ[from];
 		fakeenv[to] = NULL;
 		environ = fakeenv;
 	}
 }
 
 static void
 errensure(void)
 {
 	if (retval == EXIT_SUCCESS)
 		retval = EXIT_FAILURE;
 }
 
 static void
 usage(void)
 {
 	fprintf(stderr,
 		       _("date: usage: date [-u] [-c] [-r seconds]"
 			 " [+format]\n"));
 	errensure();
 	exit(retval);
 }
 
 static void
 display(char const *format, time_t now)
 {
 	struct tm *tmp;
 
 	tmp = localtime(&now);
 	if (!tmp) {
 		fprintf(stderr,
 			_("date: error: time out of range\n"));
 		errensure();
 		return;
 	}
 	timeout(stdout, format, tmp);
 	putchar('\n');
 	fflush(stdout);
 	fflush(stderr);
 	if (ferror(stdout) || ferror(stderr)) {
 		fprintf(stderr,
 			_("date: error: couldn't write results\n"));
 		errensure();
 	}
 }
 
 static void
 timeout(FILE *fp, char const *format, struct tm const *tmp)
 {
 	char *cp = NULL;
 	ptrdiff_t result;
 	ptrdiff_t size = 1024 / 2;
 
 	for ( ; ; ) {
 #ifdef ckd_mul
-		bool bigger = !ckd_mul(&size, size, 2) && size <= SIZE_MAX;
+		bool bigger = !ckd_mul(&size, size, 2) && size <= INDEX_MAX;
 #else
-		bool bigger = (size <= min(PTRDIFF_MAX, SIZE_MAX) / 2
-			       && (size *= 2, true));
+		bool bigger = size <= INDEX_MAX / 2 && (size *= 2, true);
 #endif
 		char *newcp = bigger ? realloc(cp, size) : NULL;
 		if (!newcp) {
 			fprintf(stderr,
 				_("date: error: can't get memory\n"));
 			errensure();
 			exit(retval);
 		}
 		cp = newcp;
 		result = strftime(cp, size, format, tmp);
 		if (result != 0)
 			break;
 	}
 	fwrite(cp + 1, 1, result - 1, fp);
 	free(cp);
 }
diff --git a/contrib/tzcode/localtime.c b/contrib/tzcode/localtime.c
index a8beaf47319a..3bf9378fe673 100644
--- a/contrib/tzcode/localtime.c
+++ b/contrib/tzcode/localtime.c
@@ -1,2671 +1,2691 @@
 /* Convert timestamp from time_t to struct tm.  */
 
 /*
 ** This file is in the public domain, so clarified as of
 ** 1996-06-05 by Arthur David Olson.
 */
 
 /*
 ** Leap second handling from Bradley White.
 ** POSIX-style TZ environment variable handling from Guy Harris.
 */
 
 /*LINTLIBRARY*/
 
 #define LOCALTIME_IMPLEMENTATION
 #include "namespace.h"
 #ifdef DETECT_TZ_CHANGES
 #ifndef DETECT_TZ_CHANGES_INTERVAL
 #define DETECT_TZ_CHANGES_INTERVAL 61
 #endif
 #include 
 #endif
 #include 
 #if THREAD_SAFE
 #include 
 #endif
 #include "private.h"
 #include "un-namespace.h"
 
 #include "tzfile.h"
 
 #include "libc_private.h"
 
 #if defined THREAD_SAFE && THREAD_SAFE
 static pthread_mutex_t locallock = PTHREAD_MUTEX_INITIALIZER;
 static int lock(void) {
 	if (__isthreaded)
 		return _pthread_mutex_lock(&locallock);
 	return 0;
 }
 static void unlock(void) {
 	if (__isthreaded)
 		_pthread_mutex_unlock(&locallock);
 }
 #else
 static int lock(void) { return 0; }
 static void unlock(void) { }
 #endif
 
-#ifndef TZ_ABBR_MAX_LEN
-# define TZ_ABBR_MAX_LEN 16
-#endif /* !defined TZ_ABBR_MAX_LEN */
-
 #ifndef TZ_ABBR_CHAR_SET
 # define TZ_ABBR_CHAR_SET \
 	"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 :+-._"
 #endif /* !defined TZ_ABBR_CHAR_SET */
 
 #ifndef TZ_ABBR_ERR_CHAR
 # define TZ_ABBR_ERR_CHAR '_'
 #endif /* !defined TZ_ABBR_ERR_CHAR */
 
 /*
 ** Support non-POSIX platforms that distinguish between text and binary files.
 */
 
 #ifndef O_BINARY
 # define O_BINARY 0
 #endif
 
 #ifndef WILDABBR
 /*
 ** Someone might make incorrect use of a time zone abbreviation:
 **	1.	They might reference tzname[0] before calling tzset (explicitly
 **		or implicitly).
 **	2.	They might reference tzname[1] before calling tzset (explicitly
 **		or implicitly).
 **	3.	They might reference tzname[1] after setting to a time zone
 **		in which Daylight Saving Time is never observed.
 **	4.	They might reference tzname[0] after setting to a time zone
 **		in which Standard Time is never observed.
 **	5.	They might reference tm.TM_ZONE after calling offtime.
 ** What's best to do in the above cases is open to debate;
 ** for now, we just set things up so that in any of the five cases
 ** WILDABBR is used. Another possibility: initialize tzname[0] to the
 ** string "tzname[0] used before set", and similarly for the other cases.
 ** And another: initialize tzname[0] to "ERA", with an explanation in the
 ** manual page of what this "time zone abbreviation" means (doing this so
 ** that tzname[0] has the "normal" length of three characters).
 */
 # define WILDABBR "   "
 #endif /* !defined WILDABBR */
 
 static const char	wildabbr[] = WILDABBR;
 
 static char const etc_utc[] = "Etc/UTC";
 static char const *utc = etc_utc + sizeof "Etc/" - 1;
 
 /*
 ** The DST rules to use if TZ has no rules and we can't load TZDEFRULES.
 ** Default to US rules as of 2017-05-07.
 ** POSIX does not specify the default DST rules;
 ** for historical reasons, US rules are a common default.
 */
 #ifndef TZDEFRULESTRING
 # define TZDEFRULESTRING ",M3.2.0,M11.1.0"
 #endif
 
 struct ttinfo {				/* time type information */
 	int_fast32_t	tt_utoff;	/* UT offset in seconds */
 	bool		tt_isdst;	/* used to set tm_isdst */
 	int		tt_desigidx;	/* abbreviation list index */
 	bool		tt_ttisstd;	/* transition is std time */
 	bool		tt_ttisut;	/* transition is UT */
 };
 
 struct lsinfo {				/* leap second information */
 	time_t		ls_trans;	/* transition time */
 	int_fast32_t	ls_corr;	/* correction to apply */
 };
 
 /* This abbreviation means local time is unspecified.  */
 static char const UNSPEC[] = "-00";
 
 /* How many extra bytes are needed at the end of struct state's chars array.
    This needs to be at least 1 for null termination in case the input
    data isn't properly terminated, and it also needs to be big enough
    for ttunspecified to work without crashing.  */
 enum { CHARS_EXTRA = max(sizeof UNSPEC, 2) - 1 };
 
-#ifdef TZNAME_MAX
-# define MY_TZNAME_MAX TZNAME_MAX
-#endif /* defined TZNAME_MAX */
-#ifndef TZNAME_MAX
-# define MY_TZNAME_MAX 255
-#endif /* !defined TZNAME_MAX */
+/* Limit to time zone abbreviation length in POSIX-style TZ strings.
+   This is distinct from TZ_MAX_CHARS, which limits TZif file contents.  */
+#ifndef TZNAME_MAXIMUM
+# define TZNAME_MAXIMUM 255
+#endif
 
 struct state {
 	int		leapcnt;
 	int		timecnt;
 	int		typecnt;
 	int		charcnt;
 	bool		goback;
 	bool		goahead;
 	time_t		ats[TZ_MAX_TIMES];
 	unsigned char	types[TZ_MAX_TIMES];
 	struct ttinfo	ttis[TZ_MAX_TYPES];
 	char chars[max(max(TZ_MAX_CHARS + CHARS_EXTRA, sizeof "UTC"),
-		       2 * (MY_TZNAME_MAX + 1))];
+		       2 * (TZNAME_MAXIMUM + 1))];
 	struct lsinfo	lsis[TZ_MAX_LEAPS];
 
 	/* The time type to use for early times or if no transitions.
 	   It is always zero for recent tzdb releases.
 	   It might be nonzero for data from tzdb 2018e or earlier.  */
 	int defaulttype;
 };
 
 enum r_type {
   JULIAN_DAY,		/* Jn = Julian day */
   DAY_OF_YEAR,		/* n = day of year */
   MONTH_NTH_DAY_OF_WEEK	/* Mm.n.d = month, week, day of week */
 };
 
 struct rule {
 	enum r_type	r_type;		/* type of rule */
 	int		r_day;		/* day number of rule */
 	int		r_week;		/* week number of rule */
 	int		r_mon;		/* month number of rule */
 	int_fast32_t	r_time;		/* transition time of rule */
 };
 
 static struct tm *gmtsub(struct state const *, time_t const *, int_fast32_t,
 			 struct tm *);
 static bool increment_overflow(int *, int);
 static bool increment_overflow_time(time_t *, int_fast32_t);
 static int_fast32_t leapcorr(struct state const *, time_t);
 static bool normalize_overflow32(int_fast32_t *, int *, int);
 static struct tm *timesub(time_t const *, int_fast32_t, struct state const *,
 			  struct tm *);
 static bool typesequiv(struct state const *, int, int);
 static bool tzparse(char const *, struct state *, struct state *);
 
 #ifdef ALL_STATE
 static struct state *	lclptr;
 static struct state *	gmtptr;
 #endif /* defined ALL_STATE */
 
 #ifndef ALL_STATE
 static struct state	lclmem;
 static struct state	gmtmem;
 static struct state *const lclptr = &lclmem;
 static struct state *const gmtptr = &gmtmem;
 #endif /* State Farm */
 
 #ifndef TZ_STRLEN_MAX
 # define TZ_STRLEN_MAX 255
 #endif /* !defined TZ_STRLEN_MAX */
 
 static char		lcl_TZname[TZ_STRLEN_MAX + 1];
 static int		lcl_is_set;
 
 static pthread_once_t	gmt_once = PTHREAD_ONCE_INIT;
 static pthread_once_t	gmtime_once = PTHREAD_ONCE_INIT;
 static pthread_key_t	gmtime_key;
 static int		gmtime_key_error;
+static pthread_once_t	offtime_once = PTHREAD_ONCE_INIT;
+static pthread_key_t	offtime_key;
+static int		offtime_key_error;
 static pthread_once_t	localtime_once = PTHREAD_ONCE_INIT;
 static pthread_key_t	localtime_key;
 static int		localtime_key_error;
 
 /*
 ** Section 4.12.3 of X3.159-1989 requires that
 **	Except for the strftime function, these functions [asctime,
 **	ctime, gmtime, localtime] return values in one of two static
 **	objects: a broken-down time structure and an array of char.
 ** Thanks to Paul Eggert for noting this.
+**
+** This requirement was removed in C99, so support it only if requested,
+** as support is more likely to lead to bugs in badly written programs.
 */
 
+#if SUPPORT_C89
 static struct tm	tm;
+#endif
 
 #if 2 <= HAVE_TZNAME + TZ_TIME_T
 char *			tzname[2] = {
 	(char *) wildabbr,
 	(char *) wildabbr
 };
 #endif
 #if 2 <= USG_COMPAT + TZ_TIME_T
 long			timezone;
 int			daylight;
 #endif
 #if 2 <= ALTZONE + TZ_TIME_T
 long			altzone;
 #endif
 
 /* Initialize *S to a value based on UTOFF, ISDST, and DESIGIDX.  */
 static void
 init_ttinfo(struct ttinfo *s, int_fast32_t utoff, bool isdst, int desigidx)
 {
   s->tt_utoff = utoff;
   s->tt_isdst = isdst;
   s->tt_desigidx = desigidx;
   s->tt_ttisstd = false;
   s->tt_ttisut = false;
 }
 
 /* Return true if SP's time type I does not specify local time.  */
 static bool
 ttunspecified(struct state const *sp, int i)
 {
   char const *abbr = &sp->chars[sp->ttis[i].tt_desigidx];
   /* memcmp is likely faster than strcmp, and is safe due to CHARS_EXTRA.  */
   return memcmp(abbr, UNSPEC, sizeof UNSPEC) == 0;
 }
 
 static int_fast32_t
 detzcode(const char *const codep)
 {
 	register int_fast32_t	result;
 	register int		i;
 	int_fast32_t one = 1;
 	int_fast32_t halfmaxval = one << (32 - 2);
 	int_fast32_t maxval = halfmaxval - 1 + halfmaxval;
 	int_fast32_t minval = -1 - maxval;
 
 	result = codep[0] & 0x7f;
 	for (i = 1; i < 4; ++i)
 		result = (result << 8) | (codep[i] & 0xff);
 
 	if (codep[0] & 0x80) {
 	  /* Do two's-complement negation even on non-two's-complement machines.
 	     If the result would be minval - 1, return minval.  */
 	  result -= !TWOS_COMPLEMENT(int_fast32_t) && result != 0;
 	  result += minval;
 	}
 	return result;
 }
 
 static int_fast64_t
 detzcode64(const char *const codep)
 {
 	register int_fast64_t result;
 	register int	i;
 	int_fast64_t one = 1;
 	int_fast64_t halfmaxval = one << (64 - 2);
 	int_fast64_t maxval = halfmaxval - 1 + halfmaxval;
 	int_fast64_t minval = -TWOS_COMPLEMENT(int_fast64_t) - maxval;
 
 	result = codep[0] & 0x7f;
 	for (i = 1; i < 8; ++i)
 		result = (result << 8) | (codep[i] & 0xff);
 
 	if (codep[0] & 0x80) {
 	  /* Do two's-complement negation even on non-two's-complement machines.
 	     If the result would be minval - 1, return minval.  */
 	  result -= !TWOS_COMPLEMENT(int_fast64_t) && result != 0;
 	  result += minval;
 	}
 	return result;
 }
 
 static void
 update_tzname_etc(struct state const *sp, struct ttinfo const *ttisp)
 {
 #if HAVE_TZNAME
   tzname[ttisp->tt_isdst] = (char *) &sp->chars[ttisp->tt_desigidx];
 #endif
 #if USG_COMPAT
   if (!ttisp->tt_isdst)
     timezone = - ttisp->tt_utoff;
 #endif
 #if ALTZONE
   if (ttisp->tt_isdst)
     altzone = - ttisp->tt_utoff;
 #endif
 }
 
 /* If STDDST_MASK indicates that SP's TYPE provides useful info,
    update tzname, timezone, and/or altzone and return STDDST_MASK,
    diminished by the provided info if it is a specified local time.
    Otherwise, return STDDST_MASK.  See settzname for STDDST_MASK.  */
 static int
 may_update_tzname_etc(int stddst_mask, struct state *sp, int type)
 {
   struct ttinfo *ttisp = &sp->ttis[type];
   int this_bit = 1 << ttisp->tt_isdst;
   if (stddst_mask & this_bit) {
     update_tzname_etc(sp, ttisp);
     if (!ttunspecified(sp, type))
       return stddst_mask & ~this_bit;
   }
   return stddst_mask;
 }
 
 static void
 settzname(void)
 {
 	register struct state * const	sp = lclptr;
 	register int			i;
 
 	/* If STDDST_MASK & 1 we need info about a standard time.
 	   If STDDST_MASK & 2 we need info about a daylight saving time.
 	   When STDDST_MASK becomes zero we can stop looking.  */
 	int stddst_mask = 0;
 
 #if HAVE_TZNAME
 	tzname[0] = tzname[1] = (char *) (sp ? wildabbr : utc);
 	stddst_mask = 3;
 #endif
 #if USG_COMPAT
 	timezone = 0;
 	stddst_mask = 3;
 #endif
 #if ALTZONE
 	altzone = 0;
 	stddst_mask |= 2;
 #endif
 	/*
 	** And to get the latest time zone abbreviations into tzname. . .
 	*/
 	if (sp) {
 	  for (i = sp->timecnt - 1; stddst_mask && 0 <= i; i--)
 	    stddst_mask = may_update_tzname_etc(stddst_mask, sp, sp->types[i]);
 	  for (i = sp->typecnt - 1; stddst_mask && 0 <= i; i--)
 	    stddst_mask = may_update_tzname_etc(stddst_mask, sp, i);
 	}
 #if USG_COMPAT
 	daylight = stddst_mask >> 1 ^ 1;
 #endif
 }
 
-static void
+/* Replace bogus characters in time zone abbreviations.
+   Return 0 on success, an errno value if a time zone abbreviation is
+   too long.  */
+static int
 scrub_abbrs(struct state *sp)
 {
 	int i;
-	/*
-	** First, replace bogus characters.
-	*/
+
+	/* Reject overlong abbreviations.  */
+	for (i = 0; i < sp->charcnt - (TZNAME_MAXIMUM + 1); ) {
+	  int len = strlen(&sp->chars[i]);
+	  if (TZNAME_MAXIMUM < len)
+	    return EOVERFLOW;
+	  i += len + 1;
+	}
+
+	/* Replace bogus characters.  */
 	for (i = 0; i < sp->charcnt; ++i)
 		if (strchr(TZ_ABBR_CHAR_SET, sp->chars[i]) == NULL)
 			sp->chars[i] = TZ_ABBR_ERR_CHAR;
-	/*
-	** Second, truncate long abbreviations.
-	*/
-	for (i = 0; i < sp->typecnt; ++i) {
-		register const struct ttinfo * const	ttisp = &sp->ttis[i];
-		char *cp = &sp->chars[ttisp->tt_desigidx];
 
-		if (strlen(cp) > TZ_ABBR_MAX_LEN &&
-			strcmp(cp, GRANDPARENTED) != 0)
-				*(cp + TZ_ABBR_MAX_LEN) = '\0';
-	}
+	return 0;
 }
 
 #ifdef DETECT_TZ_CHANGES
 /*
  * Determine if there's a change in the timezone since the last time we checked.
  * Returns: -1 on error
  * 	     0 if the timezone has not changed
  *	     1 if the timezone has changed
  */
 static int
 change_in_tz(const char *name)
 {
 	static char old_name[PATH_MAX];
 	static struct stat old_sb;
 	struct stat sb;
 	int error;
 
 	error = stat(name, &sb);
 	if (error != 0)
 		return -1;
 
 	if (strcmp(name, old_name) != 0) {
 		strlcpy(old_name, name, sizeof(old_name));
 		old_sb = sb;
 		return 1;
 	}
 
 	if (sb.st_dev != old_sb.st_dev ||
 	    sb.st_ino != old_sb.st_ino ||
 	    sb.st_ctime != old_sb.st_ctime ||
 	    sb.st_mtime != old_sb.st_mtime) {
 		old_sb = sb;
 		return 1;
 	}
 
 	return 0;
 }
 #else /* !DETECT_TZ_CHANGES */
 #define	change_in_tz(X)	1
 #endif /* !DETECT_TZ_CHANGES */
 
 /* Input buffer for data read from a compiled tz file.  */
 union input_buffer {
   /* The first part of the buffer, interpreted as a header.  */
   struct tzhead tzhead;
 
   /* The entire buffer.  */
   char buf[2 * sizeof(struct tzhead) + 2 * sizeof(struct state)
 	   + 4 * TZ_MAX_TIMES];
 };
 
 /* TZDIR with a trailing '/' rather than a trailing '\0'.  */
 static char const tzdirslash[sizeof TZDIR] = TZDIR "/";
 
 /* Local storage needed for 'tzloadbody'.  */
 union local_storage {
   /* The results of analyzing the file's contents after it is opened.  */
   struct file_analysis {
     /* The input buffer.  */
     union input_buffer u;
 
     /* A temporary state used for parsing a TZ string in the file.  */
     struct state st;
   } u;
 
   /* The file name to be opened.  */
   char fullname[max(sizeof(struct file_analysis), sizeof tzdirslash + 1024)];
 };
 
 /* Load tz data from the file named NAME into *SP.  Read extended
    format if DOEXTEND.  Use *LSP for temporary storage.  Return 0 on
    success, an errno value on failure.  */
 static int
 tzloadbody(char const *name, struct state *sp, bool doextend,
 	   union local_storage *lsp)
 {
 	register int			i;
 	register int			fid;
 	register int			stored;
 	register ssize_t		nread;
 	register union input_buffer *up = &lsp->u.u;
 	register int tzheadsize = sizeof(struct tzhead);
 
 	sp->goback = sp->goahead = false;
 
 	if (! name) {
 		name = TZDEFAULT;
 		if (! name)
 		  return EINVAL;
 	}
 
 	if (name[0] == ':')
 		++name;
 	if (name[0] != '/') {
 		if (sizeof lsp->fullname - sizeof tzdirslash <= strlen(name))
 		  return ENAMETOOLONG;
 
 		/* Create a string "TZDIR/NAME".  Using sprintf here
 		   would pull in stdio (and would fail if the
 		   resulting string length exceeded INT_MAX!).  */
 		memcpy(lsp->fullname, tzdirslash, sizeof tzdirslash);
 		strcpy(lsp->fullname + sizeof tzdirslash, name);
 
 		name = lsp->fullname;
 	}
 	if (doextend) {
 		/*
 		 * Detect if the timezone file has changed.  Check
 		 * 'doextend' to ignore TZDEFRULES; the change_in_tz()
 		 * function can only keep state for a single file.
 		 */
 		int ret = change_in_tz(name);
 		if (ret <= 0) {
 			/*
 			 * Returns an errno value if there was an error,
 			 * and 0 if the timezone had not changed.
 			 */
 			return errno;
 		}
 	}
 	fid = _open(name, O_RDONLY | O_BINARY);
 	if (fid < 0)
 	  return errno;
 
 	nread = _read(fid, up->buf, sizeof up->buf);
 	if (nread < tzheadsize) {
 	  int err = nread < 0 ? errno : EINVAL;
 	  _close(fid);
 	  return err;
 	}
 	if (_close(fid) < 0)
 	  return errno;
 	for (stored = 4; stored <= 8; stored *= 2) {
 	    char version = up->tzhead.tzh_version[0];
 	    bool skip_datablock = stored == 4 && version;
 	    int_fast32_t datablock_size;
 	    int_fast32_t ttisstdcnt = detzcode(up->tzhead.tzh_ttisstdcnt);
 	    int_fast32_t ttisutcnt = detzcode(up->tzhead.tzh_ttisutcnt);
 	    int_fast64_t prevtr = -1;
 	    int_fast32_t prevcorr;
 	    int_fast32_t leapcnt = detzcode(up->tzhead.tzh_leapcnt);
 	    int_fast32_t timecnt = detzcode(up->tzhead.tzh_timecnt);
 	    int_fast32_t typecnt = detzcode(up->tzhead.tzh_typecnt);
 	    int_fast32_t charcnt = detzcode(up->tzhead.tzh_charcnt);
 	    char const *p = up->buf + tzheadsize;
 	    /* Although tzfile(5) currently requires typecnt to be nonzero,
 	       support future formats that may allow zero typecnt
 	       in files that have a TZ string and no transitions.  */
 	    if (! (0 <= leapcnt && leapcnt < TZ_MAX_LEAPS
 		   && 0 <= typecnt && typecnt < TZ_MAX_TYPES
 		   && 0 <= timecnt && timecnt < TZ_MAX_TIMES
 		   && 0 <= charcnt && charcnt < TZ_MAX_CHARS
 		   && 0 <= ttisstdcnt && ttisstdcnt < TZ_MAX_TYPES
 		   && 0 <= ttisutcnt && ttisutcnt < TZ_MAX_TYPES))
 	      return EINVAL;
 	    datablock_size
 		    = (timecnt * stored		/* ats */
 		       + timecnt		/* types */
 		       + typecnt * 6		/* ttinfos */
 		       + charcnt		/* chars */
 		       + leapcnt * (stored + 4)	/* lsinfos */
 		       + ttisstdcnt		/* ttisstds */
 		       + ttisutcnt);		/* ttisuts */
 	    if (nread < tzheadsize + datablock_size)
 	      return EINVAL;
 	    if (skip_datablock)
 		p += datablock_size;
 	    else {
 		if (! ((ttisstdcnt == typecnt || ttisstdcnt == 0)
 		       && (ttisutcnt == typecnt || ttisutcnt == 0)))
 		  return EINVAL;
 
 		sp->leapcnt = leapcnt;
 		sp->timecnt = timecnt;
 		sp->typecnt = typecnt;
 		sp->charcnt = charcnt;
 
 		/* Read transitions, discarding those out of time_t range.
 		   But pretend the last transition before TIME_T_MIN
 		   occurred at TIME_T_MIN.  */
 		timecnt = 0;
 		for (i = 0; i < sp->timecnt; ++i) {
 			int_fast64_t at
 			  = stored == 4 ? detzcode(p) : detzcode64(p);
 			sp->types[i] = at <= TIME_T_MAX;
 			if (sp->types[i]) {
 			  time_t attime
 			    = ((TYPE_SIGNED(time_t) ? at < TIME_T_MIN : at < 0)
 			       ? TIME_T_MIN : at);
 			  if (timecnt && attime <= sp->ats[timecnt - 1]) {
 			    if (attime < sp->ats[timecnt - 1])
 			      return EINVAL;
 			    sp->types[i - 1] = 0;
 			    timecnt--;
 			  }
 			  sp->ats[timecnt++] = attime;
 			}
 			p += stored;
 		}
 
 		timecnt = 0;
 		for (i = 0; i < sp->timecnt; ++i) {
 			unsigned char typ = *p++;
 			if (sp->typecnt <= typ)
 			  return EINVAL;
 			if (sp->types[i])
 				sp->types[timecnt++] = typ;
 		}
 		sp->timecnt = timecnt;
 		for (i = 0; i < sp->typecnt; ++i) {
 			register struct ttinfo *	ttisp;
 			unsigned char isdst, desigidx;
 
 			ttisp = &sp->ttis[i];
 			ttisp->tt_utoff = detzcode(p);
 			p += 4;
 			isdst = *p++;
 			if (! (isdst < 2))
 			  return EINVAL;
 			ttisp->tt_isdst = isdst;
 			desigidx = *p++;
 			if (! (desigidx < sp->charcnt))
 			  return EINVAL;
 			ttisp->tt_desigidx = desigidx;
 		}
 		for (i = 0; i < sp->charcnt; ++i)
 			sp->chars[i] = *p++;
 		/* Ensure '\0'-terminated, and make it safe to call
 		   ttunspecified later.  */
 		memset(&sp->chars[i], 0, CHARS_EXTRA);
 
 		/* Read leap seconds, discarding those out of time_t range.  */
 		leapcnt = 0;
 		for (i = 0; i < sp->leapcnt; ++i) {
 		  int_fast64_t tr = stored == 4 ? detzcode(p) : detzcode64(p);
 		  int_fast32_t corr = detzcode(p + stored);
 		  p += stored + 4;
 
 		  /* Leap seconds cannot occur before the Epoch,
 		     or out of order.  */
 		  if (tr <= prevtr)
 		    return EINVAL;
 
 		  /* To avoid other botches in this code, each leap second's
 		     correction must differ from the previous one's by 1
 		     second or less, except that the first correction can be
 		     any value; these requirements are more generous than
 		     RFC 8536, to allow future RFC extensions.  */
 		  if (! (i == 0
 			 || (prevcorr < corr
 			     ? corr == prevcorr + 1
 			     : (corr == prevcorr
 				|| corr == prevcorr - 1))))
 		    return EINVAL;
 		  prevtr = tr;
 		  prevcorr = corr;
 
 		  if (tr <= TIME_T_MAX) {
 		    sp->lsis[leapcnt].ls_trans = tr;
 		    sp->lsis[leapcnt].ls_corr = corr;
 		    leapcnt++;
 		  }
 		}
 		sp->leapcnt = leapcnt;
 
 		for (i = 0; i < sp->typecnt; ++i) {
 			register struct ttinfo *	ttisp;
 
 			ttisp = &sp->ttis[i];
 			if (ttisstdcnt == 0)
 				ttisp->tt_ttisstd = false;
 			else {
 				if (*p != true && *p != false)
 				  return EINVAL;
 				ttisp->tt_ttisstd = *p++;
 			}
 		}
 		for (i = 0; i < sp->typecnt; ++i) {
 			register struct ttinfo *	ttisp;
 
 			ttisp = &sp->ttis[i];
 			if (ttisutcnt == 0)
 				ttisp->tt_ttisut = false;
 			else {
 				if (*p != true && *p != false)
 						return EINVAL;
 				ttisp->tt_ttisut = *p++;
 			}
 		}
 	    }
 
 	    nread -= p - up->buf;
 	    memmove(up->buf, p, nread);
 
 	    /* If this is an old file, we're done.  */
 	    if (!version)
 	      break;
 	}
 	if (doextend && nread > 2 &&
 		up->buf[0] == '\n' && up->buf[nread - 1] == '\n' &&
 		sp->typecnt + 2 <= TZ_MAX_TYPES) {
 			struct state	*ts = &lsp->u.st;
 
 			up->buf[nread - 1] = '\0';
 			if (tzparse(&up->buf[1], ts, sp)) {
 
 			  /* Attempt to reuse existing abbreviations.
 			     Without this, America/Anchorage would be right on
 			     the edge after 2037 when TZ_MAX_CHARS is 50, as
 			     sp->charcnt equals 40 (for LMT AST AWT APT AHST
 			     AHDT YST AKDT AKST) and ts->charcnt equals 10
 			     (for AKST AKDT).  Reusing means sp->charcnt can
 			     stay 40 in this example.  */
 			  int gotabbr = 0;
 			  int charcnt = sp->charcnt;
 			  for (i = 0; i < ts->typecnt; i++) {
 			    char *tsabbr = ts->chars + ts->ttis[i].tt_desigidx;
 			    int j;
 			    for (j = 0; j < charcnt; j++)
 			      if (strcmp(sp->chars + j, tsabbr) == 0) {
 				ts->ttis[i].tt_desigidx = j;
 				gotabbr++;
 				break;
 			      }
 			    if (! (j < charcnt)) {
 			      int tsabbrlen = strlen(tsabbr);
 			      if (j + tsabbrlen < TZ_MAX_CHARS) {
 				strcpy(sp->chars + j, tsabbr);
 				charcnt = j + tsabbrlen + 1;
 				ts->ttis[i].tt_desigidx = j;
 				gotabbr++;
 			      }
 			    }
 			  }
 			  if (gotabbr == ts->typecnt) {
 			    sp->charcnt = charcnt;
 
 			    /* Ignore any trailing, no-op transitions generated
 			       by zic as they don't help here and can run afoul
 			       of bugs in zic 2016j or earlier.  */
 			    while (1 < sp->timecnt
 				   && (sp->types[sp->timecnt - 1]
 				       == sp->types[sp->timecnt - 2]))
 			      sp->timecnt--;
 
 			    for (i = 0;
 				 i < ts->timecnt && sp->timecnt < TZ_MAX_TIMES;
 				 i++) {
 			      time_t t = ts->ats[i];
 			      if (increment_overflow_time(&t, leapcorr(sp, t))
 				  || (0 < sp->timecnt
 				      && t <= sp->ats[sp->timecnt - 1]))
 				continue;
 			      sp->ats[sp->timecnt] = t;
 			      sp->types[sp->timecnt] = (sp->typecnt
 							+ ts->types[i]);
 			      sp->timecnt++;
 			    }
 			    for (i = 0; i < ts->typecnt; i++)
 			      sp->ttis[sp->typecnt++] = ts->ttis[i];
 			  }
 			}
 	}
 	if (sp->typecnt == 0)
 	  return EINVAL;
 	if (sp->timecnt > 1) {
 	    if (sp->ats[0] <= TIME_T_MAX - SECSPERREPEAT) {
 		time_t repeatat = sp->ats[0] + SECSPERREPEAT;
 		int repeattype = sp->types[0];
 		for (i = 1; i < sp->timecnt; ++i)
 		  if (sp->ats[i] == repeatat
 		      && typesequiv(sp, sp->types[i], repeattype)) {
 					sp->goback = true;
 					break;
 		  }
 	    }
 	    if (TIME_T_MIN + SECSPERREPEAT <= sp->ats[sp->timecnt - 1]) {
 		time_t repeatat = sp->ats[sp->timecnt - 1] - SECSPERREPEAT;
 		int repeattype = sp->types[sp->timecnt - 1];
 		for (i = sp->timecnt - 2; i >= 0; --i)
 		  if (sp->ats[i] == repeatat
 		      && typesequiv(sp, sp->types[i], repeattype)) {
 					sp->goahead = true;
 					break;
 		  }
 	    }
 	}
 
 	/* Infer sp->defaulttype from the data.  Although this default
 	   type is always zero for data from recent tzdb releases,
 	   things are trickier for data from tzdb 2018e or earlier.
 
 	   The first set of heuristics work around bugs in 32-bit data
 	   generated by tzdb 2013c or earlier.  The workaround is for
 	   zones like Australia/Macquarie where timestamps before the
 	   first transition have a time type that is not the earliest
 	   standard-time type.  See:
 	   https://mm.icann.org/pipermail/tz/2013-May/019368.html */
 	/*
 	** If type 0 does not specify local time, or is unused in transitions,
 	** it's the type to use for early times.
 	*/
 	for (i = 0; i < sp->timecnt; ++i)
 		if (sp->types[i] == 0)
 			break;
 	i = i < sp->timecnt && ! ttunspecified(sp, 0) ? -1 : 0;
 	/*
 	** Absent the above,
 	** if there are transition times
 	** and the first transition is to a daylight time
 	** find the standard type less than and closest to
 	** the type of the first transition.
 	*/
 	if (i < 0 && sp->timecnt > 0 && sp->ttis[sp->types[0]].tt_isdst) {
 		i = sp->types[0];
 		while (--i >= 0)
 			if (!sp->ttis[i].tt_isdst)
 				break;
 	}
 	/* The next heuristics are for data generated by tzdb 2018e or
 	   earlier, for zones like EST5EDT where the first transition
 	   is to DST.  */
 	/*
 	** If no result yet, find the first standard type.
 	** If there is none, punt to type zero.
 	*/
 	if (i < 0) {
 		i = 0;
 		while (sp->ttis[i].tt_isdst)
 			if (++i >= sp->typecnt) {
 				i = 0;
 				break;
 			}
 	}
 	/* A simple 'sp->defaulttype = 0;' would suffice here if we
 	   didn't have to worry about 2018e-or-earlier data.  Even
 	   simpler would be to remove the defaulttype member and just
 	   use 0 in its place.  */
 	sp->defaulttype = i;
 
 	return 0;
 }
 
 /* Load tz data from the file named NAME into *SP.  Read extended
    format if DOEXTEND.  Return 0 on success, an errno value on failure.  */
 static int
 tzload(char const *name, struct state *sp, bool doextend)
 {
 #ifdef ALL_STATE
   union local_storage *lsp = malloc(sizeof *lsp);
   if (!lsp) {
     return HAVE_MALLOC_ERRNO ? errno : ENOMEM;
   } else {
     int err = tzloadbody(name, sp, doextend, lsp);
     free(lsp);
     return err;
   }
 #else
   union local_storage ls;
   return tzloadbody(name, sp, doextend, &ls);
 #endif
 }
 
 static bool
 typesequiv(const struct state *sp, int a, int b)
 {
 	register bool result;
 
 	if (sp == NULL ||
 		a < 0 || a >= sp->typecnt ||
 		b < 0 || b >= sp->typecnt)
 			result = false;
 	else {
 		/* Compare the relevant members of *AP and *BP.
 		   Ignore tt_ttisstd and tt_ttisut, as they are
 		   irrelevant now and counting them could cause
 		   sp->goahead to mistakenly remain false.  */
 		register const struct ttinfo *	ap = &sp->ttis[a];
 		register const struct ttinfo *	bp = &sp->ttis[b];
 		result = (ap->tt_utoff == bp->tt_utoff
 			  && ap->tt_isdst == bp->tt_isdst
 			  && (strcmp(&sp->chars[ap->tt_desigidx],
 				     &sp->chars[bp->tt_desigidx])
 			      == 0));
 	}
 	return result;
 }
 
 static const int	mon_lengths[2][MONSPERYEAR] = {
 	{ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
 	{ 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
 };
 
 static const int	year_lengths[2] = {
 	DAYSPERNYEAR, DAYSPERLYEAR
 };
 
 /* Is C an ASCII digit?  */
 static bool
 is_digit(char c)
 {
   return '0' <= c && c <= '9';
 }
 
 /*
 ** Given a pointer into a timezone string, scan until a character that is not
 ** a valid character in a time zone abbreviation is found.
 ** Return a pointer to that character.
 */
 
-static ATTRIBUTE_REPRODUCIBLE const char *
+ATTRIBUTE_REPRODUCIBLE static const char *
 getzname(register const char *strp)
 {
 	register char	c;
 
 	while ((c = *strp) != '\0' && !is_digit(c) && c != ',' && c != '-' &&
 		c != '+')
 			++strp;
 	return strp;
 }
 
 /*
 ** Given a pointer into an extended timezone string, scan until the ending
 ** delimiter of the time zone abbreviation is located.
 ** Return a pointer to the delimiter.
 **
 ** As with getzname above, the legal character set is actually quite
 ** restricted, with other characters producing undefined results.
 ** We don't do any checking here; checking is done later in common-case code.
 */
 
-static ATTRIBUTE_REPRODUCIBLE const char *
+ATTRIBUTE_REPRODUCIBLE static const char *
 getqzname(register const char *strp, const int delim)
 {
 	register int	c;
 
 	while ((c = *strp) != '\0' && c != delim)
 		++strp;
 	return strp;
 }
 
 /*
 ** Given a pointer into a timezone string, extract a number from that string.
 ** Check that the number is within a specified range; if it is not, return
 ** NULL.
 ** Otherwise, return a pointer to the first character not part of the number.
 */
 
 static const char *
 getnum(register const char *strp, int *const nump, const int min, const int max)
 {
 	register char	c;
 	register int	num;
 
 	if (strp == NULL || !is_digit(c = *strp))
 		return NULL;
 	num = 0;
 	do {
 		num = num * 10 + (c - '0');
 		if (num > max)
 			return NULL;	/* illegal value */
 		c = *++strp;
 	} while (is_digit(c));
 	if (num < min)
 		return NULL;		/* illegal value */
 	*nump = num;
 	return strp;
 }
 
 /*
 ** Given a pointer into a timezone string, extract a number of seconds,
 ** in hh[:mm[:ss]] form, from the string.
 ** If any error occurs, return NULL.
 ** Otherwise, return a pointer to the first character not part of the number
 ** of seconds.
 */
 
 static const char *
 getsecs(register const char *strp, int_fast32_t *const secsp)
 {
 	int	num;
 	int_fast32_t secsperhour = SECSPERHOUR;
 
 	/*
 	** 'HOURSPERDAY * DAYSPERWEEK - 1' allows quasi-Posix rules like
 	** "M10.4.6/26", which does not conform to Posix,
 	** but which specifies the equivalent of
 	** "02:00 on the first Sunday on or after 23 Oct".
 	*/
 	strp = getnum(strp, &num, 0, HOURSPERDAY * DAYSPERWEEK - 1);
 	if (strp == NULL)
 		return NULL;
 	*secsp = num * secsperhour;
 	if (*strp == ':') {
 		++strp;
 		strp = getnum(strp, &num, 0, MINSPERHOUR - 1);
 		if (strp == NULL)
 			return NULL;
 		*secsp += num * SECSPERMIN;
 		if (*strp == ':') {
 			++strp;
 			/* 'SECSPERMIN' allows for leap seconds.  */
 			strp = getnum(strp, &num, 0, SECSPERMIN);
 			if (strp == NULL)
 				return NULL;
 			*secsp += num;
 		}
 	}
 	return strp;
 }
 
 /*
 ** Given a pointer into a timezone string, extract an offset, in
 ** [+-]hh[:mm[:ss]] form, from the string.
 ** If any error occurs, return NULL.
 ** Otherwise, return a pointer to the first character not part of the time.
 */
 
 static const char *
 getoffset(register const char *strp, int_fast32_t *const offsetp)
 {
 	register bool neg = false;
 
 	if (*strp == '-') {
 		neg = true;
 		++strp;
 	} else if (*strp == '+')
 		++strp;
 	strp = getsecs(strp, offsetp);
 	if (strp == NULL)
 		return NULL;		/* illegal time */
 	if (neg)
 		*offsetp = -*offsetp;
 	return strp;
 }
 
 /*
 ** Given a pointer into a timezone string, extract a rule in the form
 ** date[/time]. See POSIX section 8 for the format of "date" and "time".
 ** If a valid rule is not found, return NULL.
 ** Otherwise, return a pointer to the first character not part of the rule.
 */
 
 static const char *
 getrule(const char *strp, register struct rule *const rulep)
 {
 	if (*strp == 'J') {
 		/*
 		** Julian day.
 		*/
 		rulep->r_type = JULIAN_DAY;
 		++strp;
 		strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR);
 	} else if (*strp == 'M') {
 		/*
 		** Month, week, day.
 		*/
 		rulep->r_type = MONTH_NTH_DAY_OF_WEEK;
 		++strp;
 		strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR);
 		if (strp == NULL)
 			return NULL;
 		if (*strp++ != '.')
 			return NULL;
 		strp = getnum(strp, &rulep->r_week, 1, 5);
 		if (strp == NULL)
 			return NULL;
 		if (*strp++ != '.')
 			return NULL;
 		strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1);
 	} else if (is_digit(*strp)) {
 		/*
 		** Day of year.
 		*/
 		rulep->r_type = DAY_OF_YEAR;
 		strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1);
 	} else	return NULL;		/* invalid format */
 	if (strp == NULL)
 		return NULL;
 	if (*strp == '/') {
 		/*
 		** Time specified.
 		*/
 		++strp;
 		strp = getoffset(strp, &rulep->r_time);
 	} else	rulep->r_time = 2 * SECSPERHOUR;	/* default = 2:00:00 */
 	return strp;
 }
 
 /*
 ** Given a year, a rule, and the offset from UT at the time that rule takes
 ** effect, calculate the year-relative time that rule takes effect.
 */
 
 static int_fast32_t
 transtime(const int year, register const struct rule *const rulep,
 	  const int_fast32_t offset)
 {
 	register bool	leapyear;
 	register int_fast32_t value;
 	register int	i;
 	int		d, m1, yy0, yy1, yy2, dow;
 
 	leapyear = isleap(year);
 	switch (rulep->r_type) {
 
 	case JULIAN_DAY:
 		/*
 		** Jn - Julian day, 1 == January 1, 60 == March 1 even in leap
 		** years.
 		** In non-leap years, or if the day number is 59 or less, just
 		** add SECSPERDAY times the day number-1 to the time of
 		** January 1, midnight, to get the day.
 		*/
 		value = (rulep->r_day - 1) * SECSPERDAY;
 		if (leapyear && rulep->r_day >= 60)
 			value += SECSPERDAY;
 		break;
 
 	case DAY_OF_YEAR:
 		/*
 		** n - day of year.
 		** Just add SECSPERDAY times the day number to the time of
 		** January 1, midnight, to get the day.
 		*/
 		value = rulep->r_day * SECSPERDAY;
 		break;
 
 	case MONTH_NTH_DAY_OF_WEEK:
 		/*
 		** Mm.n.d - nth "dth day" of month m.
 		*/
 
 		/*
 		** Use Zeller's Congruence to get day-of-week of first day of
 		** month.
 		*/
 		m1 = (rulep->r_mon + 9) % 12 + 1;
 		yy0 = (rulep->r_mon <= 2) ? (year - 1) : year;
 		yy1 = yy0 / 100;
 		yy2 = yy0 % 100;
 		dow = ((26 * m1 - 2) / 10 +
 			1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7;
 		if (dow < 0)
 			dow += DAYSPERWEEK;
 
 		/*
 		** "dow" is the day-of-week of the first day of the month. Get
 		** the day-of-month (zero-origin) of the first "dow" day of the
 		** month.
 		*/
 		d = rulep->r_day - dow;
 		if (d < 0)
 			d += DAYSPERWEEK;
 		for (i = 1; i < rulep->r_week; ++i) {
 			if (d + DAYSPERWEEK >=
 				mon_lengths[leapyear][rulep->r_mon - 1])
 					break;
 			d += DAYSPERWEEK;
 		}
 
 		/*
 		** "d" is the day-of-month (zero-origin) of the day we want.
 		*/
 		value = d * SECSPERDAY;
 		for (i = 0; i < rulep->r_mon - 1; ++i)
 			value += mon_lengths[leapyear][i] * SECSPERDAY;
 		break;
 
 	default: unreachable();
 	}
 
 	/*
 	** "value" is the year-relative time of 00:00:00 UT on the day in
 	** question. To get the year-relative time of the specified local
 	** time on that day, add the transition time and the current offset
 	** from UT.
 	*/
 	return value + rulep->r_time + offset;
 }
 
 /*
 ** Given a POSIX section 8-style TZ string, fill in the rule tables as
 ** appropriate.
 */
 
 static bool
 tzparse(const char *name, struct state *sp, struct state *basep)
 {
 	const char *			stdname;
 	const char *			dstname;
 	int_fast32_t			stdoffset;
 	int_fast32_t			dstoffset;
 	register char *			cp;
 	register bool			load_ok;
 	ptrdiff_t stdlen, dstlen, charcnt;
 	time_t atlo = TIME_T_MIN, leaplo = TIME_T_MIN;
 
 	stdname = name;
 	if (*name == '<') {
 	  name++;
 	  stdname = name;
 	  name = getqzname(name, '>');
 	  if (*name != '>')
 	    return false;
 	  stdlen = name - stdname;
 	  name++;
 	} else {
 	  name = getzname(name);
 	  stdlen = name - stdname;
 	}
-	if (!stdlen)
+	if (! (0 < stdlen && stdlen <= TZNAME_MAXIMUM))
 	  return false;
 	name = getoffset(name, &stdoffset);
 	if (name == NULL)
 	  return false;
 	charcnt = stdlen + 1;
-	if (sizeof sp->chars < charcnt)
-	  return false;
 	if (basep) {
 	  if (0 < basep->timecnt)
 	    atlo = basep->ats[basep->timecnt - 1];
 	  load_ok = false;
 	  sp->leapcnt = basep->leapcnt;
 	  memcpy(sp->lsis, basep->lsis, sp->leapcnt * sizeof *sp->lsis);
 	} else {
 	  load_ok = tzload(TZDEFRULES, sp, false) == 0;
 	  if (!load_ok)
 	    sp->leapcnt = 0;	/* So, we're off a little.  */
 	}
 	if (0 < sp->leapcnt)
 	  leaplo = sp->lsis[sp->leapcnt - 1].ls_trans;
 	if (*name != '\0') {
 		if (*name == '<') {
 			dstname = ++name;
 			name = getqzname(name, '>');
 			if (*name != '>')
 			  return false;
 			dstlen = name - dstname;
 			name++;
 		} else {
 			dstname = name;
 			name = getzname(name);
 			dstlen = name - dstname; /* length of DST abbr. */
 		}
-		if (!dstlen)
+		if (! (0 < dstlen && dstlen <= TZNAME_MAXIMUM))
 		  return false;
 		charcnt += dstlen + 1;
-		if (sizeof sp->chars < charcnt)
-		  return false;
 		if (*name != '\0' && *name != ',' && *name != ';') {
 			name = getoffset(name, &dstoffset);
 			if (name == NULL)
 			  return false;
 		} else	dstoffset = stdoffset - SECSPERHOUR;
 		if (*name == '\0' && !load_ok)
 			name = TZDEFRULESTRING;
 		if (*name == ',' || *name == ';') {
 			struct rule	start;
 			struct rule	end;
 			register int	year;
 			register int	timecnt;
 			time_t		janfirst;
 			int_fast32_t janoffset = 0;
 			int yearbeg, yearlim;
 
 			++name;
 			if ((name = getrule(name, &start)) == NULL)
 			  return false;
 			if (*name++ != ',')
 			  return false;
 			if ((name = getrule(name, &end)) == NULL)
 			  return false;
 			if (*name != '\0')
 			  return false;
 			sp->typecnt = 2;	/* standard time and DST */
 			/*
 			** Two transitions per year, from EPOCH_YEAR forward.
 			*/
 			init_ttinfo(&sp->ttis[0], -stdoffset, false, 0);
 			init_ttinfo(&sp->ttis[1], -dstoffset, true, stdlen + 1);
 			sp->defaulttype = 0;
 			timecnt = 0;
 			janfirst = 0;
 			yearbeg = EPOCH_YEAR;
 
 			do {
 			  int_fast32_t yearsecs
 			    = year_lengths[isleap(yearbeg - 1)] * SECSPERDAY;
 			  yearbeg--;
 			  if (increment_overflow_time(&janfirst, -yearsecs)) {
 			    janoffset = -yearsecs;
 			    break;
 			  }
 			} while (atlo < janfirst
 				 && EPOCH_YEAR - YEARSPERREPEAT / 2 < yearbeg);
 
 			while (true) {
 			  int_fast32_t yearsecs
 			    = year_lengths[isleap(yearbeg)] * SECSPERDAY;
 			  int yearbeg1 = yearbeg;
 			  time_t janfirst1 = janfirst;
 			  if (increment_overflow_time(&janfirst1, yearsecs)
 			      || increment_overflow(&yearbeg1, 1)
 			      || atlo <= janfirst1)
 			    break;
 			  yearbeg = yearbeg1;
 			  janfirst = janfirst1;
 			}
 
 			yearlim = yearbeg;
 			if (increment_overflow(&yearlim, YEARSPERREPEAT + 1))
 			  yearlim = INT_MAX;
 			for (year = yearbeg; year < yearlim; year++) {
 				int_fast32_t
 				  starttime = transtime(year, &start, stdoffset),
 				  endtime = transtime(year, &end, dstoffset);
 				int_fast32_t
 				  yearsecs = (year_lengths[isleap(year)]
 					      * SECSPERDAY);
 				bool reversed = endtime < starttime;
 				if (reversed) {
 					int_fast32_t swap = starttime;
 					starttime = endtime;
 					endtime = swap;
 				}
 				if (reversed
 				    || (starttime < endtime
 					&& endtime - starttime < yearsecs)) {
 					if (TZ_MAX_TIMES - 2 < timecnt)
 						break;
 					sp->ats[timecnt] = janfirst;
 					if (! increment_overflow_time
 					    (&sp->ats[timecnt],
 					     janoffset + starttime)
 					    && atlo <= sp->ats[timecnt])
 					  sp->types[timecnt++] = !reversed;
 					sp->ats[timecnt] = janfirst;
 					if (! increment_overflow_time
 					    (&sp->ats[timecnt],
 					     janoffset + endtime)
 					    && atlo <= sp->ats[timecnt]) {
 					  sp->types[timecnt++] = reversed;
 					}
 				}
 				if (endtime < leaplo) {
 				  yearlim = year;
 				  if (increment_overflow(&yearlim,
 							 YEARSPERREPEAT + 1))
 				    yearlim = INT_MAX;
 				}
 				if (increment_overflow_time
 				    (&janfirst, janoffset + yearsecs))
 					break;
 				janoffset = 0;
 			}
 			sp->timecnt = timecnt;
 			if (! timecnt) {
 				sp->ttis[0] = sp->ttis[1];
 				sp->typecnt = 1;	/* Perpetual DST.  */
 			} else if (YEARSPERREPEAT < year - yearbeg)
 				sp->goback = sp->goahead = true;
 		} else {
 			register int_fast32_t	theirstdoffset;
 			register int_fast32_t	theirdstoffset;
 			register int_fast32_t	theiroffset;
 			register bool		isdst;
 			register int		i;
 			register int		j;
 
 			if (*name != '\0')
 			  return false;
 			/*
 			** Initial values of theirstdoffset and theirdstoffset.
 			*/
 			theirstdoffset = 0;
 			for (i = 0; i < sp->timecnt; ++i) {
 				j = sp->types[i];
 				if (!sp->ttis[j].tt_isdst) {
 					theirstdoffset =
 						- sp->ttis[j].tt_utoff;
 					break;
 				}
 			}
 			theirdstoffset = 0;
 			for (i = 0; i < sp->timecnt; ++i) {
 				j = sp->types[i];
 				if (sp->ttis[j].tt_isdst) {
 					theirdstoffset =
 						- sp->ttis[j].tt_utoff;
 					break;
 				}
 			}
 			/*
 			** Initially we're assumed to be in standard time.
 			*/
 			isdst = false;
 			/*
 			** Now juggle transition times and types
 			** tracking offsets as you do.
 			*/
 			for (i = 0; i < sp->timecnt; ++i) {
 				j = sp->types[i];
 				sp->types[i] = sp->ttis[j].tt_isdst;
 				if (sp->ttis[j].tt_ttisut) {
 					/* No adjustment to transition time */
 				} else {
 					/*
 					** If daylight saving time is in
 					** effect, and the transition time was
 					** not specified as standard time, add
 					** the daylight saving time offset to
 					** the transition time; otherwise, add
 					** the standard time offset to the
 					** transition time.
 					*/
 					/*
 					** Transitions from DST to DDST
 					** will effectively disappear since
 					** POSIX provides for only one DST
 					** offset.
 					*/
 					if (isdst && !sp->ttis[j].tt_ttisstd) {
 						sp->ats[i] += dstoffset -
 							theirdstoffset;
 					} else {
 						sp->ats[i] += stdoffset -
 							theirstdoffset;
 					}
 				}
 				theiroffset = -sp->ttis[j].tt_utoff;
 				if (sp->ttis[j].tt_isdst)
 					theirdstoffset = theiroffset;
 				else	theirstdoffset = theiroffset;
 			}
 			/*
 			** Finally, fill in ttis.
 			*/
 			init_ttinfo(&sp->ttis[0], -stdoffset, false, 0);
 			init_ttinfo(&sp->ttis[1], -dstoffset, true, stdlen + 1);
 			sp->typecnt = 2;
 			sp->defaulttype = 0;
 		}
 	} else {
 		dstlen = 0;
 		sp->typecnt = 1;		/* only standard time */
 		sp->timecnt = 0;
 		init_ttinfo(&sp->ttis[0], -stdoffset, false, 0);
 		sp->defaulttype = 0;
 	}
 	sp->charcnt = charcnt;
 	cp = sp->chars;
 	memcpy(cp, stdname, stdlen);
 	cp += stdlen;
 	*cp++ = '\0';
 	if (dstlen != 0) {
 		memcpy(cp, dstname, dstlen);
 		*(cp + dstlen) = '\0';
 	}
 	return true;
 }
 
 static void
 gmtload(struct state *const sp)
 {
 	if (tzload(etc_utc, sp, true) != 0)
 	  tzparse("UTC0", sp, NULL);
 }
 
 #ifdef DETECT_TZ_CHANGES
 static int
 recheck_tzdata()
 {
 	static time_t last_checked;
 	struct timespec now;
 	time_t current_time;
 	int error;
 
 	/*
 	 * We want to recheck the timezone file every 61 sec.
 	 */
 	error = clock_gettime(CLOCK_MONOTONIC, &now);
 	if (error < 0) {
 		/* XXX: Can we somehow report this? */
 		return 0;
 	}
 
 	current_time = now.tv_sec;
 	if ((current_time - last_checked > DETECT_TZ_CHANGES_INTERVAL) ||
 	    (last_checked > current_time)) {
 		last_checked = current_time;
 		return 1;
 	}
 
 	return 0;
 }
 #else /* !DETECT_TZ_CHANGES */
 #define	recheck_tzdata()	0
 #endif /* !DETECT_TZ_CHANGES */
 
 /* Initialize *SP to a value appropriate for the TZ setting NAME.
    Return 0 on success, an errno value on failure.  */
 static int
 zoneinit(struct state *sp, char const *name)
 {
   if (name && ! name[0]) {
     /*
     ** User wants it fast rather than right.
     */
     sp->leapcnt = 0;		/* so, we're off a little */
     sp->timecnt = 0;
     sp->typecnt = 0;
     sp->charcnt = 0;
     sp->goback = sp->goahead = false;
     init_ttinfo(&sp->ttis[0], 0, false, 0);
     strcpy(sp->chars, utc);
     sp->defaulttype = 0;
     return 0;
   } else {
     int err = tzload(name, sp, true);
     if (err != 0 && name && name[0] != ':' && tzparse(name, sp, NULL))
       err = 0;
     if (err == 0)
-      scrub_abbrs(sp);
+      err = scrub_abbrs(sp);
     return err;
   }
 }
 
 static void
 tzset_unlocked_name(char const *name)
 {
   struct state *sp = lclptr;
   int lcl = name ? strlen(name) < sizeof lcl_TZname : -1;
   if (lcl < 0
       ? lcl_is_set < 0
       : 0 < lcl_is_set && strcmp(lcl_TZname, name) == 0)
     if (recheck_tzdata() == 0)
       return;
 #ifdef ALL_STATE
   if (! sp)
     lclptr = sp = malloc(sizeof *lclptr);
 #endif /* defined ALL_STATE */
   if (sp) {
     if (zoneinit(sp, name) != 0)
       zoneinit(sp, "");
     if (0 < lcl)
       strcpy(lcl_TZname, name);
   }
   settzname();
   lcl_is_set = lcl;
 }
 
 static void
 tzset_unlocked(void)
 {
   tzset_unlocked_name(getenv("TZ"));
 }
 
 void
 tzset(void)
 {
   if (lock() != 0)
     return;
   tzset_unlocked();
   unlock();
 }
 
 void
 freebsd13_tzsetwall(void)
 {
   if (lock() != 0)
     return;
   tzset_unlocked_name(NULL);
   unlock();
 }
 __sym_compat(tzsetwall, freebsd13_tzsetwall, FBSD_1.0);
 __warn_references(tzsetwall,
     "warning: tzsetwall() is deprecated, use tzset() instead.");
 
 static void
 gmtcheck(void)
 {
   static bool gmt_is_set;
   if (lock() != 0)
     return;
   if (! gmt_is_set) {
 #ifdef ALL_STATE
     gmtptr = malloc(sizeof *gmtptr);
 #endif
     if (gmtptr)
       gmtload(gmtptr);
     gmt_is_set = true;
   }
   unlock();
 }
 
 #if NETBSD_INSPIRED
 
 timezone_t
 tzalloc(char const *name)
 {
   timezone_t sp = malloc(sizeof *sp);
   if (sp) {
     int err = zoneinit(sp, name);
     if (err != 0) {
       free(sp);
       errno = err;
       return NULL;
     }
   } else if (!HAVE_MALLOC_ERRNO)
     errno = ENOMEM;
   return sp;
 }
 
 void
 tzfree(timezone_t sp)
 {
   free(sp);
 }
 
 /*
 ** NetBSD 6.1.4 has ctime_rz, but omit it because POSIX says ctime and
 ** ctime_r are obsolescent and have potential security problems that
 ** ctime_rz would share.  Callers can instead use localtime_rz + strftime.
 **
 ** NetBSD 6.1.4 has tzgetname, but omit it because it doesn't work
 ** in zones with three or more time zone abbreviations.
 ** Callers can instead use localtime_rz + strftime.
 */
 
 #endif
 
 /*
 ** The easy way to behave "as if no library function calls" localtime
 ** is to not call it, so we drop its guts into "localsub", which can be
 ** freely called. (And no, the PANS doesn't require the above behavior,
 ** but it *is* desirable.)
 **
 ** If successful and SETNAME is nonzero,
 ** set the applicable parts of tzname, timezone and altzone;
 ** however, it's OK to omit this step if the timezone is POSIX-compatible,
 ** since in that case tzset should have already done this step correctly.
 ** SETNAME's type is int_fast32_t for compatibility with gmtsub,
 ** but it is actually a boolean and its value should be 0 or 1.
 */
 
 /*ARGSUSED*/
 static struct tm *
 localsub(struct state const *sp, time_t const *timep, int_fast32_t setname,
 	 struct tm *const tmp)
 {
 	register const struct ttinfo *	ttisp;
 	register int			i;
 	register struct tm *		result;
 	const time_t			t = *timep;
 
 	if (sp == NULL) {
 	  /* Don't bother to set tzname etc.; tzset has already done it.  */
 	  return gmtsub(gmtptr, timep, 0, tmp);
 	}
 	if ((sp->goback && t < sp->ats[0]) ||
 		(sp->goahead && t > sp->ats[sp->timecnt - 1])) {
 			time_t newt;
 			register time_t		seconds;
 			register time_t		years;
 
 			if (t < sp->ats[0])
 				seconds = sp->ats[0] - t;
 			else	seconds = t - sp->ats[sp->timecnt - 1];
 			--seconds;
 
 			/* Beware integer overflow, as SECONDS might
 			   be close to the maximum time_t.  */
 			years = seconds / SECSPERREPEAT * YEARSPERREPEAT;
 			seconds = years * AVGSECSPERYEAR;
 			years += YEARSPERREPEAT;
 			if (t < sp->ats[0])
 			  newt = t + seconds + SECSPERREPEAT;
 			else
 			  newt = t - seconds - SECSPERREPEAT;
 
 			if (newt < sp->ats[0] ||
 				newt > sp->ats[sp->timecnt - 1])
 					return NULL;	/* "cannot happen" */
 			result = localsub(sp, &newt, setname, tmp);
 			if (result) {
 #if defined ckd_add && defined ckd_sub
 				if (t < sp->ats[0]
 				    ? ckd_sub(&result->tm_year,
 					      result->tm_year, years)
 				    : ckd_add(&result->tm_year,
 					      result->tm_year, years))
 				  return NULL;
 #else
 				register int_fast64_t newy;
 
 				newy = result->tm_year;
 				if (t < sp->ats[0])
 					newy -= years;
 				else	newy += years;
 				if (! (INT_MIN <= newy && newy <= INT_MAX))
 					return NULL;
 				result->tm_year = newy;
 #endif
 			}
 			return result;
 	}
 	if (sp->timecnt == 0 || t < sp->ats[0]) {
 		i = sp->defaulttype;
 	} else {
 		register int	lo = 1;
 		register int	hi = sp->timecnt;
 
 		while (lo < hi) {
 			register int	mid = (lo + hi) >> 1;
 
 			if (t < sp->ats[mid])
 				hi = mid;
 			else	lo = mid + 1;
 		}
 		i = sp->types[lo - 1];
 	}
 	ttisp = &sp->ttis[i];
 	/*
 	** To get (wrong) behavior that's compatible with System V Release 2.0
 	** you'd replace the statement below with
 	**	t += ttisp->tt_utoff;
 	**	timesub(&t, 0L, sp, tmp);
 	*/
 	result = timesub(&t, ttisp->tt_utoff, sp, tmp);
 	if (result) {
 	  result->tm_isdst = ttisp->tt_isdst;
 #ifdef TM_ZONE
 	  result->TM_ZONE = (char *) &sp->chars[ttisp->tt_desigidx];
 #endif /* defined TM_ZONE */
 	  if (setname)
 	    update_tzname_etc(sp, ttisp);
 	}
 	return result;
 }
 
 #if NETBSD_INSPIRED
 
 struct tm *
-localtime_rz(struct state *sp, time_t const *timep, struct tm *tmp)
+localtime_rz(struct state *restrict sp, time_t const *restrict timep,
+	     struct tm *restrict tmp)
 {
   return localsub(sp, timep, 0, tmp);
 }
 
 #endif
 
 static struct tm *
 localtime_tzset(time_t const *timep, struct tm *tmp, bool setname)
 {
   int err = lock();
   if (err) {
     errno = err;
     return NULL;
   }
 #ifndef DETECT_TZ_CHANGES
   if (setname || !lcl_is_set)
 #endif
     tzset_unlocked();
   tmp = localsub(lclptr, timep, setname, tmp);
   unlock();
   return tmp;
 }
 
 static void
 localtime_key_init(void)
 {
 
 	localtime_key_error = _pthread_key_create(&localtime_key, free);
 }
 
 struct tm *
 localtime(const time_t *timep)
 {
+#if !SUPPORT_C89
+	static struct tm tm;
+#endif
 	struct tm *p_tm = &tm;
 
 	if (__isthreaded != 0) {
 		_pthread_once(&localtime_once, localtime_key_init);
 		if (localtime_key_error != 0) {
 			errno = localtime_key_error;
 			return (NULL);
 		}
 		if ((p_tm = _pthread_getspecific(localtime_key)) == NULL) {
 			if ((p_tm = malloc(sizeof(*p_tm))) == NULL) {
 				return (NULL);
 			}
 			if (_pthread_setspecific(localtime_key, p_tm) != 0) {
 				free(p_tm);
 				return (NULL);
 			}
 		}
 	}
 	return localtime_tzset(timep, p_tm, true);
 }
 
 struct tm *
-localtime_r(const time_t *timep, struct tm *tmp)
+localtime_r(const time_t *restrict timep, struct tm *restrict tmp)
 {
   return localtime_tzset(timep, tmp, false);
 }
 
 /*
 ** gmtsub is to gmtime as localsub is to localtime.
 */
 
 static struct tm *
 gmtsub(ATTRIBUTE_MAYBE_UNUSED struct state const *sp, time_t const *timep,
        int_fast32_t offset, struct tm *tmp)
 {
 	register struct tm *	result;
 
 	result = timesub(timep, offset, gmtptr, tmp);
 #ifdef TM_ZONE
 	/*
 	** Could get fancy here and deliver something such as
 	** "+xx" or "-xx" if offset is non-zero,
 	** but this is no time for a treasure hunt.
 	*/
 	tmp->TM_ZONE = ((char *)
 			(offset ? wildabbr : gmtptr ? gmtptr->chars : utc));
 #endif /* defined TM_ZONE */
 	return result;
 }
 
 /*
 * Re-entrant version of gmtime.
 */
 
 struct tm *
-gmtime_r(const time_t *timep, struct tm *tmp)
+gmtime_r(time_t const *restrict timep, struct tm *restrict tmp)
 {
 	_once(&gmt_once, gmtcheck);
 	return gmtsub(gmtptr, timep, 0, tmp);
 }
 
 static void
 gmtime_key_init(void)
 {
 
 	gmtime_key_error = _pthread_key_create(&gmtime_key, free);
 }
 
 struct tm *
 gmtime(const time_t *timep)
 {
+#if !SUPPORT_C89
+	static struct tm tm;
+#endif
 	struct tm *p_tm = &tm;
 
 	if (__isthreaded != 0) {
 		_pthread_once(&gmtime_once, gmtime_key_init);
 		if (gmtime_key_error != 0) {
 			errno = gmtime_key_error;
 			return (NULL);
 		}
 		if ((p_tm = _pthread_getspecific(gmtime_key)) == NULL) {
 			if ((p_tm = malloc(sizeof(*p_tm))) == NULL) {
 				return (NULL);
 			}
 			if (_pthread_setspecific(gmtime_key, p_tm) != 0) {
 				free(p_tm);
 				return (NULL);
 			}
 		}
 	}
 	return gmtime_r(timep, p_tm);
 }
 
-#ifdef STD_INSPIRED
+#if STD_INSPIRED
+
+struct tm *
+offtime_r(time_t const *restrict timep, long offset, struct tm *restrict tmp)
+{
+	_once(&gmt_once, gmtcheck);
+	return gmtsub(gmtptr, timep, offset, tmp);
+}
+
+static void
+offtime_key_init(void)
+{
+
+	offtime_key_error = _pthread_key_create(&offtime_key, free);
+}
 
 struct tm *
 offtime(const time_t *timep, long offset)
 {
-  _once(&gmt_once, gmtcheck);
-  return gmtsub(gmtptr, timep, offset, &tm);
+#if !SUPPORT_C89
+	static struct tm tm;
+#endif
+	struct tm *p_tm = &tm;
+
+	if (__isthreaded != 0) {
+		_pthread_once(&offtime_once, offtime_key_init);
+		if (offtime_key_error != 0) {
+			errno = offtime_key_error;
+			return (NULL);
+		}
+		if ((p_tm = _pthread_getspecific(offtime_key)) == NULL) {
+			if ((p_tm = malloc(sizeof(*p_tm))) == NULL) {
+				return (NULL);
+			}
+			if (_pthread_setspecific(offtime_key, p_tm) != 0) {
+				free(p_tm);
+				return (NULL);
+			}
+		}
+	}
+	return offtime_r(timep, offset, p_tm);
 }
 
-#endif /* defined STD_INSPIRED */
+#endif
 
 /*
 ** Return the number of leap years through the end of the given year
 ** where, to make the math easy, the answer for year zero is defined as zero.
 */
 
 static time_t
 leaps_thru_end_of_nonneg(time_t y)
 {
   return y / 4 - y / 100 + y / 400;
 }
 
 static time_t
 leaps_thru_end_of(time_t y)
 {
   return (y < 0
 	  ? -1 - leaps_thru_end_of_nonneg(-1 - y)
 	  : leaps_thru_end_of_nonneg(y));
 }
 
 static struct tm *
 timesub(const time_t *timep, int_fast32_t offset,
 	const struct state *sp, struct tm *tmp)
 {
 	register const struct lsinfo *	lp;
 	register time_t			tdays;
 	register const int *		ip;
 	register int_fast32_t		corr;
 	register int			i;
 	int_fast32_t idays, rem, dayoff, dayrem;
 	time_t y;
 
 	/* If less than SECSPERMIN, the number of seconds since the
 	   most recent positive leap second; otherwise, do not add 1
 	   to localtime tm_sec because of leap seconds.  */
 	time_t secs_since_posleap = SECSPERMIN;
 
 	corr = 0;
 	i = (sp == NULL) ? 0 : sp->leapcnt;
 	while (--i >= 0) {
 		lp = &sp->lsis[i];
 		if (*timep >= lp->ls_trans) {
 			corr = lp->ls_corr;
 			if ((i == 0 ? 0 : lp[-1].ls_corr) < corr)
 			  secs_since_posleap = *timep - lp->ls_trans;
 			break;
 		}
 	}
 
 	/* Calculate the year, avoiding integer overflow even if
 	   time_t is unsigned.  */
 	tdays = *timep / SECSPERDAY;
 	rem = *timep % SECSPERDAY;
 	rem += offset % SECSPERDAY - corr % SECSPERDAY + 3 * SECSPERDAY;
 	dayoff = offset / SECSPERDAY - corr / SECSPERDAY + rem / SECSPERDAY - 3;
 	rem %= SECSPERDAY;
 	/* y = (EPOCH_YEAR
 	        + floor((tdays + dayoff) / DAYSPERREPEAT) * YEARSPERREPEAT),
 	   sans overflow.  But calculate against 1570 (EPOCH_YEAR -
 	   YEARSPERREPEAT) instead of against 1970 so that things work
 	   for localtime values before 1970 when time_t is unsigned.  */
 	dayrem = tdays % DAYSPERREPEAT;
 	dayrem += dayoff % DAYSPERREPEAT;
 	y = (EPOCH_YEAR - YEARSPERREPEAT
 	     + ((1 + dayoff / DAYSPERREPEAT + dayrem / DAYSPERREPEAT
 		 - ((dayrem % DAYSPERREPEAT) < 0)
 		 + tdays / DAYSPERREPEAT)
 		* YEARSPERREPEAT));
 	/* idays = (tdays + dayoff) mod DAYSPERREPEAT, sans overflow.  */
 	idays = tdays % DAYSPERREPEAT;
 	idays += dayoff % DAYSPERREPEAT + 2 * DAYSPERREPEAT;
 	idays %= DAYSPERREPEAT;
 	/* Increase Y and decrease IDAYS until IDAYS is in range for Y.  */
 	while (year_lengths[isleap(y)] <= idays) {
 		int tdelta = idays / DAYSPERLYEAR;
 		int_fast32_t ydelta = tdelta + !tdelta;
 		time_t newy = y + ydelta;
 		register int	leapdays;
 		leapdays = leaps_thru_end_of(newy - 1) -
 			leaps_thru_end_of(y - 1);
 		idays -= ydelta * DAYSPERNYEAR;
 		idays -= leapdays;
 		y = newy;
 	}
 
 #ifdef ckd_add
 	if (ckd_add(&tmp->tm_year, y, -TM_YEAR_BASE)) {
 	  errno = EOVERFLOW;
 	  return NULL;
 	}
 #else
 	if (!TYPE_SIGNED(time_t) && y < TM_YEAR_BASE) {
 	  int signed_y = y;
 	  tmp->tm_year = signed_y - TM_YEAR_BASE;
 	} else if ((!TYPE_SIGNED(time_t) || INT_MIN + TM_YEAR_BASE <= y)
 		   && y - TM_YEAR_BASE <= INT_MAX)
 	  tmp->tm_year = y - TM_YEAR_BASE;
 	else {
 	  errno = EOVERFLOW;
 	  return NULL;
 	}
 #endif
 	tmp->tm_yday = idays;
 	/*
 	** The "extra" mods below avoid overflow problems.
 	*/
 	tmp->tm_wday = (TM_WDAY_BASE
 			+ ((tmp->tm_year % DAYSPERWEEK)
 			   * (DAYSPERNYEAR % DAYSPERWEEK))
 			+ leaps_thru_end_of(y - 1)
 			- leaps_thru_end_of(TM_YEAR_BASE - 1)
 			+ idays);
 	tmp->tm_wday %= DAYSPERWEEK;
 	if (tmp->tm_wday < 0)
 		tmp->tm_wday += DAYSPERWEEK;
 	tmp->tm_hour = rem / SECSPERHOUR;
 	rem %= SECSPERHOUR;
 	tmp->tm_min = rem / SECSPERMIN;
 	tmp->tm_sec = rem % SECSPERMIN;
 
 	/* Use "... ??:??:60" at the end of the localtime minute containing
 	   the second just before the positive leap second.  */
 	tmp->tm_sec += secs_since_posleap <= tmp->tm_sec;
 
 	ip = mon_lengths[isleap(y)];
 	for (tmp->tm_mon = 0; idays >= ip[tmp->tm_mon]; ++(tmp->tm_mon))
 		idays -= ip[tmp->tm_mon];
 	tmp->tm_mday = idays + 1;
 	tmp->tm_isdst = 0;
 #ifdef TM_GMTOFF
 	tmp->TM_GMTOFF = offset;
 #endif /* defined TM_GMTOFF */
 	return tmp;
 }
 
-char *
-ctime(const time_t *timep)
-{
-/*
-** Section 4.12.3.2 of X3.159-1989 requires that
-**	The ctime function converts the calendar time pointed to by timer
-**	to local time in the form of a string. It is equivalent to
-**		asctime(localtime(timer))
-*/
-  struct tm *tmp = localtime(timep);
-  return tmp ? asctime(tmp) : NULL;
-}
-
-char *
-ctime_r(const time_t *timep, char *buf)
-{
-  struct tm mytm;
-  struct tm *tmp = localtime_r(timep, &mytm);
-  return tmp ? asctime_r(tmp, buf) : NULL;
-}
-
 /*
 ** Adapted from code provided by Robert Elz, who writes:
 **	The "best" way to do mktime I think is based on an idea of Bob
 **	Kridle's (so its said...) from a long time ago.
 **	It does a binary search of the time_t space. Since time_t's are
 **	just 32 bits, its a max of 32 iterations (even at 64 bits it
 **	would still be very reasonable).
 */
 
 #ifndef WRONG
 # define WRONG (-1)
 #endif /* !defined WRONG */
 
 /*
 ** Normalize logic courtesy Paul Eggert.
 */
 
 static bool
 increment_overflow(int *ip, int j)
 {
 #ifdef ckd_add
 	return ckd_add(ip, *ip, j);
 #else
 	register int const	i = *ip;
 
 	/*
 	** If i >= 0 there can only be overflow if i + j > INT_MAX
 	** or if j > INT_MAX - i; given i >= 0, INT_MAX - i cannot overflow.
 	** If i < 0 there can only be overflow if i + j < INT_MIN
 	** or if j < INT_MIN - i; given i < 0, INT_MIN - i cannot overflow.
 	*/
 	if ((i >= 0) ? (j > INT_MAX - i) : (j < INT_MIN - i))
 		return true;
 	*ip += j;
 	return false;
 #endif
 }
 
 static bool
 increment_overflow32(int_fast32_t *const lp, int const m)
 {
 #ifdef ckd_add
 	return ckd_add(lp, *lp, m);
 #else
 	register int_fast32_t const	l = *lp;
 
 	if ((l >= 0) ? (m > INT_FAST32_MAX - l) : (m < INT_FAST32_MIN - l))
 		return true;
 	*lp += m;
 	return false;
 #endif
 }
 
 static bool
 increment_overflow_time(time_t *tp, int_fast32_t j)
 {
 #ifdef ckd_add
 	return ckd_add(tp, *tp, j);
 #else
 	/*
 	** This is like
 	** 'if (! (TIME_T_MIN <= *tp + j && *tp + j <= TIME_T_MAX)) ...',
 	** except that it does the right thing even if *tp + j would overflow.
 	*/
 	if (! (j < 0
 	       ? (TYPE_SIGNED(time_t) ? TIME_T_MIN - j <= *tp : -1 - j < *tp)
 	       : *tp <= TIME_T_MAX - j))
 		return true;
 	*tp += j;
 	return false;
 #endif
 }
 
 static bool
 normalize_overflow(int *const tensptr, int *const unitsptr, const int base)
 {
 	register int	tensdelta;
 
 	tensdelta = (*unitsptr >= 0) ?
 		(*unitsptr / base) :
 		(-1 - (-1 - *unitsptr) / base);
 	*unitsptr -= tensdelta * base;
 	return increment_overflow(tensptr, tensdelta);
 }
 
 static bool
 normalize_overflow32(int_fast32_t *tensptr, int *unitsptr, int base)
 {
 	register int	tensdelta;
 
 	tensdelta = (*unitsptr >= 0) ?
 		(*unitsptr / base) :
 		(-1 - (-1 - *unitsptr) / base);
 	*unitsptr -= tensdelta * base;
 	return increment_overflow32(tensptr, tensdelta);
 }
 
 static int
 tmcomp(register const struct tm *const atmp,
        register const struct tm *const btmp)
 {
 	register int	result;
 
 	if (atmp->tm_year != btmp->tm_year)
 		return atmp->tm_year < btmp->tm_year ? -1 : 1;
 	if ((result = (atmp->tm_mon - btmp->tm_mon)) == 0 &&
 		(result = (atmp->tm_mday - btmp->tm_mday)) == 0 &&
 		(result = (atmp->tm_hour - btmp->tm_hour)) == 0 &&
 		(result = (atmp->tm_min - btmp->tm_min)) == 0)
 			result = atmp->tm_sec - btmp->tm_sec;
 	return result;
 }
 
 /* Copy to *DEST from *SRC.  Copy only the members needed for mktime,
    as other members might not be initialized.  */
 static void
 mktmcpy(struct tm *dest, struct tm const *src)
 {
   dest->tm_sec = src->tm_sec;
   dest->tm_min = src->tm_min;
   dest->tm_hour = src->tm_hour;
   dest->tm_mday = src->tm_mday;
   dest->tm_mon = src->tm_mon;
   dest->tm_year = src->tm_year;
   dest->tm_isdst = src->tm_isdst;
 #if defined TM_GMTOFF && ! UNINIT_TRAP
   dest->TM_GMTOFF = src->TM_GMTOFF;
 #endif
 }
 
 static time_t
 time2sub(struct tm *const tmp,
 	 struct tm *(*funcp)(struct state const *, time_t const *,
 			     int_fast32_t, struct tm *),
 	 struct state const *sp,
 	 const int_fast32_t offset,
 	 bool *okayp,
 	 bool do_norm_secs)
 {
 	register int			dir;
 	register int			i, j;
 	register int			saved_seconds;
 	register int_fast32_t		li;
 	register time_t			lo;
 	register time_t			hi;
 	int_fast32_t			y;
 	time_t				newt;
 	time_t				t;
 	struct tm			yourtm, mytm;
 
 	*okayp = false;
 	mktmcpy(&yourtm, tmp);
 
 	if (do_norm_secs) {
 		if (normalize_overflow(&yourtm.tm_min, &yourtm.tm_sec,
 			SECSPERMIN))
 				return WRONG;
 	}
 	if (normalize_overflow(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR))
 		return WRONG;
 	if (normalize_overflow(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY))
 		return WRONG;
 	y = yourtm.tm_year;
 	if (normalize_overflow32(&y, &yourtm.tm_mon, MONSPERYEAR))
 		return WRONG;
 	/*
 	** Turn y into an actual year number for now.
 	** It is converted back to an offset from TM_YEAR_BASE later.
 	*/
 	if (increment_overflow32(&y, TM_YEAR_BASE))
 		return WRONG;
 	while (yourtm.tm_mday <= 0) {
 		if (increment_overflow32(&y, -1))
 			return WRONG;
 		li = y + (1 < yourtm.tm_mon);
 		yourtm.tm_mday += year_lengths[isleap(li)];
 	}
 	while (yourtm.tm_mday > DAYSPERLYEAR) {
 		li = y + (1 < yourtm.tm_mon);
 		yourtm.tm_mday -= year_lengths[isleap(li)];
 		if (increment_overflow32(&y, 1))
 			return WRONG;
 	}
 	for ( ; ; ) {
 		i = mon_lengths[isleap(y)][yourtm.tm_mon];
 		if (yourtm.tm_mday <= i)
 			break;
 		yourtm.tm_mday -= i;
 		if (++yourtm.tm_mon >= MONSPERYEAR) {
 			yourtm.tm_mon = 0;
 			if (increment_overflow32(&y, 1))
 				return WRONG;
 		}
 	}
 #ifdef ckd_add
 	if (ckd_add(&yourtm.tm_year, y, -TM_YEAR_BASE))
 	  return WRONG;
 #else
 	if (increment_overflow32(&y, -TM_YEAR_BASE))
 		return WRONG;
 	if (! (INT_MIN <= y && y <= INT_MAX))
 		return WRONG;
 	yourtm.tm_year = y;
 #endif
 	if (yourtm.tm_sec >= 0 && yourtm.tm_sec < SECSPERMIN)
 		saved_seconds = 0;
 	else if (yourtm.tm_year < EPOCH_YEAR - TM_YEAR_BASE) {
 		/*
 		** We can't set tm_sec to 0, because that might push the
 		** time below the minimum representable time.
 		** Set tm_sec to 59 instead.
 		** This assumes that the minimum representable time is
 		** not in the same minute that a leap second was deleted from,
 		** which is a safer assumption than using 58 would be.
 		*/
 		if (increment_overflow(&yourtm.tm_sec, 1 - SECSPERMIN))
 			return WRONG;
 		saved_seconds = yourtm.tm_sec;
 		yourtm.tm_sec = SECSPERMIN - 1;
 	} else {
 		saved_seconds = yourtm.tm_sec;
 		yourtm.tm_sec = 0;
 	}
 	/*
 	** Do a binary search (this works whatever time_t's type is).
 	*/
 	lo = TIME_T_MIN;
 	hi = TIME_T_MAX;
 	for ( ; ; ) {
 		t = lo / 2 + hi / 2;
 		if (t < lo)
 			t = lo;
 		else if (t > hi)
 			t = hi;
 		if (! funcp(sp, &t, offset, &mytm)) {
 			/*
 			** Assume that t is too extreme to be represented in
 			** a struct tm; arrange things so that it is less
 			** extreme on the next pass.
 			*/
 			dir = (t > 0) ? 1 : -1;
 		} else	dir = tmcomp(&mytm, &yourtm);
 		if (dir != 0) {
 			if (t == lo) {
 				if (t == TIME_T_MAX)
 					return WRONG;
 				++t;
 				++lo;
 			} else if (t == hi) {
 				if (t == TIME_T_MIN)
 					return WRONG;
 				--t;
 				--hi;
 			}
 			if (lo > hi)
 				return WRONG;
 			if (dir > 0)
 				hi = t;
 			else	lo = t;
 			continue;
 		}
 #if defined TM_GMTOFF && ! UNINIT_TRAP
 		if (mytm.TM_GMTOFF != yourtm.TM_GMTOFF
 		    && (yourtm.TM_GMTOFF < 0
 			? (-SECSPERDAY <= yourtm.TM_GMTOFF
 			   && (mytm.TM_GMTOFF <=
 			       (min(INT_FAST32_MAX, LONG_MAX)
 				+ yourtm.TM_GMTOFF)))
 			: (yourtm.TM_GMTOFF <= SECSPERDAY
 			   && ((max(INT_FAST32_MIN, LONG_MIN)
 				+ yourtm.TM_GMTOFF)
 			       <= mytm.TM_GMTOFF)))) {
 		  /* MYTM matches YOURTM except with the wrong UT offset.
 		     YOURTM.TM_GMTOFF is plausible, so try it instead.
 		     It's OK if YOURTM.TM_GMTOFF contains uninitialized data,
 		     since the guess gets checked.  */
 		  time_t altt = t;
 		  int_fast32_t diff = mytm.TM_GMTOFF - yourtm.TM_GMTOFF;
 		  if (!increment_overflow_time(&altt, diff)) {
 		    struct tm alttm;
 		    if (funcp(sp, &altt, offset, &alttm)
 			&& alttm.tm_isdst == mytm.tm_isdst
 			&& alttm.TM_GMTOFF == yourtm.TM_GMTOFF
 			&& tmcomp(&alttm, &yourtm) == 0) {
 		      t = altt;
 		      mytm = alttm;
 		    }
 		  }
 		}
 #endif
 		if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst)
 			break;
 		/*
 		** Right time, wrong type.
 		** Hunt for right time, right type.
 		** It's okay to guess wrong since the guess
 		** gets checked.
 		*/
 		if (sp == NULL)
 			return WRONG;
 		for (i = sp->typecnt - 1; i >= 0; --i) {
 			if (sp->ttis[i].tt_isdst != yourtm.tm_isdst)
 				continue;
 			for (j = sp->typecnt - 1; j >= 0; --j) {
 				if (sp->ttis[j].tt_isdst == yourtm.tm_isdst)
 					continue;
 				if (ttunspecified(sp, j))
 				  continue;
 				newt = (t + sp->ttis[j].tt_utoff
 					- sp->ttis[i].tt_utoff);
 				if (! funcp(sp, &newt, offset, &mytm))
 					continue;
 				if (tmcomp(&mytm, &yourtm) != 0)
 					continue;
 				if (mytm.tm_isdst != yourtm.tm_isdst)
 					continue;
 				/*
 				** We have a match.
 				*/
 				t = newt;
 				goto label;
 			}
 		}
 		return WRONG;
 	}
 label:
 	newt = t + saved_seconds;
 	if ((newt < t) != (saved_seconds < 0))
 		return WRONG;
 	t = newt;
 	if (funcp(sp, &t, offset, tmp))
 		*okayp = true;
 	return t;
 }
 
 static time_t
 time2(struct tm * const	tmp,
       struct tm *(*funcp)(struct state const *, time_t const *,
 			  int_fast32_t, struct tm *),
       struct state const *sp,
       const int_fast32_t offset,
       bool *okayp)
 {
 	time_t	t;
 
 	/*
 	** First try without normalization of seconds
 	** (in case tm_sec contains a value associated with a leap second).
 	** If that fails, try with normalization of seconds.
 	*/
 	t = time2sub(tmp, funcp, sp, offset, okayp, false);
 	return *okayp ? t : time2sub(tmp, funcp, sp, offset, okayp, true);
 }
 
 static time_t
 time1(struct tm *const tmp,
       struct tm *(*funcp)(struct state const *, time_t const *,
 			  int_fast32_t, struct tm *),
       struct state const *sp,
       const int_fast32_t offset)
 {
 	register time_t			t;
 	register int			samei, otheri;
 	register int			sameind, otherind;
 	register int			i;
 	register int			nseen;
 	char				seen[TZ_MAX_TYPES];
 	unsigned char			types[TZ_MAX_TYPES];
 	bool				okay;
 
 	if (tmp == NULL) {
 		errno = EINVAL;
 		return WRONG;
 	}
 
 	if (tmp->tm_isdst > 1)
 		tmp->tm_isdst = 1;
 	t = time2(tmp, funcp, sp, offset, &okay);
 	if (okay)
 		return t;
 	if (tmp->tm_isdst < 0)
 #ifdef PCTS
 		/*
 		** POSIX Conformance Test Suite code courtesy Grant Sullivan.
 		*/
 		tmp->tm_isdst = 0;	/* reset to std and try again */
 #else
 		return t;
 #endif /* !defined PCTS */
 	/*
 	** We're supposed to assume that somebody took a time of one type
 	** and did some math on it that yielded a "struct tm" that's bad.
 	** We try to divine the type they started from and adjust to the
 	** type they need.
 	*/
 	if (sp == NULL)
 		return WRONG;
 	for (i = 0; i < sp->typecnt; ++i)
 		seen[i] = false;
 	nseen = 0;
 	for (i = sp->timecnt - 1; i >= 0; --i)
 		if (!seen[sp->types[i]] && !ttunspecified(sp, sp->types[i])) {
 			seen[sp->types[i]] = true;
 			types[nseen++] = sp->types[i];
 		}
 	for (sameind = 0; sameind < nseen; ++sameind) {
 		samei = types[sameind];
 		if (sp->ttis[samei].tt_isdst != tmp->tm_isdst)
 			continue;
 		for (otherind = 0; otherind < nseen; ++otherind) {
 			otheri = types[otherind];
 			if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst)
 				continue;
 			tmp->tm_sec += (sp->ttis[otheri].tt_utoff
 					- sp->ttis[samei].tt_utoff);
 			tmp->tm_isdst = !tmp->tm_isdst;
 			t = time2(tmp, funcp, sp, offset, &okay);
 			if (okay)
 				return t;
 			tmp->tm_sec -= (sp->ttis[otheri].tt_utoff
 					- sp->ttis[samei].tt_utoff);
 			tmp->tm_isdst = !tmp->tm_isdst;
 		}
 	}
 	return WRONG;
 }
 
 static time_t
 mktime_tzname(struct state *sp, struct tm *tmp, bool setname)
 {
   if (sp)
     return time1(tmp, localsub, sp, setname);
   else {
     _once(&gmt_once, gmtcheck);
     return time1(tmp, gmtsub, gmtptr, 0);
   }
 }
 
 #if NETBSD_INSPIRED
 
 time_t
-mktime_z(struct state *sp, struct tm *tmp)
+mktime_z(struct state *restrict sp, struct tm *restrict tmp)
 {
   return mktime_tzname(sp, tmp, false);
 }
 
 #endif
 
 time_t
 mktime(struct tm *tmp)
 {
   time_t t;
   int err = lock();
   if (err) {
     errno = err;
     return -1;
   }
   tzset_unlocked();
   t = mktime_tzname(lclptr, tmp, true);
   unlock();
   return t;
 }
 
-#ifdef STD_INSPIRED
+#if STD_INSPIRED
 time_t
 timelocal(struct tm *tmp)
 {
 	if (tmp != NULL)
 		tmp->tm_isdst = -1;	/* in case it wasn't initialized */
 	return mktime(tmp);
 }
 #else
 static
 #endif
 time_t
 timeoff(struct tm *tmp, long offset)
 {
   if (tmp)
     tmp->tm_isdst = 0;
   _once(&gmt_once, gmtcheck);
   return time1(tmp, gmtsub, gmtptr, offset);
 }
 
 time_t
 timegm(struct tm *tmp)
 {
   time_t t;
   struct tm tmcpy;
   mktmcpy(&tmcpy, tmp);
   tmcpy.tm_wday = -1;
   t = timeoff(&tmcpy, 0);
   if (0 <= tmcpy.tm_wday)
     *tmp = tmcpy;
   return t;
 }
 
 static int_fast32_t
 leapcorr(struct state const *sp, time_t t)
 {
 	register struct lsinfo const *	lp;
 	register int			i;
 
 	i = sp->leapcnt;
 	while (--i >= 0) {
 		lp = &sp->lsis[i];
 		if (t >= lp->ls_trans)
 			return lp->ls_corr;
 	}
 	return 0;
 }
 
 /*
 ** XXX--is the below the right way to conditionalize??
 */
 
-#ifdef STD_INSPIRED
+#if STD_INSPIRED
 
 /* NETBSD_INSPIRED_EXTERN functions are exported to callers if
    NETBSD_INSPIRED is defined, and are private otherwise.  */
 # if NETBSD_INSPIRED
 #  define NETBSD_INSPIRED_EXTERN
 # else
 #  define NETBSD_INSPIRED_EXTERN static
 # endif
 
 /*
 ** IEEE Std 1003.1 (POSIX) says that 536457599
 ** shall correspond to "Wed Dec 31 23:59:59 UTC 1986", which
 ** is not the case if we are accounting for leap seconds.
 ** So, we provide the following conversion routines for use
 ** when exchanging timestamps with POSIX conforming systems.
 */
 
 NETBSD_INSPIRED_EXTERN time_t
 time2posix_z(struct state *sp, time_t t)
 {
   return t - leapcorr(sp, t);
 }
 
 time_t
 time2posix(time_t t)
 {
   int err = lock();
   if (err) {
     errno = err;
     return -1;
   }
 #ifndef DETECT_TZ_CHANGES
   if (!lcl_is_set)
 #endif
     tzset_unlocked();
   if (lclptr)
     t = time2posix_z(lclptr, t);
   unlock();
   return t;
 }
 
 NETBSD_INSPIRED_EXTERN time_t
 posix2time_z(struct state *sp, time_t t)
 {
 	time_t	x;
 	time_t	y;
 	/*
 	** For a positive leap second hit, the result
 	** is not unique. For a negative leap second
 	** hit, the corresponding time doesn't exist,
 	** so we return an adjacent second.
 	*/
 	x = t + leapcorr(sp, t);
 	y = x - leapcorr(sp, x);
 	if (y < t) {
 		do {
 			x++;
 			y = x - leapcorr(sp, x);
 		} while (y < t);
 		x -= y != t;
 	} else if (y > t) {
 		do {
 			--x;
 			y = x - leapcorr(sp, x);
 		} while (y > t);
 		x += y != t;
 	}
 	return x;
 }
 
 time_t
 posix2time(time_t t)
 {
   int err = lock();
   if (err) {
     errno = err;
     return -1;
   }
 #ifndef DETECT_TZ_CHANGES
   if (!lcl_is_set)
 #endif
     tzset_unlocked();
   if (lclptr)
     t = posix2time_z(lclptr, t);
   unlock();
   return t;
 }
 
-#endif /* defined STD_INSPIRED */
+#endif /* STD_INSPIRED */
 
 #if TZ_TIME_T
 
 # if !USG_COMPAT
 #  define daylight 0
 #  define timezone 0
 # endif
 # if !ALTZONE
 #  define altzone 0
 # endif
 
 /* Convert from the underlying system's time_t to the ersatz time_tz,
    which is called 'time_t' in this file.  Typically, this merely
    converts the time's integer width.  On some platforms, the system
    time is local time not UT, or uses some epoch other than the POSIX
    epoch.
 
    Although this code appears to define a function named 'time' that
    returns time_t, the macros in private.h cause this code to actually
    define a function named 'tz_time' that returns tz_time_t.  The call
    to sys_time invokes the underlying system's 'time' function.  */
 
 time_t
 time(time_t *p)
 {
   time_t r = sys_time(0);
   if (r != (time_t) -1) {
     int_fast32_t offset = EPOCH_LOCAL ? (daylight ? timezone : altzone) : 0;
     if (increment_overflow32(&offset, -EPOCH_OFFSET)
 	|| increment_overflow_time(&r, offset)) {
       errno = EOVERFLOW;
       r = -1;
     }
   }
   if (p)
     *p = r;
   return r;
 }
 
 #endif
diff --git a/contrib/tzcode/newctime.3 b/contrib/tzcode/newctime.3
index e25d841ef537..05bb7deaba51 100644
--- a/contrib/tzcode/newctime.3
+++ b/contrib/tzcode/newctime.3
@@ -1,344 +1,358 @@
 .\" This file is in the public domain, so clarified as of
 .\" 2009-05-17 by Arthur David Olson.
-.TH NEWCTIME 3
+.TH newctime 3 "" "Time Zone Database"
 .SH NAME
 asctime, ctime, difftime, gmtime, localtime, mktime \- convert date and time
 .SH SYNOPSIS
 .nf
 .ie \n(.g .ds - \f(CR-\fP
 .el .ds - \-
 .B #include 
 .PP
 .BR "extern char *tzname[];" " /\(** (optional) \(**/"
 .PP
-.B char *ctime(time_t const *clock);
+.B [[deprecated]] char *ctime(time_t const *clock);
 .PP
 .B char *ctime_r(time_t const *clock, char *buf);
 .PP
 .B double difftime(time_t time1, time_t time0);
 .PP
-.B char *asctime(struct tm const *tm);
+.B [[deprecated]] char *asctime(struct tm const *tm);
 .PP
 .B "char *asctime_r(struct tm const *restrict tm,"
 .B "    char *restrict result);"
 .PP
 .B struct tm *localtime(time_t const *clock);
 .PP
 .B "struct tm *localtime_r(time_t const *restrict clock,"
 .B "    struct tm *restrict result);"
 .PP
 .B "struct tm *localtime_rz(timezone_t restrict zone,"
 .B "    time_t const *restrict clock,"
 .B "    struct tm *restrict result);"
 .PP
 .B struct tm *gmtime(time_t const *clock);
 .PP
 .B "struct tm *gmtime_r(time_t const *restrict clock,"
 .B "    struct tm *restrict result);"
 .PP
 .B time_t mktime(struct tm *tm);
 .PP
 .B "time_t mktime_z(timezone_t restrict zone,"
 .B "    struct tm *restrict tm);"
 .PP
 .B cc ... \*-ltz
 .fi
 .SH DESCRIPTION
 .ie '\(en'' .ds en \-
 .el .ds en \(en
 .ie '\(lq'' .ds lq \&"\"
 .el .ds lq \(lq\"
 .ie '\(rq'' .ds rq \&"\"
 .el .ds rq \(rq\"
 .de q
 \\$3\*(lq\\$1\*(rq\\$2
 ..
 The
 .B ctime
 function
 converts a long integer, pointed to by
 .IR clock ,
 and returns a pointer to a
 string of the form
 .br
 .ce
 .eo
 Thu Nov 24 18:22:48 1986\n\0
 .br
 .ec
 Years requiring fewer than four characters are padded with leading zeroes.
 For years longer than four characters, the string is of the form
 .br
 .ce
 .eo
 Thu Nov 24 18:22:48     81986\n\0
 .ec
 .br
 with five spaces before the year.
 These unusual formats are designed to make it less likely that older
 software that expects exactly 26 bytes of output will mistakenly output
 misleading values for out-of-range years.
 .PP
 The
 .BI * clock
 timestamp represents the time in seconds since 1970-01-01 00:00:00
 Coordinated Universal Time (UTC).
 The POSIX standard says that timestamps must be nonnegative
 and must ignore leap seconds.
 Many implementations extend POSIX by allowing negative timestamps,
 and can therefore represent timestamps that predate the
 introduction of UTC and are some other flavor of Universal Time (UT).
 Some implementations support leap seconds, in contradiction to POSIX.
 .PP
 The
+.B ctime
+function is deprecated starting in C23.
+Callers can use
+.B localtime_r
+and
+.B strftime
+instead.
+.PP
+The
 .B localtime
 and
 .B gmtime
 functions
 return pointers to
 .q "tm"
 structures, described below.
 The
 .B localtime
 function
 corrects for the time zone and any time zone adjustments
 (such as Daylight Saving Time in the United States).
 After filling in the
 .q "tm"
 structure,
 .B localtime
 sets the
 .BR tm_isdst 'th
 element of
 .B tzname
 to a pointer to a string that's the time zone abbreviation to be used with
 .BR localtime 's
 return value.
 .PP
 The
 .B gmtime
 function
 converts to Coordinated Universal Time.
 .PP
 The
 .B asctime
 function
 converts a time value contained in a
 .q "tm"
 structure to a string,
 as shown in the above example,
 and returns a pointer to the string.
+This function is deprecated starting in C23.
+Callers can use
+.B strftime
+instead.
 .PP
 The
 .B mktime
 function
 converts the broken-down time,
 expressed as local time,
 in the structure pointed to by
 .I tm
 into a calendar time value with the same encoding as that of the values
 returned by the
 .B time
 function.
 The original values of the
 .B tm_wday
 and
 .B tm_yday
 components of the structure are ignored,
 and the original values of the other components are not restricted
 to their normal ranges.
 (A positive or zero value for
 .B tm_isdst
 causes
 .B mktime
 to presume initially that daylight saving time
 respectively,
 is or is not in effect for the specified time.
 A negative value for
 .B tm_isdst
 causes the
 .B mktime
 function to attempt to divine whether daylight saving time is in effect
 for the specified time; in this case it does not use a consistent
 rule and may give a different answer when later
 presented with the same argument.)
 On successful completion, the values of the
 .B tm_wday
 and
 .B tm_yday
 components of the structure are set appropriately,
 and the other components are set to represent the specified calendar time,
 but with their values forced to their normal ranges; the final value of
 .B tm_mday
 is not set until
 .B tm_mon
 and
 .B tm_year
 are determined.
 The
 .B mktime
 function
 returns the specified calendar time;
 If the calendar time cannot be represented,
 it returns \-1.
 .PP
 The
 .B difftime
 function
 returns the difference between two calendar times,
 .RI ( time1
 \-
 .IR time0 ),
 expressed in seconds.
 .PP
 The
 .BR ctime_r ,
 .BR localtime_r ,
 .BR gmtime_r ,
 and
 .B asctime_r
 functions
 are like their unsuffixed counterparts, except that they accept an
 additional argument specifying where to store the result if successful.
 .PP
 The
 .B localtime_rz
 and
 .B mktime_z
 functions
 are like their unsuffixed counterparts, except that they accept an
 extra initial
 .B zone
 argument specifying the timezone to be used for conversion.
 If
 .B zone
 is null, UT is used; otherwise,
 .B zone
 should be have been allocated by
 .B tzalloc
 and should not be freed until after all uses (e.g., by calls to
 .BR strftime )
 of the filled-in
 .B tm_zone
 fields.
 .PP
 Declarations of all the functions and externals, and the
 .q "tm"
 structure,
 are in the
 .B 
 header file.
 The structure (of type)
 .B struct tm
 includes the following fields:
 .RS
 .PP
 .nf
 .ta 2n +\w'long tm_gmtoff;nn'u
 	int tm_sec;	/\(** seconds (0\*(en60) \(**/
 	int tm_min;	/\(** minutes (0\*(en59) \(**/
 	int tm_hour;	/\(** hours (0\*(en23) \(**/
 	int tm_mday;	/\(** day of month (1\*(en31) \(**/
 	int tm_mon;	/\(** month of year (0\*(en11) \(**/
 	int tm_year;	/\(** year \- 1900 \(**/
 	int tm_wday;	/\(** day of week (Sunday = 0) \(**/
 	int tm_yday;	/\(** day of year (0\*(en365) \(**/
 	int tm_isdst;	/\(** is daylight saving time in effect? \(**/
 	char \(**tm_zone;	/\(** time zone abbreviation (optional) \(**/
 	long tm_gmtoff;	/\(** offset from UT in seconds (optional) \(**/
 .fi
 .RE
 .PP
 The
 .B tm_isdst
 field
 is non-zero if daylight saving time is in effect.
 .PP
 The
 .B tm_gmtoff
 field
 is the offset (in seconds) of the time represented
 from UT, with positive values indicating east
 of the Prime Meridian.
 The field's name is derived from Greenwich Mean Time, a precursor of UT.
 .PP
 In
 .B "struct tm"
 the
 .B tm_zone
 and
 .B tm_gmtoff
 fields exist, and are filled in, only if arrangements to do
 so were made when the library containing these functions was
 created.
 Similarly, the
 .B tzname
 variable is optional; also, there is no guarantee that
 .B tzname
 will
 continue to exist in this form in future releases of this code.
 .SH FILES
 .ta \w'/usr/share/zoneinfo/posixrules\0\0'u
 /usr/share/zoneinfo	timezone information directory
 .br
 /usr/share/zoneinfo/localtime	local timezone file
 .br
-/usr/share/zoneinfo/posixrules	used with POSIX-style TZ's
+/usr/share/zoneinfo/posixrules	default DST rules (obsolete,
+	and can cause bugs if present)
 .br
 /usr/share/zoneinfo/GMT	for UTC leap seconds
 .sp
 If
 .B /usr/share/zoneinfo/GMT
 is absent,
 UTC leap seconds are loaded from
 .BR /usr/share/zoneinfo/posixrules .
 .SH SEE ALSO
 getenv(3),
 newstrftime(3),
 newtzset(3),
 time(2),
 tzfile(5)
 .SH NOTES
 The return values of
 .BR asctime ,
 .BR ctime ,
 .BR gmtime ,
 and
 .B localtime
 point to static data
 overwritten by each call.
 The
 .B tzname
 variable (once set) and the
 .B tm_zone
 field of a returned
 .B "struct tm"
 both point to an array of characters that
 can be freed or overwritten by later calls to the functions
 .BR localtime ,
 .BR tzfree ,
 and
 .BR tzset ,
 if these functions affect the timezone information that specifies the
 abbreviation in question.
 The remaining functions and data are thread-safe.
 .PP
 The
 .BR asctime ,
 .BR asctime_r ,
 .BR ctime ,
 and
 .B ctime_r
 functions
 behave strangely for years before 1000 or after 9999.
 The 1989 and 1999 editions of the C Standard say
 that years from \-99 through 999 are converted without
 extra spaces, but this conflicts with longstanding
 tradition and with this implementation.
 The 2011 edition says that the behavior
 is undefined if the year is before 1000 or after 9999.
 Traditional implementations of these two functions are
 restricted to years in the range 1900 through 2099.
 To avoid this portability mess, new programs should use
 .B strftime
 instead.
diff --git a/contrib/tzcode/newstrftime.3 b/contrib/tzcode/newstrftime.3
index d5d8ee104d9f..432c3e889344 100644
--- a/contrib/tzcode/newstrftime.3
+++ b/contrib/tzcode/newstrftime.3
@@ -1,290 +1,290 @@
 .\" strftime man page
 .\"
 .\" Based on the UCB file whose corrected copyright information appears below.
 .\" Copyright 1989, 1991 The Regents of the University of California.
 .\" All rights reserved.
 .\"
 .\" This code is derived from software contributed to Berkeley by
 .\" the American National Standards Committee X3, on Information
 .\" Processing Systems.
 .\"
 .\" Redistribution and use in source and binary forms, with or without
 .\" modification, are permitted provided that the following conditions
 .\" are met:
 .\" 1. Redistributions of source code must retain the above copyright
 .\"    notice, this list of conditions and the following disclaimer.
 .\" 2. Redistributions in binary form must reproduce the above copyright
 .\"    notice, this list of conditions and the following disclaimer in the
 .\"    documentation and/or other materials provided with the distribution.
 .\" 3. Neither the name of the University nor the names of its contributors
 .\"    may be used to endorse or promote products derived from this software
 .\"    without specific prior written permission.
 .\"
 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS" AND
 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 .\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
 .\"     from: @(#)strftime.3	5.12 (Berkeley) 6/29/91
 .\"	$Id: strftime.3,v 1.4 1993/12/15 20:33:00 jtc Exp $
 .\"
-.TH NEWSTRFTIME 3
+.TH newstrftime 3 "" "Time Zone Database"
 .SH NAME
 strftime \- format date and time
 .SH SYNOPSIS
 .nf
 .ie \n(.g .ds - \f(CR-\fP
 .el .ds - \-
 .B #include 
 .PP
 .B "size_t strftime(char *restrict buf, size_t maxsize,"
 .B "    char const *restrict format, struct tm const *restrict timeptr);"
 .PP
 .B cc ... \-ltz
 .fi
 .SH DESCRIPTION
 .ie '\(lq'' .ds lq \&"\"
 .el .ds lq \(lq\"
 .ie '\(rq'' .ds rq \&"\"
 .el .ds rq \(rq\"
 .de c
 .ie \n(.g \f(CR\\$1\fP\\$2
 .el \\$1\\$2
 ..
 .de q
 \\$3\*(lq\\$1\*(rq\\$2
 ..
 The
 .B strftime
 function formats the information from
 .I timeptr
 into the array pointed to by
 .I buf
 according to the string pointed to by
 .IR format .
 .PP
 The
 .I format
 string consists of zero or more conversion specifications and
 ordinary characters.
 All ordinary characters are copied directly into the array.
 A conversion specification consists of a percent sign
 .Ql %
 and one other character.
 .PP
 No more than
 .I maxsize
 bytes are placed into the array.
 .PP
 Each conversion specification is replaced by the characters as
 follows which are then copied into the array.
 .TP
 %A
 is replaced by the locale's full weekday name.
 .TP
 %a
 is replaced by the locale's abbreviated weekday name.
 .TP
 %B
 is replaced by the locale's full month name.
 .TP
 %b or %h
 is replaced by the locale's abbreviated month name.
 .TP
 %C
 is replaced by the century (a year divided by 100 and truncated to an integer)
 as a decimal number [00,99].
 .TP
 %c
 is replaced by the locale's appropriate date and time representation.
 .TP
 %D
 is equivalent to
 .c %m/%d/%y .
 .TP
 %d
 is replaced by the day of the month as a decimal number [01,31].
 .TP
 %e
 is replaced by the day of month as a decimal number [1,31];
 single digits are preceded by a blank.
 .TP
 %F
 is equivalent to
 .c %Y-%m-%d
 (the ISO 8601 date format).
 .TP
 %G
 is replaced by the ISO 8601 year with century as a decimal number.
 See also the
 .c %V
 conversion specification.
 .TP
 %g
 is replaced by the ISO 8601 year without century as a decimal number [00,99].
 This is the year that includes the greater part of the week.
 (Monday as the first day of a week).
 See also the
 .c %V
 conversion specification.
 .TP
 %H
 is replaced by the hour (24-hour clock) as a decimal number [00,23].
 .TP
 %I
 is replaced by the hour (12-hour clock) as a decimal number [01,12].
 .TP
 %j
 is replaced by the day of the year as a decimal number [001,366].
 .TP
 %k
 is replaced by the hour (24-hour clock) as a decimal number [0,23];
 single digits are preceded by a blank.
 .TP
 %l
 is replaced by the hour (12-hour clock) as a decimal number [1,12];
 single digits are preceded by a blank.
 .TP
 %M
 is replaced by the minute as a decimal number [00,59].
 .TP
 %m
 is replaced by the month as a decimal number [01,12].
 .TP
 %n
 is replaced by a newline.
 .TP
 %p
 is replaced by the locale's equivalent of either
 .q AM
 or
 .q PM .
 .TP
 %R
 is replaced by the time in the format
 .c %H:%M .
 .TP
 %r
 is replaced by the locale's representation of 12-hour clock time
 using AM/PM notation.
 .TP
 %S
 is replaced by the second as a decimal number [00,60].
 The range of
 seconds is [00,60] instead of [00,59] to allow for the periodic occurrence
 of leap seconds.
 .TP
 %s
 is replaced by the number of seconds since the Epoch (see
 .BR ctime (3)).
 .TP
 %T
 is replaced by the time in the format
 .c %H:%M:%S .
 .TP
 %t
 is replaced by a tab.
 .TP
 %U
 is replaced by the week number of the year (Sunday as the first day of
 the week) as a decimal number [00,53].
 .TP
 %u
 is replaced by the weekday (Monday as the first day of the week)
 as a decimal number [1,7].
 .TP
 %V
 is replaced by the week number of the year (Monday as the first day of
 the week) as a decimal number [01,53].  If the week containing January
 1 has four or more days in the new year, then it is week 1; otherwise
 it is week 53 of the previous year, and the next week is week 1.
 The year is given by the
 .c %G
 conversion specification.
 .TP
 %W
 is replaced by the week number of the year (Monday as the first day of
 the week) as a decimal number [00,53].
 .TP
 %w
 is replaced by the weekday (Sunday as the first day of the week)
 as a decimal number [0,6].
 .TP
 %X
 is replaced by the locale's appropriate time representation.
 .TP
 %x
 is replaced by the locale's appropriate date representation.
 .TP
 %Y
 is replaced by the year with century as a decimal number.
 .TP
 %y
 is replaced by the year without century as a decimal number [00,99].
 .TP
 %Z
 is replaced by the time zone abbreviation,
 or by the empty string if this is not determinable.
 .TP
 %z
 is replaced by the offset from the Prime Meridian
 in the format +HHMM or \*-HHMM (ISO 8601) as appropriate,
 with positive values representing locations east of Greenwich,
 or by the empty string if this is not determinable.
 The numeric time zone abbreviation \*-0000 is used when the time is
 Universal Time
 but local time is indeterminate; by convention this is used for
 locations while uninhabited, and corresponds to a zero offset when the
 time zone abbreviation begins with
 .q "\*-" .
 .TP
 %%
 is replaced by a single %.
 .TP
 %+
 is replaced by the locale's date and time in
 .BR date (1)
 format.
 .SH "RETURN VALUE"
 If the conversion is successful,
 .B strftime
 returns the number of bytes placed into the array, not counting the
 terminating NUL;
 .B errno
 is unchanged if the returned value is zero.
 Otherwise,
 .B errno
 is set to indicate the error, zero is returned,
 and the array contents are unspecified.
 .SH ERRORS
 This function fails if:
 .TP
 [ERANGE]
 The total number of resulting bytes, including the terminating
 NUL character, is more than
 .IR maxsize .
 .PP
 This function may fail if:
 .TP
 [EOVERFLOW]
 The format includes an
 .c %s
 conversion and the number of seconds since the Epoch cannot be represented
 in a
 .c time_t .
 .SH SEE ALSO
 date(1),
 getenv(3),
 newctime(3),
 newtzset(3),
 time(2),
 tzfile(5)
 .SH BUGS
 There is no conversion specification for the phase of the moon.
diff --git a/contrib/tzcode/newtzset.3 b/contrib/tzcode/newtzset.3
index 1e75acf0e6e3..78b6b6ce67c4 100644
--- a/contrib/tzcode/newtzset.3
+++ b/contrib/tzcode/newtzset.3
@@ -1,350 +1,351 @@
 .\" This file is in the public domain, so clarified as of
 .\" 2009-05-17 by Arthur David Olson.
-.TH NEWTZSET 3
+.TH newtzset 3 "" "Time Zone Database"
 .SH NAME
 tzset \- initialize time conversion information
 .SH SYNOPSIS
 .nf
 .ie \n(.g .ds - \f(CR-\fP
 .el .ds - \-
 .B #include 
 .PP
 .B timezone_t tzalloc(char const *TZ);
 .PP
 .B void tzfree(timezone_t tz);
 .PP
 .B void tzset(void);
 .PP
 .B cc ... \*-ltz
 .fi
 .SH DESCRIPTION
 .ie '\(en'' .ds en \-
 .el .ds en \(en
 .ie '\(lq'' .ds lq \&"\"
 .el .ds lq \(lq\"
 .ie '\(rq'' .ds rq \&"\"
 .el .ds rq \(rq\"
 .de q
 \\$3\*(lq\\$1\*(rq\\$2
 ..
 The
 .B tzalloc
 function
 allocates and returns a timezone object described by
 .BR TZ .
 If
 .B TZ
 is not a valid timezone description, or if the object cannot be allocated,
 .B tzalloc
 returns a null pointer and sets
 .BR errno .
 .PP
 The
 .B tzfree
 function
 frees a timezone object
 .BR tz ,
 which should have been successfully allocated by
 .BR tzalloc .
 This invalidates any
 .B tm_zone
 pointers that
 .B tz
 was used to set.
 .PP
 The
 .B tzset
 function
 acts like
 .BR tzalloc(getenv("TZ")) ,
 except it saves any resulting timezone object into internal
 storage that is accessed by
 .BR localtime ,
 .BR localtime_r ,
 and
 .BR mktime .
 The anonymous shared timezone object is freed by the next call to
 .BR tzset .
 If the implied call to
 .B tzalloc
 fails,
 .B tzset
 falls back on Universal Time (UT).
 .PP
 If
 .B TZ
 is null, the best available approximation to local (wall
 clock) time, as specified by the
 .BR tzfile (5)-format
 file
 .B localtime
 in the system time conversion information directory, is used.
 If
 .B TZ
 is the empty string,
 UT is used, with the abbreviation "UTC"
 and without leap second correction; please see
 .BR newctime (3)
 for more about UT, UTC, and leap seconds.  If
 .B TZ
 is nonnull and nonempty:
 .IP
 if the value begins with a colon, it is used as a pathname of a file
 from which to read the time conversion information;
 .IP
 if the value does not begin with a colon, it is first used as the
 pathname of a file from which to read the time conversion information,
 and, if that file cannot be read, is used directly as a specification of
 the time conversion information.
 .PP
 When
 .B TZ
 is used as a pathname, if it begins with a slash,
 it is used as an absolute pathname; otherwise,
 it is used as a pathname relative to a system time conversion information
 directory.
 The file must be in the format specified in
 .BR tzfile (5).
 .PP
 When
 .B TZ
 is used directly as a specification of the time conversion information,
 it must have the following syntax (spaces inserted for clarity):
 .IP
 \fIstd\|offset\fR[\fIdst\fR[\fIoffset\fR][\fB,\fIrule\fR]]
 .PP
 Where:
 .RS
 .TP 15
 .IR std " and " dst
 Three or more bytes that are the designation for the standard
 .RI ( std )
 or the alternative
 .RI ( dst ,
 such as daylight saving time)
 time zone.  Only
 .I std
 is required; if
 .I dst
 is missing, then daylight saving time does not apply in this locale.
 Upper- and lowercase letters are explicitly allowed.  Any characters
 except a leading colon
 .RB ( : ),
 digits, comma
 .RB ( , ),
 ASCII minus
 .RB ( \*- ),
 ASCII plus
 .RB ( + ),
 and NUL bytes are allowed.
 Alternatively, a designation can be surrounded by angle brackets
 .B <
 and
 .BR > ;
 in this case, the designation can contain any characters other than
 .B >
 and NUL.
 .TP
 .I offset
 Indicates the value one must add to the local time to arrive at
 Coordinated Universal Time.  The
 .I offset
 has the form:
 .RS
 .IP
 \fIhh\fR[\fB:\fImm\fR[\fB:\fIss\fR]]
 .RE
 .IP
 The minutes
 .RI ( mm )
 and seconds
 .RI ( ss )
 are optional.  The hour
 .RI ( hh )
 is required and may be a single digit.  The
 .I offset
 following
 .I std
 is required.  If no
 .I offset
 follows
 .IR dst ,
 daylight saving time is assumed to be one hour ahead of standard time.  One or
 more digits may be used; the value is always interpreted as a decimal
 number.  The hour must be between zero and 24, and the minutes (and
 seconds) \*(en if present \*(en between zero and 59.  If preceded by a
 .q "\*-" ,
 the time zone shall be east of the Prime Meridian; otherwise it shall be
 west (which may be indicated by an optional preceding
 .q "+" .
 .TP
 .I rule
 Indicates when to change to and back from daylight saving time.  The
 .I rule
 has the form:
 .RS
 .IP
 \fIdate\fB/\fItime\fB,\fIdate\fB/\fItime\fR
 .RE
 .IP
 where the first
 .I date
 describes when the change from standard to daylight saving time occurs and the
 second
 .I date
 describes when the change back happens.  Each
 .I time
 field describes when, in current local time, the change to the other
 time is made.
 As an extension to POSIX, daylight saving is assumed to be in effect
 all year if it begins January 1 at 00:00 and ends December 31 at
 24:00 plus the difference between daylight saving and standard time,
 leaving no room for standard time in the calendar.
 .IP
 The format of
 .I date
 is one of the following:
 .RS
 .TP 10
 .BI J n
 The Julian day
 .I n
 .RI "(1\ \(<=" "\ n\ " "\(<=\ 365).
 Leap days are not counted; that is, in all years \*(en including leap
 years \*(en February 28 is day 59 and March 1 is day 60.  It is
 impossible to explicitly refer to the occasional February 29.
 .TP
 .I n
 The zero-based Julian day
 .RI "(0\ \(<=" "\ n\ " "\(<=\ 365).
 Leap days are counted, and it is possible to refer to February 29.
 .TP
 .BI M m . n . d
 The
 .IR d' th
 day
 .RI "(0\ \(<=" "\ d\ " "\(<=\ 6)
 of week
 .I n
 of month
 .I m
 of the year
 .RI "(1\ \(<=" "\ n\ " "\(<=\ 5,
 .RI "1\ \(<=" "\ m\ " "\(<=\ 12,
 where week 5 means
 .q "the last \fId\fP day in month \fIm\fP"
 which may occur in either the fourth or the fifth week).  Week 1 is the
 first week in which the
 .IR d' th
 day occurs.  Day zero is Sunday.
 .RE
 .IP "" 15
 The
 .I time
 has the same format as
 .I offset
 except that POSIX does not allow a leading sign (\c
 .q "\*-"
 or
 .q "+" ).
 As an extension to POSIX, the hours part of
 .I time
 can range from \-167 through 167; this allows for unusual rules such
 as
 .q "the Saturday before the first Sunday of March" .
 The default, if
 .I time
 is not given, is
 .BR 02:00:00 .
 .RE
 .LP
 Here are some examples of
 .B TZ
 values that directly specify the timezone; they use some of the
 extensions to POSIX.
 .TP
 .B EST5
 stands for US Eastern Standard
 Time (EST), 5 hours behind UT, without daylight saving.
 .TP
 .B <+12>\*-12<+13>,M11.1.0,M1.2.1/147
 stands for Fiji time, 12 hours ahead
 of UT, springing forward on November's first Sunday at 02:00, and
 falling back on January's second Monday at 147:00 (i.e., 03:00 on the
 first Sunday on or after January 14).  The abbreviations for standard
 and daylight saving time are
 .q "+12"
 and
 .q "+13".
 .TP
 .B IST\*-2IDT,M3.4.4/26,M10.5.0
 stands for Israel Standard Time (IST) and Israel Daylight Time (IDT),
 2 hours ahead of UT, springing forward on March's fourth
 Thursday at 26:00 (i.e., 02:00 on the first Friday on or after March
 23), and falling back on October's last Sunday at 02:00.
 .TP
 .B <\*-04>4<\*-03>,J1/0,J365/25
 stands for permanent daylight saving time, 3 hours behind UT with
 abbreviation
 .q "\*-03".
 There is a dummy fall-back transition on December 31 at 25:00 daylight
 saving time (i.e., 24:00 standard time, equivalent to January 1 at
 00:00 standard time), and a simultaneous spring-forward transition on
 January 1 at 00:00 standard time, so daylight saving time is in effect
 all year and the initial
 .B <\*-04>
 is a placeholder.
 .TP
 .B <\*-03>3<\*-02>,M3.5.0/\*-2,M10.5.0/\*-1
 stands for time in western Greenland, 3 hours behind UT, where clocks
 follow the EU rules of
 springing forward on March's last Sunday at 01:00 UT (\-02:00 local
 time, i.e., 22:00 the previous day) and falling back on October's last
 Sunday at 01:00 UT (\-01:00 local time, i.e., 23:00 the previous day).
 The abbreviations for standard and daylight saving time are
 .q "\*-03"
 and
 .q "\*-02".
 .PP
 If no
 .I rule
 is present in
 .BR TZ ,
 the rules specified
 by the
 .BR tzfile (5)-format
 file
 .B posixrules
 in the system time conversion information directory are used, with the
 standard and daylight saving time offsets from UT replaced by those specified by
 the
 .I offset
 values in
 .BR TZ .
 .PP
 For compatibility with System V Release 3.1, a semicolon
 .RB ( ; )
 may be used to separate the
 .I rule
 from the rest of the specification.
 .SH FILES
 .ta \w'/usr/share/zoneinfo/posixrules\0\0'u
 /usr/share/zoneinfo	timezone information directory
 .br
 /usr/share/zoneinfo/localtime	local timezone file
 .br
-/usr/share/zoneinfo/posixrules	used with POSIX-style TZ
+/usr/share/zoneinfo/posixrules	default DST rules (obsolete,
+	and can cause bugs if present)
 .br
 /usr/share/zoneinfo/GMT	for UTC leap seconds
 .sp
 If
 .B /usr/share/zoneinfo/GMT
 is absent,
 UTC leap seconds are loaded from
 .BR /usr/share/zoneinfo/posixrules .
 .SH SEE ALSO
 getenv(3),
 newctime(3),
 newstrftime(3),
 time(2),
 tzfile(5)
diff --git a/contrib/tzcode/private.h b/contrib/tzcode/private.h
index 35d2444d4ec1..44a927622987 100644
--- a/contrib/tzcode/private.h
+++ b/contrib/tzcode/private.h
@@ -1,938 +1,1011 @@
 /* Private header for tzdb code.  */
 
 #ifndef PRIVATE_H
 
 #define PRIVATE_H
 
 /*
 ** This file is in the public domain, so clarified as of
 ** 1996-06-05 by Arthur David Olson.
 */
 
 /*
 ** This header is for use ONLY with the time conversion code.
 ** There is no guarantee that it will remain unchanged,
 ** or that it will remain at all.
 ** Do NOT copy it to any system include directory.
 ** Thank you!
 */
 
+/* PORT_TO_C89 means the code should work even if the underlying
+   compiler and library support only C89.  SUPPORT_C89 means the
+   tzcode library should support C89 callers in addition to the usual
+   support for C99-and-later callers.  These macros are obsolescent,
+   and the plan is to remove them along with any code needed only when
+   they are nonzero.  */
+#ifndef PORT_TO_C89
+# define PORT_TO_C89 0
+#endif
+#ifndef SUPPORT_C89
+# define SUPPORT_C89 0
+#endif
+
 #ifndef __STDC_VERSION__
 # define __STDC_VERSION__ 0
 #endif
 
 /* Define true, false and bool if they don't work out of the box.  */
-#if __STDC_VERSION__ < 199901
+#if PORT_TO_C89 && __STDC_VERSION__ < 199901
 # define true 1
 # define false 0
 # define bool int
 #elif __STDC_VERSION__ < 202311
 # include 
 #endif
 
+#if __STDC_VERSION__ < 202311
+# define static_assert(cond) extern int static_assert_check[(cond) ? 1 : -1]
+#endif
+
 /*
 ** zdump has been made independent of the rest of the time
 ** conversion package to increase confidence in the verification it provides.
 ** You can use zdump to help in verifying other implementations.
 ** To do this, compile with -DUSE_LTZ=0 and link without the tz library.
 */
 #ifndef USE_LTZ
 # define USE_LTZ 1
 #endif
 
 /* This string was in the Factory zone through version 2016f.  */
 #define GRANDPARENTED	"Local time zone must be set--use tzsetup"
 
 /*
 ** Defaults for preprocessor symbols.
 ** You can override these in your C compiler options, e.g. '-DHAVE_GETTEXT=1'.
 */
 
 #ifndef HAVE_DECL_ASCTIME_R
 # define HAVE_DECL_ASCTIME_R 1
 #endif
 
-#if !defined HAVE_GENERIC && defined __has_extension
+#if !defined HAVE__GENERIC && defined __has_extension
 # if __has_extension(c_generic_selections)
-#  define HAVE_GENERIC 1
+#  define HAVE__GENERIC 1
 # else
-#  define HAVE_GENERIC 0
+#  define HAVE__GENERIC 0
 # endif
 #endif
 /* _Generic is buggy in pre-4.9 GCC.  */
-#if !defined HAVE_GENERIC && defined __GNUC__ && !defined __STRICT_ANSI__
-# define HAVE_GENERIC (4 < __GNUC__ + (9 <= __GNUC_MINOR__))
+#if !defined HAVE__GENERIC && defined __GNUC__ && !defined __STRICT_ANSI__
+# define HAVE__GENERIC (4 < __GNUC__ + (9 <= __GNUC_MINOR__))
 #endif
-#ifndef HAVE_GENERIC
-# define HAVE_GENERIC (201112 <= __STDC_VERSION__)
+#ifndef HAVE__GENERIC
+# define HAVE__GENERIC (201112 <= __STDC_VERSION__)
 #endif
 
 #if !defined HAVE_GETTEXT && defined __has_include
 # if __has_include()
 #  define HAVE_GETTEXT true
 # endif
 #endif
 #ifndef HAVE_GETTEXT
 # define HAVE_GETTEXT false
 #endif
 
 #ifndef HAVE_INCOMPATIBLE_CTIME_R
 # define HAVE_INCOMPATIBLE_CTIME_R 0
 #endif
 
 #ifndef HAVE_LINK
 # define HAVE_LINK 1
 #endif /* !defined HAVE_LINK */
 
 #ifndef HAVE_MALLOC_ERRNO
 # define HAVE_MALLOC_ERRNO 1
 #endif
 
 #ifndef HAVE_POSIX_DECLS
 # define HAVE_POSIX_DECLS 1
 #endif
 
 #ifndef HAVE_SETENV
 # define HAVE_SETENV 1
 #endif
 
 #ifndef HAVE_STRDUP
 # define HAVE_STRDUP 1
 #endif
 
-#ifndef HAVE_STRTOLL
-# define HAVE_STRTOLL 1
-#endif
-
 #ifndef HAVE_SYMLINK
 # define HAVE_SYMLINK 1
 #endif /* !defined HAVE_SYMLINK */
 
 #if !defined HAVE_SYS_STAT_H && defined __has_include
 # if !__has_include()
 #  define HAVE_SYS_STAT_H false
 # endif
 #endif
 #ifndef HAVE_SYS_STAT_H
 # define HAVE_SYS_STAT_H true
 #endif
 
 #if !defined HAVE_UNISTD_H && defined __has_include
 # if !__has_include()
 #  define HAVE_UNISTD_H false
 # endif
 #endif
 #ifndef HAVE_UNISTD_H
 # define HAVE_UNISTD_H true
 #endif
 
 #ifndef NETBSD_INSPIRED
 # define NETBSD_INSPIRED 1
 #endif
 
 #if HAVE_INCOMPATIBLE_CTIME_R
 # define asctime_r _incompatible_asctime_r
 # define ctime_r _incompatible_ctime_r
 #endif /* HAVE_INCOMPATIBLE_CTIME_R */
 
 /* Enable tm_gmtoff, tm_zone, and environ on GNUish systems.  */
 #define _GNU_SOURCE 1
 /* Fix asctime_r on Solaris 11.  */
 #define _POSIX_PTHREAD_SEMANTICS 1
 /* Enable strtoimax on pre-C99 Solaris 11.  */
 #define __EXTENSIONS__ 1
 
 /* On GNUish systems where time_t might be 32 or 64 bits, use 64.
    On these platforms _FILE_OFFSET_BITS must also be 64; otherwise
    setting _TIME_BITS to 64 does not work.  The code does not
    otherwise rely on _FILE_OFFSET_BITS being 64, since it does not
    use off_t or functions like 'stat' that depend on off_t.  */
 #ifndef _FILE_OFFSET_BITS
 # define _FILE_OFFSET_BITS 64
 #endif
 #if !defined _TIME_BITS && _FILE_OFFSET_BITS == 64
 # define _TIME_BITS 64
 #endif
 
 /*
 ** Nested includes
 */
 
 /* Avoid clashes with NetBSD by renaming NetBSD's declarations.
    If defining the 'timezone' variable, avoid a clash with FreeBSD's
    'timezone' function by renaming its declaration.  */
 #define localtime_rz sys_localtime_rz
 #define mktime_z sys_mktime_z
 #define posix2time_z sys_posix2time_z
 #define time2posix_z sys_time2posix_z
 #if defined USG_COMPAT && USG_COMPAT == 2
 # define timezone sys_timezone
 #endif
 #define timezone_t sys_timezone_t
 #define tzalloc sys_tzalloc
 #define tzfree sys_tzfree
 #include 
 #undef localtime_rz
 #undef mktime_z
 #undef posix2time_z
 #undef time2posix_z
 #if defined USG_COMPAT && USG_COMPAT == 2
 # undef timezone
 #endif
 #undef timezone_t
 #undef tzalloc
 #undef tzfree
 
 #include 
 #include 
+#if !PORT_TO_C89
+# include 
+#endif
 #include 	/* for CHAR_BIT et al. */
 #include 
 
 #include 
 
 #ifndef EINVAL
 # define EINVAL ERANGE
 #endif
 
 #ifndef ELOOP
 # define ELOOP EINVAL
 #endif
 #ifndef ENAMETOOLONG
 # define ENAMETOOLONG EINVAL
 #endif
 #ifndef ENOMEM
 # define ENOMEM EINVAL
 #endif
 #ifndef ENOTSUP
 # define ENOTSUP EINVAL
 #endif
 #ifndef EOVERFLOW
 # define EOVERFLOW EINVAL
 #endif
 
 #if HAVE_GETTEXT
 # include 
 #endif /* HAVE_GETTEXT */
 
 #if HAVE_UNISTD_H
 # include  /* for R_OK, and other POSIX goodness */
 #endif /* HAVE_UNISTD_H */
 
 #ifndef HAVE_STRFTIME_L
 # if _POSIX_VERSION < 200809
 #  define HAVE_STRFTIME_L 0
 # else
 #  define HAVE_STRFTIME_L 1
 # endif
 #endif
 
 #ifndef USG_COMPAT
 # ifndef _XOPEN_VERSION
 #  define USG_COMPAT 0
 # else
 #  define USG_COMPAT 1
 # endif
 #endif
 
 #ifndef HAVE_TZNAME
 # if _POSIX_VERSION < 198808 && !USG_COMPAT
 #  define HAVE_TZNAME 0
 # else
 #  define HAVE_TZNAME 1
 # endif
 #endif
 
 #ifndef ALTZONE
 # if defined __sun || defined _M_XENIX
 #  define ALTZONE 1
 # else
 #  define ALTZONE 0
 # endif
 #endif
 
 #ifndef R_OK
 # define R_OK 4
 #endif /* !defined R_OK */
 
+#if PORT_TO_C89
+
 /*
 ** Define HAVE_STDINT_H's default value here, rather than at the
 ** start, since __GLIBC__ and INTMAX_MAX's values depend on
-** previously-included files.  glibc 2.1 and Solaris 10 and later have
+** previously included files.  glibc 2.1 and Solaris 10 and later have
 ** stdint.h, even with pre-C99 compilers.
 */
 #if !defined HAVE_STDINT_H && defined __has_include
 # define HAVE_STDINT_H true /* C23 __has_include implies C99 stdint.h.  */
 #endif
 #ifndef HAVE_STDINT_H
 # define HAVE_STDINT_H \
    (199901 <= __STDC_VERSION__ \
     || 2 < __GLIBC__ + (1 <= __GLIBC_MINOR__) \
     || __CYGWIN__ || INTMAX_MAX)
 #endif /* !defined HAVE_STDINT_H */
 
 #if HAVE_STDINT_H
 # include 
 #endif /* !HAVE_STDINT_H */
 
 #ifndef HAVE_INTTYPES_H
 # define HAVE_INTTYPES_H HAVE_STDINT_H
 #endif
 #if HAVE_INTTYPES_H
 # include 
 #endif
 
 /* Pre-C99 GCC compilers define __LONG_LONG_MAX__ instead of LLONG_MAX.  */
 #if defined __LONG_LONG_MAX__ && !defined __STRICT_ANSI__
 # ifndef LLONG_MAX
 #  define LLONG_MAX __LONG_LONG_MAX__
 # endif
 # ifndef LLONG_MIN
 #  define LLONG_MIN (-1 - LLONG_MAX)
 # endif
 # ifndef ULLONG_MAX
 #  define ULLONG_MAX (LLONG_MAX * 2ull + 1)
 # endif
 #endif
 
 #ifndef INT_FAST64_MAX
 # if 1 <= LONG_MAX >> 31 >> 31
 typedef long int_fast64_t;
 #  define INT_FAST64_MIN LONG_MIN
 #  define INT_FAST64_MAX LONG_MAX
 # else
 /* If this fails, compile with -DHAVE_STDINT_H or with a better compiler.  */
 typedef long long int_fast64_t;
 #  define INT_FAST64_MIN LLONG_MIN
 #  define INT_FAST64_MAX LLONG_MAX
 # endif
 #endif
 
 #ifndef PRIdFAST64
 # if INT_FAST64_MAX == LONG_MAX
 #  define PRIdFAST64 "ld"
 # else
 #  define PRIdFAST64 "lld"
 # endif
 #endif
 
 #ifndef SCNdFAST64
 # define SCNdFAST64 PRIdFAST64
 #endif
 
 #ifndef INT_FAST32_MAX
 # if INT_MAX >> 31 == 0
 typedef long int_fast32_t;
 #  define INT_FAST32_MAX LONG_MAX
 #  define INT_FAST32_MIN LONG_MIN
 # else
 typedef int int_fast32_t;
 #  define INT_FAST32_MAX INT_MAX
 #  define INT_FAST32_MIN INT_MIN
 # endif
 #endif
 
 #ifndef INTMAX_MAX
 # ifdef LLONG_MAX
 typedef long long intmax_t;
+#  ifndef HAVE_STRTOLL
+#   define HAVE_STRTOLL true
+#  endif
 #  if HAVE_STRTOLL
 #   define strtoimax strtoll
 #  endif
 #  define INTMAX_MAX LLONG_MAX
 #  define INTMAX_MIN LLONG_MIN
 # else
 typedef long intmax_t;
 #  define INTMAX_MAX LONG_MAX
 #  define INTMAX_MIN LONG_MIN
 # endif
 # ifndef strtoimax
 #  define strtoimax strtol
 # endif
 #endif
 
 #ifndef PRIdMAX
 # if INTMAX_MAX == LLONG_MAX
 #  define PRIdMAX "lld"
 # else
 #  define PRIdMAX "ld"
 # endif
 #endif
 
 #ifndef PTRDIFF_MAX
 # define PTRDIFF_MAX MAXVAL(ptrdiff_t, TYPE_BIT(ptrdiff_t))
 #endif
 
 #ifndef UINT_FAST32_MAX
 typedef unsigned long uint_fast32_t;
 #endif
 
 #ifndef UINT_FAST64_MAX
 # if 3 <= ULONG_MAX >> 31 >> 31
 typedef unsigned long uint_fast64_t;
 #  define UINT_FAST64_MAX ULONG_MAX
 # else
 /* If this fails, compile with -DHAVE_STDINT_H or with a better compiler.  */
 typedef unsigned long long uint_fast64_t;
 #  define UINT_FAST64_MAX ULLONG_MAX
 # endif
 #endif
 
 #ifndef UINTMAX_MAX
 # ifdef ULLONG_MAX
 typedef unsigned long long uintmax_t;
+#  define UINTMAX_MAX ULLONG_MAX
 # else
 typedef unsigned long uintmax_t;
+#  define UINTMAX_MAX ULONG_MAX
 # endif
 #endif
 
 #ifndef PRIuMAX
 # ifdef ULLONG_MAX
 #  define PRIuMAX "llu"
 # else
 #  define PRIuMAX "lu"
 # endif
 #endif
 
 #ifndef SIZE_MAX
 # define SIZE_MAX ((size_t) -1)
 #endif
 
+#endif /* PORT_TO_C89 */
+
+/* The maximum size of any created object, as a signed integer.
+   Although the C standard does not outright prohibit larger objects,
+   behavior is undefined if the result of pointer subtraction does not
+   fit into ptrdiff_t, and the code assumes in several places that
+   pointer subtraction works.  As a practical matter it's OK to not
+   support objects larger than this.  */
+#define INDEX_MAX ((ptrdiff_t) min(PTRDIFF_MAX, SIZE_MAX))
+
 /* Support ckd_add, ckd_sub, ckd_mul on C23 or recent-enough GCC-like
    hosts, unless compiled with -DHAVE_STDCKDINT_H=0 or with pre-C23 EDG.  */
 #if !defined HAVE_STDCKDINT_H && defined __has_include
 # if __has_include()
 #  define HAVE_STDCKDINT_H true
 # endif
 #endif
 #ifdef HAVE_STDCKDINT_H
 # if HAVE_STDCKDINT_H
 #  include 
 # endif
 #elif defined __EDG__
 /* Do nothing, to work around EDG bug .  */
 #elif defined __has_builtin
 # if __has_builtin(__builtin_add_overflow)
 #  define ckd_add(r, a, b) __builtin_add_overflow(a, b, r)
 # endif
 # if __has_builtin(__builtin_sub_overflow)
 #  define ckd_sub(r, a, b) __builtin_sub_overflow(a, b, r)
 # endif
 # if __has_builtin(__builtin_mul_overflow)
 #  define ckd_mul(r, a, b) __builtin_mul_overflow(a, b, r)
 # endif
 #elif 7 <= __GNUC__
 # define ckd_add(r, a, b) __builtin_add_overflow(a, b, r)
 # define ckd_sub(r, a, b) __builtin_sub_overflow(a, b, r)
 # define ckd_mul(r, a, b) __builtin_mul_overflow(a, b, r)
 #endif
 
 #if 3 <= __GNUC__
 # define ATTRIBUTE_MALLOC __attribute__((malloc))
 # define ATTRIBUTE_FORMAT(spec) __attribute__((format spec))
 #else
 # define ATTRIBUTE_MALLOC /* empty */
 # define ATTRIBUTE_FORMAT(spec) /* empty */
 #endif
 
 #if (defined __has_c_attribute \
      && (202311 <= __STDC_VERSION__ || !defined __STRICT_ANSI__))
-# define HAVE_HAS_C_ATTRIBUTE true
+# define HAVE___HAS_C_ATTRIBUTE true
 #else
-# define HAVE_HAS_C_ATTRIBUTE false
+# define HAVE___HAS_C_ATTRIBUTE false
+#endif
+
+#if HAVE___HAS_C_ATTRIBUTE
+# if __has_c_attribute(deprecated)
+#  define ATTRIBUTE_DEPRECATED [[deprecated]]
+# endif
+#endif
+#ifndef ATTRIBUTE_DEPRECATED
+# if 3 < __GNUC__ + (2 <= __GNUC_MINOR__)
+#  define ATTRIBUTE_DEPRECATED __attribute__((deprecated))
+# else
+#  define ATTRIBUTE_DEPRECATED /* empty */
+# endif
 #endif
 
-#if HAVE_HAS_C_ATTRIBUTE
+#if HAVE___HAS_C_ATTRIBUTE
 # if __has_c_attribute(fallthrough)
 #  define ATTRIBUTE_FALLTHROUGH [[fallthrough]]
 # endif
 #endif
 #ifndef ATTRIBUTE_FALLTHROUGH
 # if 7 <= __GNUC__
 #  define ATTRIBUTE_FALLTHROUGH __attribute__((fallthrough))
 # else
 #  define ATTRIBUTE_FALLTHROUGH ((void) 0)
 # endif
 #endif
 
-#if HAVE_HAS_C_ATTRIBUTE
+#if HAVE___HAS_C_ATTRIBUTE
 # if __has_c_attribute(maybe_unused)
 #  define ATTRIBUTE_MAYBE_UNUSED [[maybe_unused]]
 # endif
 #endif
 #ifndef ATTRIBUTE_MAYBE_UNUSED
 # if 2 < __GNUC__ + (7 <= __GNUC_MINOR__)
 #  define ATTRIBUTE_MAYBE_UNUSED __attribute__((unused))
 # else
 #  define ATTRIBUTE_MAYBE_UNUSED /* empty */
 # endif
 #endif
 
-#if HAVE_HAS_C_ATTRIBUTE
+#if HAVE___HAS_C_ATTRIBUTE
 # if __has_c_attribute(noreturn)
 #  define ATTRIBUTE_NORETURN [[noreturn]]
 # endif
 #endif
 #ifndef ATTRIBUTE_NORETURN
 # if 201112 <= __STDC_VERSION__
 #  define ATTRIBUTE_NORETURN _Noreturn
 # elif 2 < __GNUC__ + (8 <= __GNUC_MINOR__)
 #  define ATTRIBUTE_NORETURN __attribute__((noreturn))
 # else
 #  define ATTRIBUTE_NORETURN /* empty */
 # endif
 #endif
 
-#if HAVE_HAS_C_ATTRIBUTE
+#if HAVE___HAS_C_ATTRIBUTE
 # if __has_c_attribute(reproducible)
 #  define ATTRIBUTE_REPRODUCIBLE [[reproducible]]
 # endif
 #endif
 #ifndef ATTRIBUTE_REPRODUCIBLE
 # if 3 <= __GNUC__
 #  define ATTRIBUTE_REPRODUCIBLE __attribute__((pure))
 # else
 #  define ATTRIBUTE_REPRODUCIBLE /* empty */
 # endif
 #endif
 
-#if HAVE_HAS_C_ATTRIBUTE
+#if HAVE___HAS_C_ATTRIBUTE
 # if __has_c_attribute(unsequenced)
 #  define ATTRIBUTE_UNSEQUENCED [[unsequenced]]
 # endif
 #endif
 #ifndef ATTRIBUTE_UNSEQUENCED
 # if 3 <= __GNUC__
 #  define ATTRIBUTE_UNSEQUENCED __attribute__((const))
 # else
 #  define ATTRIBUTE_UNSEQUENCED /* empty */
 # endif
 #endif
 
-#if __STDC_VERSION__ < 199901 && !defined restrict
+#if (__STDC_VERSION__ < 199901 && !defined restrict \
+     && (PORT_TO_C89 || defined _MSC_VER))
 # define restrict /* empty */
 #endif
 
 /*
 ** Workarounds for compilers/systems.
 */
 
 #ifndef EPOCH_LOCAL
 # define EPOCH_LOCAL 0
 #endif
 #ifndef EPOCH_OFFSET
 # define EPOCH_OFFSET 0
 #endif
 #ifndef RESERVE_STD_EXT_IDS
 # define RESERVE_STD_EXT_IDS 0
 #endif
 
 /* If standard C identifiers with external linkage (e.g., localtime)
    are reserved and are not already being renamed anyway, rename them
    as if compiling with '-Dtime_tz=time_t'.  */
 #if !defined time_tz && RESERVE_STD_EXT_IDS && USE_LTZ
 # define time_tz time_t
 #endif
 
 /*
 ** Compile with -Dtime_tz=T to build the tz package with a private
 ** time_t type equivalent to T rather than the system-supplied time_t.
 ** This debugging feature can test unusual design decisions
 ** (e.g., time_t wider than 'long', or unsigned time_t) even on
 ** typical platforms.
 */
 #if defined time_tz || EPOCH_LOCAL || EPOCH_OFFSET != 0
 # define TZ_TIME_T 1
 #else
 # define TZ_TIME_T 0
 #endif
 
 #if defined LOCALTIME_IMPLEMENTATION && TZ_TIME_T
 static time_t sys_time(time_t *x) { return time(x); }
 #endif
 
 #if TZ_TIME_T
 
 typedef time_tz tz_time_t;
 
 # undef  asctime
 # define asctime tz_asctime
 # undef  asctime_r
 # define asctime_r tz_asctime_r
 # undef  ctime
 # define ctime tz_ctime
 # undef  ctime_r
 # define ctime_r tz_ctime_r
 # undef  difftime
 # define difftime tz_difftime
 # undef  gmtime
 # define gmtime tz_gmtime
 # undef  gmtime_r
 # define gmtime_r tz_gmtime_r
 # undef  localtime
 # define localtime tz_localtime
 # undef  localtime_r
 # define localtime_r tz_localtime_r
 # undef  localtime_rz
 # define localtime_rz tz_localtime_rz
 # undef  mktime
 # define mktime tz_mktime
 # undef  mktime_z
 # define mktime_z tz_mktime_z
 # undef  offtime
 # define offtime tz_offtime
+# undef  offtime_r
+# define offtime_r tz_offtime_r
 # undef  posix2time
 # define posix2time tz_posix2time
 # undef  posix2time_z
 # define posix2time_z tz_posix2time_z
 # undef  strftime
 # define strftime tz_strftime
 # undef  time
 # define time tz_time
 # undef  time2posix
 # define time2posix tz_time2posix
 # undef  time2posix_z
 # define time2posix_z tz_time2posix_z
 # undef  time_t
 # define time_t tz_time_t
 # undef  timegm
 # define timegm tz_timegm
 # undef  timelocal
 # define timelocal tz_timelocal
 # undef  timeoff
 # define timeoff tz_timeoff
 # undef  tzalloc
 # define tzalloc tz_tzalloc
 # undef  tzfree
 # define tzfree tz_tzfree
 # undef  tzset
 # define tzset tz_tzset
 # if HAVE_STRFTIME_L
 #  undef  strftime_l
 #  define strftime_l tz_strftime_l
 # endif
 # if HAVE_TZNAME
 #  undef  tzname
 #  define tzname tz_tzname
 # endif
 # if USG_COMPAT
 #  undef  daylight
 #  define daylight tz_daylight
 #  undef  timezone
 #  define timezone tz_timezone
 # endif
 # if ALTZONE
 #  undef  altzone
 #  define altzone tz_altzone
 # endif
 
-char *asctime(struct tm const *);
+# if __STDC_VERSION__ < 202311
+#  define DEPRECATED_IN_C23 /* empty */
+# else
+#  define DEPRECATED_IN_C23 ATTRIBUTE_DEPRECATED
+# endif
+DEPRECATED_IN_C23 char *asctime(struct tm const *);
 char *asctime_r(struct tm const *restrict, char *restrict);
-char *ctime(time_t const *);
+DEPRECATED_IN_C23 char *ctime(time_t const *);
 char *ctime_r(time_t const *, char *);
-double difftime(time_t, time_t) ATTRIBUTE_UNSEQUENCED;
+ATTRIBUTE_UNSEQUENCED double difftime(time_t, time_t);
 size_t strftime(char *restrict, size_t, char const *restrict,
 		struct tm const *restrict);
 # if HAVE_STRFTIME_L
 size_t strftime_l(char *restrict, size_t, char const *restrict,
 		  struct tm const *restrict, locale_t);
 # endif
 struct tm *gmtime(time_t const *);
 struct tm *gmtime_r(time_t const *restrict, struct tm *restrict);
 struct tm *localtime(time_t const *);
 struct tm *localtime_r(time_t const *restrict, struct tm *restrict);
 time_t mktime(struct tm *);
 time_t time(time_t *);
 time_t timegm(struct tm *);
 void tzset(void);
 #endif
 
 #ifndef HAVE_DECL_TIMEGM
 # if (202311 <= __STDC_VERSION__ \
       || defined __GLIBC__ || defined __tm_zone /* musl */ \
       || defined __FreeBSD__ || defined __NetBSD__ || defined __OpenBSD__ \
       || (defined __APPLE__ && defined __MACH__))
 #  define HAVE_DECL_TIMEGM true
 # else
 #  define HAVE_DECL_TIMEGM false
 # endif
 #endif
 #if !HAVE_DECL_TIMEGM && !defined timegm
 time_t timegm(struct tm *);
 #endif
 
 #if !HAVE_DECL_ASCTIME_R && !defined asctime_r
 extern char *asctime_r(struct tm const *restrict, char *restrict);
 #endif
 
 #ifndef HAVE_DECL_ENVIRON
 # if defined environ || defined __USE_GNU
 #  define HAVE_DECL_ENVIRON 1
 # else
 #  define HAVE_DECL_ENVIRON 0
 # endif
 #endif
 
 #if !HAVE_DECL_ENVIRON
 extern char **environ;
 #endif
 
 #if 2 <= HAVE_TZNAME + (TZ_TIME_T || !HAVE_POSIX_DECLS)
 extern char *tzname[];
 #endif
 #if 2 <= USG_COMPAT + (TZ_TIME_T || !HAVE_POSIX_DECLS)
 extern long timezone;
 extern int daylight;
 #endif
 #if 2 <= ALTZONE + (TZ_TIME_T || !HAVE_POSIX_DECLS)
 extern long altzone;
 #endif
 
 /*
 ** The STD_INSPIRED functions are similar, but most also need
 ** declarations if time_tz is defined.
 */
 
-#ifdef STD_INSPIRED
+#ifndef STD_INSPIRED
+# define STD_INSPIRED 0
+#endif
+#if STD_INSPIRED
 # if TZ_TIME_T || !defined offtime
 struct tm *offtime(time_t const *, long);
 # endif
+# if TZ_TIME_T || !defined offtime_r
+struct tm *offtime_r(time_t const *, long, struct tm *);
+# endif
 # if TZ_TIME_T || !defined timelocal
 time_t timelocal(struct tm *);
 # endif
 # if TZ_TIME_T || !defined timeoff
 time_t timeoff(struct tm *, long);
 # endif
 # if TZ_TIME_T || !defined time2posix
 time_t time2posix(time_t);
 # endif
 # if TZ_TIME_T || !defined posix2time
 time_t posix2time(time_t);
 # endif
 #endif
 
 /* Infer TM_ZONE on systems where this information is known, but suppress
    guessing if NO_TM_ZONE is defined.  Similarly for TM_GMTOFF.  */
 #if (defined __GLIBC__ \
      || defined __tm_zone /* musl */ \
      || defined __FreeBSD__ || defined __NetBSD__ || defined __OpenBSD__ \
      || (defined __APPLE__ && defined __MACH__))
 # if !defined TM_GMTOFF && !defined NO_TM_GMTOFF
 #  define TM_GMTOFF tm_gmtoff
 # endif
 # if !defined TM_ZONE && !defined NO_TM_ZONE
 #  define TM_ZONE tm_zone
 # endif
 #endif
 
 /*
 ** Define functions that are ABI compatible with NetBSD but have
 ** better prototypes.  NetBSD 6.1.4 defines a pointer type timezone_t
 ** and labors under the misconception that 'const timezone_t' is a
 ** pointer to a constant.  This use of 'const' is ineffective, so it
 ** is not done here.  What we call 'struct state' NetBSD calls
 ** 'struct __state', but this is a private name so it doesn't matter.
 */
 #if NETBSD_INSPIRED
 typedef struct state *timezone_t;
 struct tm *localtime_rz(timezone_t restrict, time_t const *restrict,
 			struct tm *restrict);
 time_t mktime_z(timezone_t restrict, struct tm *restrict);
 timezone_t tzalloc(char const *);
 void tzfree(timezone_t);
-# ifdef STD_INSPIRED
+# if STD_INSPIRED
 #  if TZ_TIME_T || !defined posix2time_z
-time_t posix2time_z(timezone_t, time_t) ATTRIBUTE_REPRODUCIBLE;
+ATTRIBUTE_REPRODUCIBLE time_t posix2time_z(timezone_t, time_t);
 #  endif
 #  if TZ_TIME_T || !defined time2posix_z
-time_t time2posix_z(timezone_t, time_t) ATTRIBUTE_REPRODUCIBLE;
+ATTRIBUTE_REPRODUCIBLE time_t time2posix_z(timezone_t, time_t);
 #  endif
 # endif
 #endif
 
 /*
 ** Finally, some convenience items.
 */
 
-#define TYPE_BIT(type)	(sizeof(type) * CHAR_BIT)
+#define TYPE_BIT(type) (CHAR_BIT * (ptrdiff_t) sizeof(type))
 #define TYPE_SIGNED(type) (((type) -1) < 0)
 #define TWOS_COMPLEMENT(t) ((t) ~ (t) 0 < 0)
 
 /* Minimum and maximum of two values.  Use lower case to avoid
    naming clashes with standard include files.  */
 #define max(a, b) ((a) > (b) ? (a) : (b))
 #define min(a, b) ((a) < (b) ? (a) : (b))
 
 /* Max and min values of the integer type T, of which only the bottom
    B bits are used, and where the highest-order used bit is considered
    to be a sign bit if T is signed.  */
 #define MAXVAL(t, b)						\
   ((t) (((t) 1 << ((b) - 1 - TYPE_SIGNED(t)))			\
 	- 1 + ((t) 1 << ((b) - 1 - TYPE_SIGNED(t)))))
 #define MINVAL(t, b)						\
   ((t) (TYPE_SIGNED(t) ? - TWOS_COMPLEMENT(t) - MAXVAL(t, b) : 0))
 
 /* The extreme time values, assuming no padding.  */
 #define TIME_T_MIN_NO_PADDING MINVAL(time_t, TYPE_BIT(time_t))
 #define TIME_T_MAX_NO_PADDING MAXVAL(time_t, TYPE_BIT(time_t))
 
 /* The extreme time values.  These are macros, not constants, so that
    any portability problems occur only when compiling .c files that use
    the macros, which is safer for applications that need only zdump and zic.
    This implementation assumes no padding if time_t is signed and
    either the compiler lacks support for _Generic or time_t is not one
    of the standard signed integer types.  */
-#if HAVE_GENERIC
+#if HAVE__GENERIC
 # define TIME_T_MIN \
     _Generic((time_t) 0, \
 	     signed char: SCHAR_MIN, short: SHRT_MIN, \
 	     int: INT_MIN, long: LONG_MIN, long long: LLONG_MIN, \
 	     default: TIME_T_MIN_NO_PADDING)
 # define TIME_T_MAX \
     (TYPE_SIGNED(time_t) \
      ? _Generic((time_t) 0, \
 		signed char: SCHAR_MAX, short: SHRT_MAX, \
 		int: INT_MAX, long: LONG_MAX, long long: LLONG_MAX, \
 		default: TIME_T_MAX_NO_PADDING)			    \
      : (time_t) -1)
+enum { SIGNED_PADDING_CHECK_NEEDED
+         = _Generic((time_t) 0,
+		    signed char: false, short: false,
+		    int: false, long: false, long long: false,
+		    default: true) };
 #else
 # define TIME_T_MIN TIME_T_MIN_NO_PADDING
 # define TIME_T_MAX TIME_T_MAX_NO_PADDING
+enum { SIGNED_PADDING_CHECK_NEEDED = true };
 #endif
+/* Try to check the padding assumptions.  Although TIME_T_MAX and the
+   following check can both have undefined behavior on oddball
+   platforms due to shifts exceeding widths of signed integers, these
+   platforms' compilers are likely to diagnose these issues in integer
+   constant expressions, so it shouldn't hurt to check statically.  */
+static_assert(! TYPE_SIGNED(time_t) || ! SIGNED_PADDING_CHECK_NEEDED
+	      || TIME_T_MAX >> (TYPE_BIT(time_t) - 2) == 1);
 
 /*
 ** 302 / 1000 is log10(2.0) rounded up.
 ** Subtract one for the sign bit if the type is signed;
 ** add one for integer division truncation;
 ** add one more for a minus sign if the type is signed.
 */
 #define INT_STRLEN_MAXIMUM(type) \
 	((TYPE_BIT(type) - TYPE_SIGNED(type)) * 302 / 1000 + \
 	1 + TYPE_SIGNED(type))
 
 /*
 ** INITIALIZE(x)
 */
 
 #ifdef GCC_LINT
 # define INITIALIZE(x)	((x) = 0)
 #else
 # define INITIALIZE(x)
 #endif
 
 /* Whether memory access must strictly follow the C standard.
    If 0, it's OK to read uninitialized storage so long as the value is
    not relied upon.  Defining it to 0 lets mktime access parts of
    struct tm that might be uninitialized, as a heuristic when the
    standard doesn't say what to return and when tm_gmtoff can help
    mktime likely infer a better value.  */
 #ifndef UNINIT_TRAP
 # define UNINIT_TRAP 0
 #endif
 
 #ifdef DEBUG
 # undef unreachable
 # define unreachable() abort()
 #elif !defined unreachable
 # ifdef __has_builtin
 #  if __has_builtin(__builtin_unreachable)
 #   define unreachable() __builtin_unreachable()
 #  endif
 # elif 4 < __GNUC__ + (5 <= __GNUC_MINOR__)
 #  define unreachable() __builtin_unreachable()
 # endif
 # ifndef unreachable
 #  define unreachable() ((void) 0)
 # endif
 #endif
 
 /*
 ** For the benefit of GNU folk...
 ** '_(MSGID)' uses the current locale's message library string for MSGID.
 ** The default is to use gettext if available, and use MSGID otherwise.
 */
 
 #if HAVE_GETTEXT
 #define _(msgid) gettext(msgid)
 #else /* !HAVE_GETTEXT */
 #define _(msgid) msgid
 #endif /* !HAVE_GETTEXT */
 
 #if !defined TZ_DOMAIN && defined HAVE_GETTEXT
 # define TZ_DOMAIN "tz"
 #endif
 
 #if HAVE_INCOMPATIBLE_CTIME_R
 #undef asctime_r
 #undef ctime_r
-char *asctime_r(struct tm const *, char *);
+char *asctime_r(struct tm const *restrict, char *restrict);
 char *ctime_r(time_t const *, char *);
 #endif /* HAVE_INCOMPATIBLE_CTIME_R */
 
 /* Handy macros that are independent of tzfile implementation.  */
 
 enum {
   SECSPERMIN = 60,
   MINSPERHOUR = 60,
   SECSPERHOUR = SECSPERMIN * MINSPERHOUR,
   HOURSPERDAY = 24,
   DAYSPERWEEK = 7,
   DAYSPERNYEAR = 365,
   DAYSPERLYEAR = DAYSPERNYEAR + 1,
   MONSPERYEAR = 12,
   YEARSPERREPEAT = 400	/* years before a Gregorian repeat */
 };
 
 #define SECSPERDAY	((int_fast32_t) SECSPERHOUR * HOURSPERDAY)
 
 #define DAYSPERREPEAT		((int_fast32_t) 400 * 365 + 100 - 4 + 1)
 #define SECSPERREPEAT		((int_fast64_t) DAYSPERREPEAT * SECSPERDAY)
 #define AVGSECSPERYEAR		(SECSPERREPEAT / YEARSPERREPEAT)
 
 enum {
   TM_SUNDAY,
   TM_MONDAY,
   TM_TUESDAY,
   TM_WEDNESDAY,
   TM_THURSDAY,
   TM_FRIDAY,
   TM_SATURDAY
 };
 
 enum {
   TM_JANUARY,
   TM_FEBRUARY,
   TM_MARCH,
   TM_APRIL,
   TM_MAY,
   TM_JUNE,
   TM_JULY,
   TM_AUGUST,
   TM_SEPTEMBER,
   TM_OCTOBER,
   TM_NOVEMBER,
   TM_DECEMBER
 };
 
 enum {
   TM_YEAR_BASE = 1900,
   TM_WDAY_BASE = TM_MONDAY,
   EPOCH_YEAR = 1970,
   EPOCH_WDAY = TM_THURSDAY
 };
 
 #define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0))
 
 /*
 ** Since everything in isleap is modulo 400 (or a factor of 400), we know that
 **	isleap(y) == isleap(y % 400)
 ** and so
 **	isleap(a + b) == isleap((a + b) % 400)
 ** or
 **	isleap(a + b) == isleap(a % 400 + b % 400)
 ** This is true even if % means modulo rather than Fortran remainder
 ** (which is allowed by C89 but not by C99 or later).
 ** We use this to avoid addition overflow problems.
 */
 
 #define isleap_sum(a, b)	isleap((a) % 400 + (b) % 400)
 
 #endif /* !defined PRIVATE_H */
diff --git a/contrib/tzcode/strftime.c b/contrib/tzcode/strftime.c
index b23b6101b150..df169830f9ef 100644
--- a/contrib/tzcode/strftime.c
+++ b/contrib/tzcode/strftime.c
@@ -1,657 +1,659 @@
 /* Convert a broken-down timestamp to a string.  */
 
 /* Copyright 1989 The Regents of the University of California.
    All rights reserved.
 
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions
    are met:
    1. Redistributions of source code must retain the above copyright
       notice, this list of conditions and the following disclaimer.
    2. Redistributions in binary form must reproduce the above copyright
       notice, this list of conditions and the following disclaimer in the
       documentation and/or other materials provided with the distribution.
    3. Neither the name of the University nor the names of its contributors
       may be used to endorse or promote products derived from this software
       without specific prior written permission.
 
    THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS" AND
    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
    ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
    OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
    SUCH DAMAGE.  */
 
 /*
 ** Based on the UCB version with the copyright notice appearing above.
 **
 ** This is ANSIish only when "multibyte character == plain character".
 */
 
 #include "private.h"
 
 #include 
 #include 
 #include 
 
 #ifndef DEPRECATE_TWO_DIGIT_YEARS
 # define DEPRECATE_TWO_DIGIT_YEARS false
 #endif
 
 struct lc_time_T {
 	const char *	mon[MONSPERYEAR];
 	const char *	month[MONSPERYEAR];
 	const char *	wday[DAYSPERWEEK];
 	const char *	weekday[DAYSPERWEEK];
 	const char *	X_fmt;
 	const char *	x_fmt;
 	const char *	c_fmt;
 	const char *	am;
 	const char *	pm;
 	const char *	date_fmt;
 };
 
 static const struct lc_time_T	C_time_locale = {
 	{
 		"Jan", "Feb", "Mar", "Apr", "May", "Jun",
 		"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
 	}, {
 		"January", "February", "March", "April", "May", "June",
 		"July", "August", "September", "October", "November", "December"
 	}, {
 		"Sun", "Mon", "Tue", "Wed",
 		"Thu", "Fri", "Sat"
 	}, {
 		"Sunday", "Monday", "Tuesday", "Wednesday",
 		"Thursday", "Friday", "Saturday"
 	},
 
 	/* X_fmt */
 	"%H:%M:%S",
 
 	/*
 	** x_fmt
 	** C99 and later require this format.
 	** Using just numbers (as here) makes Quakers happier;
 	** it's also compatible with SVR4.
 	*/
 	"%m/%d/%y",
 
 	/*
 	** c_fmt
 	** C99 and later require this format.
 	** Previously this code used "%D %X", but we now conform to C99.
 	** Note that
 	**	"%a %b %d %H:%M:%S %Y"
 	** is used by Solaris 2.3.
 	*/
 	"%a %b %e %T %Y",
 
 	/* am */
 	"AM",
 
 	/* pm */
 	"PM",
 
 	/* date_fmt */
 	"%a %b %e %H:%M:%S %Z %Y"
 };
 
 enum warn { IN_NONE, IN_SOME, IN_THIS, IN_ALL };
 
 static char *	_add(const char *, char *, const char *);
 static char *	_conv(int, const char *, char *, const char *);
 static char *	_fmt(const char *, const struct tm *, char *, const char *,
 		     enum warn *);
 static char *	_yconv(int, int, bool, bool, char *, char const *);
 
 #ifndef YEAR_2000_NAME
 # define YEAR_2000_NAME "CHECK_STRFTIME_FORMATS_FOR_TWO_DIGIT_YEARS"
 #endif /* !defined YEAR_2000_NAME */
 
 #if HAVE_STRFTIME_L
 size_t
-strftime_l(char *s, size_t maxsize, char const *format, struct tm const *t,
+strftime_l(char *restrict s, size_t maxsize, char const *restrict format,
+	   struct tm const *restrict t,
 	   ATTRIBUTE_MAYBE_UNUSED locale_t locale)
 {
   /* Just call strftime, as only the C locale is supported.  */
   return strftime(s, maxsize, format, t);
 }
 #endif
 
 size_t
-strftime(char *s, size_t maxsize, const char *format, const struct tm *t)
+strftime(char *restrict s, size_t maxsize, char const *restrict format,
+	 struct tm const *restrict t)
 {
 	char *	p;
 	int saved_errno = errno;
 	enum warn warn = IN_NONE;
 
 	tzset();
 	p = _fmt(format, t, s, s + maxsize, &warn);
 	if (!p) {
 	  errno = EOVERFLOW;
 	  return 0;
 	}
 	if (DEPRECATE_TWO_DIGIT_YEARS
 	    && warn != IN_NONE && getenv(YEAR_2000_NAME)) {
 		fprintf(stderr, "\n");
 		fprintf(stderr, "strftime format \"%s\" ", format);
 		fprintf(stderr, "yields only two digits of years in ");
 		if (warn == IN_SOME)
 			fprintf(stderr, "some locales");
 		else if (warn == IN_THIS)
 			fprintf(stderr, "the current locale");
 		else	fprintf(stderr, "all locales");
 		fprintf(stderr, "\n");
 	}
 	if (p == s + maxsize) {
 		errno = ERANGE;
 		return 0;
 	}
 	*p = '\0';
 	errno = saved_errno;
 	return p - s;
 }
 
 static char *
 _fmt(const char *format, const struct tm *t, char *pt,
      const char *ptlim, enum warn *warnp)
 {
 	struct lc_time_T const *Locale = &C_time_locale;
 
 	for ( ; *format; ++format) {
 		if (*format == '%') {
 label:
 			switch (*++format) {
 			case '\0':
 				--format;
 				break;
 			case 'A':
 				pt = _add((t->tm_wday < 0 ||
 					t->tm_wday >= DAYSPERWEEK) ?
 					"?" : Locale->weekday[t->tm_wday],
 					pt, ptlim);
 				continue;
 			case 'a':
 				pt = _add((t->tm_wday < 0 ||
 					t->tm_wday >= DAYSPERWEEK) ?
 					"?" : Locale->wday[t->tm_wday],
 					pt, ptlim);
 				continue;
 			case 'B':
 				pt = _add((t->tm_mon < 0 ||
 					t->tm_mon >= MONSPERYEAR) ?
 					"?" : Locale->month[t->tm_mon],
 					pt, ptlim);
 				continue;
 			case 'b':
 			case 'h':
 				pt = _add((t->tm_mon < 0 ||
 					t->tm_mon >= MONSPERYEAR) ?
 					"?" : Locale->mon[t->tm_mon],
 					pt, ptlim);
 				continue;
 			case 'C':
 				/*
 				** %C used to do a...
 				**	_fmt("%a %b %e %X %Y", t);
 				** ...whereas now POSIX 1003.2 calls for
 				** something completely different.
 				** (ado, 1993-05-24)
 				*/
 				pt = _yconv(t->tm_year, TM_YEAR_BASE,
 					    true, false, pt, ptlim);
 				continue;
 			case 'c':
 				{
 				enum warn warn2 = IN_SOME;
 
 				pt = _fmt(Locale->c_fmt, t, pt, ptlim, &warn2);
 				if (warn2 == IN_ALL)
 					warn2 = IN_THIS;
 				if (warn2 > *warnp)
 					*warnp = warn2;
 				}
 				continue;
 			case 'D':
 				pt = _fmt("%m/%d/%y", t, pt, ptlim, warnp);
 				continue;
 			case 'd':
 				pt = _conv(t->tm_mday, "%02d", pt, ptlim);
 				continue;
 			case 'E':
 			case 'O':
 				/*
 				** Locale modifiers of C99 and later.
 				** The sequences
 				**	%Ec %EC %Ex %EX %Ey %EY
 				**	%Od %oe %OH %OI %Om %OM
 				**	%OS %Ou %OU %OV %Ow %OW %Oy
 				** are supposed to provide alternative
 				** representations.
 				*/
 				goto label;
 			case 'e':
 				pt = _conv(t->tm_mday, "%2d", pt, ptlim);
 				continue;
 			case 'F':
 				pt = _fmt("%Y-%m-%d", t, pt, ptlim, warnp);
 				continue;
 			case 'H':
 				pt = _conv(t->tm_hour, "%02d", pt, ptlim);
 				continue;
 			case 'I':
 				pt = _conv((t->tm_hour % 12) ?
 					(t->tm_hour % 12) : 12,
 					"%02d", pt, ptlim);
 				continue;
 			case 'j':
 				pt = _conv(t->tm_yday + 1, "%03d", pt, ptlim);
 				continue;
 			case 'k':
 				/*
 				** This used to be...
 				**	_conv(t->tm_hour % 12 ?
 				**		t->tm_hour % 12 : 12, 2, ' ');
 				** ...and has been changed to the below to
 				** match SunOS 4.1.1 and Arnold Robbins'
 				** strftime version 3.0. That is, "%k" and
 				** "%l" have been swapped.
 				** (ado, 1993-05-24)
 				*/
 				pt = _conv(t->tm_hour, "%2d", pt, ptlim);
 				continue;
 #ifdef KITCHEN_SINK
 			case 'K':
 				/*
 				** After all this time, still unclaimed!
 				*/
 				pt = _add("kitchen sink", pt, ptlim);
 				continue;
 #endif /* defined KITCHEN_SINK */
 			case 'l':
 				/*
 				** This used to be...
 				**	_conv(t->tm_hour, 2, ' ');
 				** ...and has been changed to the below to
 				** match SunOS 4.1.1 and Arnold Robbin's
 				** strftime version 3.0. That is, "%k" and
 				** "%l" have been swapped.
 				** (ado, 1993-05-24)
 				*/
 				pt = _conv((t->tm_hour % 12) ?
 					(t->tm_hour % 12) : 12,
 					"%2d", pt, ptlim);
 				continue;
 			case 'M':
 				pt = _conv(t->tm_min, "%02d", pt, ptlim);
 				continue;
 			case 'm':
 				pt = _conv(t->tm_mon + 1, "%02d", pt, ptlim);
 				continue;
 			case 'n':
 				pt = _add("\n", pt, ptlim);
 				continue;
 			case 'p':
 				pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ?
 					Locale->pm :
 					Locale->am,
 					pt, ptlim);
 				continue;
 			case 'R':
 				pt = _fmt("%H:%M", t, pt, ptlim, warnp);
 				continue;
 			case 'r':
 				pt = _fmt("%I:%M:%S %p", t, pt, ptlim, warnp);
 				continue;
 			case 'S':
 				pt = _conv(t->tm_sec, "%02d", pt, ptlim);
 				continue;
 			case 's':
 				{
 					struct tm	tm;
 					char		buf[INT_STRLEN_MAXIMUM(
 								time_t) + 1];
 					time_t		mkt;
 
 					tm.tm_sec = t->tm_sec;
 					tm.tm_min = t->tm_min;
 					tm.tm_hour = t->tm_hour;
 					tm.tm_mday = t->tm_mday;
 					tm.tm_mon = t->tm_mon;
 					tm.tm_year = t->tm_year;
 					tm.tm_isdst = t->tm_isdst;
 #if defined TM_GMTOFF && ! UNINIT_TRAP
 					tm.TM_GMTOFF = t->TM_GMTOFF;
 #endif
 					mkt = mktime(&tm);
 					/* If mktime fails, %s expands to the
 					   value of (time_t) -1 as a failure
 					   marker; this is better in practice
 					   than strftime failing.  */
 					if (TYPE_SIGNED(time_t)) {
 					  intmax_t n = mkt;
 					  sprintf(buf, "%"PRIdMAX, n);
 					} else {
 					  uintmax_t n = mkt;
 					  sprintf(buf, "%"PRIuMAX, n);
 					}
 					pt = _add(buf, pt, ptlim);
 				}
 				continue;
 			case 'T':
 				pt = _fmt("%H:%M:%S", t, pt, ptlim, warnp);
 				continue;
 			case 't':
 				pt = _add("\t", pt, ptlim);
 				continue;
 			case 'U':
 				pt = _conv((t->tm_yday + DAYSPERWEEK -
 					t->tm_wday) / DAYSPERWEEK,
 					"%02d", pt, ptlim);
 				continue;
 			case 'u':
 				/*
 				** From Arnold Robbins' strftime version 3.0:
 				** "ISO 8601: Weekday as a decimal number
 				** [1 (Monday) - 7]"
 				** (ado, 1993-05-24)
 				*/
 				pt = _conv((t->tm_wday == 0) ?
 					DAYSPERWEEK : t->tm_wday,
 					"%d", pt, ptlim);
 				continue;
 			case 'V':	/* ISO 8601 week number */
 			case 'G':	/* ISO 8601 year (four digits) */
 			case 'g':	/* ISO 8601 year (two digits) */
 /*
 ** From Arnold Robbins' strftime version 3.0: "the week number of the
 ** year (the first Monday as the first day of week 1) as a decimal number
 ** (01-53)."
 ** (ado, 1993-05-24)
 **
 ** From  by Markus Kuhn:
 ** "Week 01 of a year is per definition the first week which has the
 ** Thursday in this year, which is equivalent to the week which contains
 ** the fourth day of January. In other words, the first week of a new year
 ** is the week which has the majority of its days in the new year. Week 01
 ** might also contain days from the previous year and the week before week
 ** 01 of a year is the last week (52 or 53) of the previous year even if
 ** it contains days from the new year. A week starts with Monday (day 1)
 ** and ends with Sunday (day 7). For example, the first week of the year
 ** 1997 lasts from 1996-12-30 to 1997-01-05..."
 ** (ado, 1996-01-02)
 */
 				{
 					int	year;
 					int	base;
 					int	yday;
 					int	wday;
 					int	w;
 
 					year = t->tm_year;
 					base = TM_YEAR_BASE;
 					yday = t->tm_yday;
 					wday = t->tm_wday;
 					for ( ; ; ) {
 						int	len;
 						int	bot;
 						int	top;
 
 						len = isleap_sum(year, base) ?
 							DAYSPERLYEAR :
 							DAYSPERNYEAR;
 						/*
 						** What yday (-3 ... 3) does
 						** the ISO year begin on?
 						*/
 						bot = ((yday + 11 - wday) %
 							DAYSPERWEEK) - 3;
 						/*
 						** What yday does the NEXT
 						** ISO year begin on?
 						*/
 						top = bot -
 							(len % DAYSPERWEEK);
 						if (top < -3)
 							top += DAYSPERWEEK;
 						top += len;
 						if (yday >= top) {
 							++base;
 							w = 1;
 							break;
 						}
 						if (yday >= bot) {
 							w = 1 + ((yday - bot) /
 								DAYSPERWEEK);
 							break;
 						}
 						--base;
 						yday += isleap_sum(year, base) ?
 							DAYSPERLYEAR :
 							DAYSPERNYEAR;
 					}
 #ifdef XPG4_1994_04_09
 					if ((w == 52 &&
 						t->tm_mon == TM_JANUARY) ||
 						(w == 1 &&
 						t->tm_mon == TM_DECEMBER))
 							w = 53;
 #endif /* defined XPG4_1994_04_09 */
 					if (*format == 'V')
 						pt = _conv(w, "%02d",
 							pt, ptlim);
 					else if (*format == 'g') {
 						*warnp = IN_ALL;
 						pt = _yconv(year, base,
 							false, true,
 							pt, ptlim);
 					} else	pt = _yconv(year, base,
 							true, true,
 							pt, ptlim);
 				}
 				continue;
 			case 'v':
 				/*
 				** From Arnold Robbins' strftime version 3.0:
 				** "date as dd-bbb-YYYY"
 				** (ado, 1993-05-24)
 				*/
 				pt = _fmt("%e-%b-%Y", t, pt, ptlim, warnp);
 				continue;
 			case 'W':
 				pt = _conv((t->tm_yday + DAYSPERWEEK -
 					(t->tm_wday ?
 					(t->tm_wday - 1) :
 					(DAYSPERWEEK - 1))) / DAYSPERWEEK,
 					"%02d", pt, ptlim);
 				continue;
 			case 'w':
 				pt = _conv(t->tm_wday, "%d", pt, ptlim);
 				continue;
 			case 'X':
 				pt = _fmt(Locale->X_fmt, t, pt, ptlim, warnp);
 				continue;
 			case 'x':
 				{
 				enum warn warn2 = IN_SOME;
 
 				pt = _fmt(Locale->x_fmt, t, pt, ptlim, &warn2);
 				if (warn2 == IN_ALL)
 					warn2 = IN_THIS;
 				if (warn2 > *warnp)
 					*warnp = warn2;
 				}
 				continue;
 			case 'y':
 				*warnp = IN_ALL;
 				pt = _yconv(t->tm_year, TM_YEAR_BASE,
 					false, true,
 					pt, ptlim);
 				continue;
 			case 'Y':
 				pt = _yconv(t->tm_year, TM_YEAR_BASE,
 					true, true,
 					pt, ptlim);
 				continue;
 			case 'Z':
 #ifdef TM_ZONE
 				pt = _add(t->TM_ZONE, pt, ptlim);
 #elif HAVE_TZNAME
 				if (t->tm_isdst >= 0)
 					pt = _add(tzname[t->tm_isdst != 0],
 						pt, ptlim);
 #endif
 				/*
 				** C99 and later say that %Z must be
 				** replaced by the empty string if the
 				** time zone abbreviation is not
 				** determinable.
 				*/
 				continue;
 			case 'z':
 #if defined TM_GMTOFF || USG_COMPAT || ALTZONE
 				{
 				long		diff;
 				char const *	sign;
 				bool negative;
 
 # ifdef TM_GMTOFF
 				diff = t->TM_GMTOFF;
 # else
 				/*
 				** C99 and later say that the UT offset must
 				** be computed by looking only at
 				** tm_isdst. This requirement is
 				** incorrect, since it means the code
 				** must rely on magic (in this case
 				** altzone and timezone), and the
 				** magic might not have the correct
 				** offset. Doing things correctly is
 				** tricky and requires disobeying the standard;
 				** see GNU C strftime for details.
 				** For now, punt and conform to the
 				** standard, even though it's incorrect.
 				**
 				** C99 and later say that %z must be replaced by
 				** the empty string if the time zone is not
 				** determinable, so output nothing if the
 				** appropriate variables are not available.
 				*/
 				if (t->tm_isdst < 0)
 					continue;
 				if (t->tm_isdst == 0)
 #  if USG_COMPAT
 					diff = -timezone;
 #  else
 					continue;
 #  endif
 				else
 #  if ALTZONE
 					diff = -altzone;
 #  else
 					continue;
 #  endif
 # endif
 				negative = diff < 0;
 				if (diff == 0) {
 # ifdef TM_ZONE
 				  negative = t->TM_ZONE[0] == '-';
 # else
 				  negative = t->tm_isdst < 0;
 #  if HAVE_TZNAME
 				  if (tzname[t->tm_isdst != 0][0] == '-')
 				    negative = true;
 #  endif
 # endif
 				}
 				if (negative) {
 					sign = "-";
 					diff = -diff;
 				} else	sign = "+";
 				pt = _add(sign, pt, ptlim);
 				diff /= SECSPERMIN;
 				diff = (diff / MINSPERHOUR) * 100 +
 					(diff % MINSPERHOUR);
 				pt = _conv(diff, "%04d", pt, ptlim);
 				}
 #endif
 				continue;
 			case '+':
 				pt = _fmt(Locale->date_fmt, t, pt, ptlim,
 					warnp);
 				continue;
 			case '%':
 			/*
 			** X311J/88-090 (4.12.3.5): if conversion char is
 			** undefined, behavior is undefined. Print out the
 			** character itself as printf(3) also does.
 			*/
 			default:
 				break;
 			}
 		}
 		if (pt == ptlim)
 			break;
 		*pt++ = *format;
 	}
 	return pt;
 }
 
 static char *
 _conv(int n, const char *format, char *pt, const char *ptlim)
 {
 	char	buf[INT_STRLEN_MAXIMUM(int) + 1];
 
 	sprintf(buf, format, n);
 	return _add(buf, pt, ptlim);
 }
 
 static char *
 _add(const char *str, char *pt, const char *ptlim)
 {
 	while (pt < ptlim && (*pt = *str++) != '\0')
 		++pt;
 	return pt;
 }
 
 /*
 ** POSIX and the C Standard are unclear or inconsistent about
 ** what %C and %y do if the year is negative or exceeds 9999.
 ** Use the convention that %C concatenated with %y yields the
 ** same output as %Y, and that %Y contains at least 4 bytes,
 ** with more only if necessary.
 */
 
 static char *
 _yconv(int a, int b, bool convert_top, bool convert_yy,
        char *pt, const char *ptlim)
 {
 	register int	lead;
 	register int	trail;
 
 	int DIVISOR = 100;
 	trail = a % DIVISOR + b % DIVISOR;
 	lead = a / DIVISOR + b / DIVISOR + trail / DIVISOR;
 	trail %= DIVISOR;
 	if (trail < 0 && lead > 0) {
 		trail += DIVISOR;
 		--lead;
 	} else if (lead < 0 && trail > 0) {
 		trail -= DIVISOR;
 		++lead;
 	}
 	if (convert_top) {
 		if (lead == 0 && trail < 0)
 			pt = _add("-0", pt, ptlim);
 		else	pt = _conv(lead, "%02d", pt, ptlim);
 	}
 	if (convert_yy)
 		pt = _conv(((trail < 0) ? -trail : trail), "%02d", pt, ptlim);
 	return pt;
 }
diff --git a/contrib/tzcode/theory.html b/contrib/tzcode/theory.html
index 75e347f0f9d1..369c75433ff2 100644
--- a/contrib/tzcode/theory.html
+++ b/contrib/tzcode/theory.html
@@ -1,1479 +1,1501 @@
 
 
 
   Theory and pragmatics of the tz code and data
   
   
 
 
 
 
Theory and pragmatics of the tz code and data

   
Outline

   
 
 

   
Scope of the tz database

 

 The tz
 database attempts to record the history and predicted future of
 civil time scales.
 It organizes time zone and daylight saving time
 data by partitioning the world into timezones
 whose clocks all agree about timestamps that occur after the POSIX Epoch
 (1970-01-01 00:00:00 UTC).
 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.
 Most timezones correspond to a notable location and the database
 records all known clock transitions for that location;
 some timezones correspond instead to a fixed UTC offset.
 

 
 

 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
 America/Denver which observes US-style daylight saving
 time (DST),
 and America/Phoenix 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
 America/Boise, America/Edmonton, and
 America/Hermosillo, each of which currently uses mountain
 time but differs from other timezones for some timestamps after 1970.
 

 
 

 Clock transitions before 1970 are recorded for location-based timezones,
 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 backzone that is distributed along
 with the database proper, this file is less reliable and does not
 necessarily follow database guidelines.
 

 
 

 As described below, reference source code for using the
 tz database is also available.
 The tz code is upwards compatible with POSIX, an international
 standard for UNIX-like systems.
 As of this writing, the current edition of POSIX is:  The Open
 Group Base Specifications Issue 7, 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 tz 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.
 It does not always make sense to talk about a timezone's
 "base offset", which is not necessarily a single number.
 

 
 

 
 

   
Timezone identifiers

 

 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
 "Czech Republic" instead of the timezone name "Europe/Prague".
 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
 tzselect program in the tz code.
 The Unicode Common Locale Data
 Repository contains data that may be useful for other selection
 interfaces; it maps timezone names like Europe/Prague to
 locale-dependent strings like "Prague", "Praha", "Прага", and "布拉格".
 

 
 

 The naming conventions attempt to strike a balance
 among the following goals:
 

 
 
    
   
  • 
     Uniquely identify every timezone where clocks have agreed since 1970.
     This is essential for the intended use: static clocks keeping local
     civil time.
   
    • 
   
  • 
     Indicate to experts where the timezone's clocks typically are.
   
    • 
   
  • 
     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→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.
   
    • 
   
  • 
     Be portable to a wide variety of implementations.
   
    • 
   
  • 
     Use a consistent naming conventions over the entire world.
   
    • 
 

 
 

 Names normally have the form
 AREA/LOCATION, where
 AREA is a continent or ocean, and
 LOCATION is a specific location within the area.
 North and South America share the same area, 'America'.
 Typical names are 'Africa/Cairo',
 'America/New_York', and 'Pacific/Honolulu'.
 Some names are further qualified to help avoid confusion; for example,
 'America/Indiana/Petersburg' distinguishes Petersburg,
 Indiana from other Petersburgs in America.
 

 
 

 Here are the general guidelines used for
 choosing timezone names,
 in decreasing order of importance:
 

 
 
    
   
  • 
     Use only valid POSIX file name components (i.e., the parts of
     names other than '/').
     Do not use the file name components '.' and
     '..'.
     Within a file name component, use only ASCII letters,
     '.', '-' and '_'.
     Do not use digits, as that might create an ambiguity with POSIX
     TZ strings.
     A file name component must not exceed 14 characters or start with
     '-'.
     E.g., prefer America/Noronha to
     America/Fernando_de_Noronha.
     Exceptions: see the discussion of legacy names below.
   
    • 
   
  • 
     A name must not be empty, or contain '//', or
     start or end with '/'.
   
    • 
   
  • 
     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.
   
    • 
   
  • 
     If one name A is an initial prefix of another
     name AB (ignoring case), then B must not
     start with '/', as a regular file cannot have the
     same name as a directory in POSIX.
     For example, America/New_York precludes
     America/New_York/Bronx.
   
    • 
   
  • 
     Uninhabited regions like the North Pole and Bouvet Island
     do not need locations, since local time is not defined there.
   
    • 
   
  • 
     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.
   
    • 
   
  • 
     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.
   
    • 
   
  • 
     If a name is ambiguous, use a less ambiguous alternative;
     e.g., many cities are named San José and Georgetown, so
     prefer America/Costa_Rica to
     America/San_Jose and America/Guyana
     to America/Georgetown.
   
    • 
   
  • 
     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 Europe/Paris to Europe/France,
     since
     France
     has had multiple time zones.
   
    • 
   
  • 
     Use mainstream English spelling, e.g., prefer
     Europe/Rome to Europa/Roma, and
     prefer Europe/Athens to the Greek
     Ευρώπη/Αθήνα or the Romanized
     Evrópi/Athína.
     The POSIX file name restrictions encourage this guideline.
   
    • 
   
  • 
     Use the most populous among locations in a region,
     e.g., prefer Asia/Shanghai to
     Asia/Beijing.
     Among locations with similar populations, pick the best-known
     location, e.g., prefer Europe/Rome to
     Europe/Milan.
   
    • 
   
  • 
     Use the singular form, e.g., prefer Atlantic/Canary to
     Atlantic/Canaries.
   
    • 
   
  • 
     Omit common suffixes like '_Islands' and
     '_City', unless that would lead to ambiguity.
     E.g., prefer America/Cayman to
     America/Cayman_Islands and
     America/Guatemala to
     America/Guatemala_City, but prefer
     America/Mexico_City to
     America/Mexico
     because the
     country of Mexico has several time zones.
   
    • 
   
  • 
     Use '_' to represent a space.
   
    • 
   
  • 
     Omit '.' from abbreviations in names.
     E.g., prefer Atlantic/St_Helena to
     Atlantic/St._Helena.
   
    • 
   
  • 
     Do not change established names if they only marginally violate
     the above guidelines.
     For example, do not change the existing name Europe/Rome to
     Europe/Milan merely because Milan's population has grown
     to be somewhat greater than Rome's.
   
    • 
   
  • 
     If a name is changed, put its old spelling in the
     'backward' file as a link to the new spelling.
     This means old spellings will continue to work.
     Ordinarily a name change should occur only in the rare case when
     a location's consensus English-language spelling changes; for example,
     in 2008 Asia/Calcutta was renamed to Asia/Kolkata
     due to long-time widespread use of the new city name instead of the old.
   
    • 
 

 
 

 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:
 

 
 
    
 
  • 
 Older versions of this package used a different naming scheme.
 See the file 'backward' for most of these older names
 (e.g., 'US/Eastern' instead of 'America/New_York').
 The other old-fashioned names still supported are
 'WET', 'CET', 'MET', and
 'EET' (see the file 'europe').
 
    • 
 
 
  • 
 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
 'etcetera'.
 Also, the file 'backward' defines the legacy names
 'Etc/GMT0', 'Etc/GMT-0', 'Etc/GMT+0',
 'GMT0', 'GMT-0' and 'GMT+0',
 and the file 'northamerica' defines the legacy names
 'EST5EDT', 'CST6CDT',
 'MST7MDT', and 'PST8PDT'.
 
    • 
 
 
  • 
 Older versions of these guidelines said that
 there should typically be at least one name for each ISO
 3166-1 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.
 
    • 
 

 
 

 The file zone1970.tab 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 zone1970.tab location's
 longitude
 corresponds to
 its local mean
 time (LMT) offset with one hour for every 15°
 east longitude, this relationship is not exact.
 The backward-compatibility file zone.tab is similar
 but conforms to the older-version guidelines related to ISO 3166-1;
 it lists only one country code per entry and unlike zone1970.tab
 it can list names defined in backward.
 

 
 

 The database defines each timezone name to be a zone, or a link to a zone.
 The source file backward defines links for backward
 compatibility; it does not define zones.
 Although backward was originally designed to be optional,
 nowadays distributions typically use it
 and no great weight should be attached to whether a link
 is defined in backward or in some other file.
 The source file etcetera defines names that may be useful
 on platforms that do not support POSIX-style TZ strings;
 no other source file other than backward
 contains links to its zones.
 One of etcetera's names is Etc/UTC,
 used by functions like gmtime to obtain leap
 second information on platforms that support leap seconds.
 Another etcetera name, GMT,
 is used by older code releases.
 

 

 
 

   
Time zone abbreviations

 

 When this package is installed, it generates time zone abbreviations
 like 'EST' to be compatible with human tradition and POSIX.
 Here are the general guidelines used for choosing time zone abbreviations,
 in decreasing order of importance:
 

 
 
    
   
  • 
     Use three to six characters that are ASCII alphanumerics or
     '+' or '-'.
     Previous editions of this database also used characters like
     space and '?', but these characters have a
     special meaning to the
     UNIX shell
     and cause commands like
     'set
     `date`'
     to have unexpected effects.
     Previous editions of this guideline required upper-case letters, but the
     Congressman who introduced
     Chamorro
     Standard Time preferred "ChST", so lower-case letters are now
     allowed.
     Also, POSIX from 2001 on relaxed the rule to allow '-',
     '+', and alphanumeric characters from the portable
     character set in the current locale.
     In practice ASCII alphanumerics and '+' and
     '-' are safe in all locales.
 
     
    
     In other words, in the C locale the POSIX extended regular
     expression [-+[:alnum:]]{3,6} should match the
     abbreviation.
     This guarantees that all abbreviations could have been specified by a
     POSIX TZ string.
     
    
   
    • 
   
  • 
     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'.
 
     
    
     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/CWT/CPT Central [North America],
       CST/CDT China,
       GMT/BST/IST/BDST Greenwich,
       EAT East Africa,
-      EST/EDT/EWT/EPT/EDDT Eastern [North America],
+      EST/EDT/EWT/EPT Eastern [North America],
       EET/EEST Eastern European,
       GST/GDT Guam,
       HST/HDT/HWT/HPT Hawaii,
       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,
+      MST/MDT/MWT/MPT Mountain,
       NST/NDT/NWT/NPT/NDDT Newfoundland,
       NST/NDT/NWT/NPT Nome,
       NZMT/NZST New Zealand through 1945,
       NZST/NZDT New Zealand 1946–present,
       PKT/PKST Pakistan,
-      PST/PDT/PWT/PPT/PDDT Pacific,
+      PST/PDT/PWT/PPT Pacific,
       PST/PDT Philippine,
       SAST South Africa,
       SST Samoa,
       UTC Universal,
       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.
     
    
   
    • 
   
  • 
     
    
     For times taken from a city's longitude, use the
     traditional xMT notation.
     The only abbreviation like this in current use is 'GMT'.
     The others are for timestamps before 1960,
     except that Monrovia Mean Time persisted until 1972.
     Typically, numeric abbreviations (e.g., '-004430' for
     MMT) would cause trouble here, as the numeric strings would exceed
     the POSIX length limit.
     
    
 
     
    
     These abbreviations are:
       AMT Asunción, Athens;
-      BMT Baghdad, Bangkok, Batavia, Bermuda, Bern, Bogotá, Bridgetown,
+      BMT Baghdad, Bangkok, Batavia, Bermuda, Bern, Bogotá,
         Brussels, Bucharest;
       CMT Calamarca, Caracas, Chisinau, Colón, 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, Kyiv, Kingston;
-      LMT Lima, Lisbon, local, Luanda;
+      LMT Lima, Lisbon, local;
       MMT Macassar, Madras, Malé, Managua, Minsk, Monrovia, Montevideo,
 	Moratuwa, Moscow;
       PLMT Phù Liễn;
       PMT Paramaribo, Paris, Perm, Pontianak, Prague;
       PMMT Port Moresby;
+      PPMT Port-au-Prince;
       QMT Quito;
       RMT Rangoon, Riga, Rome;
       SDMT Santo Domingo;
       SJMT San José;
       SMT Santiago, Simferopol, Singapore, Stanley;
       TBMT Tbilisi;
       TMT Tallinn, Tehran;
-      WMT Warsaw;
-      ZMT Zomba.
+      WMT Warsaw.
     
    
 
     
    
     A few abbreviations also follow the pattern that
     GMT/BST established for time in the UK.
     They are:
       BMT/BST for Bermuda 1890–1930,
       CMT/BST for Calamarca Mean Time and Bolivian Summer Time
 	1890–1932,
       DMT/IST for Dublin/Dunsink Mean Time and Irish Summer Time
 	1880–1916,
       MMT/MST/MDST for Moscow 1880–1919, and
       RMT/LST for Riga Mean Time and Latvian Summer time 1880–1926.
     
     
    
   
    • 
   
  • 
     Use 'LMT' for local mean time of locations before the
     introduction of standard time; see "Scope of the
     tz database".
   
    • 
   
  • 
     If there is no common English abbreviation, use numeric offsets like
     -05 and +0530 that are generated
     by zic's %z notation.
   
    • 
   
  • 
     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.
   
    • 
   
  • 
     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.
   
    • 
   
  • 
     Use
     Universal Time
     (UT) (with time zone abbreviation '-00') for
     locations while uninhabited.
     The leading '-' is a flag that the UT offset is in
     some sense undefined; this notation is derived
     from Internet
     RFC 3339.
   
    • 
 

 
 

 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 UT offsets like
 '-0600' instead of time zone abbreviations like 'CST'.
 

 

 
 

   
Accuracy of the tz database

 

 The tz database is not authoritative, and it
 surely has errors.
 Corrections are welcome and encouraged; see the file CONTRIBUTING.
 Users requiring authoritative data should consult national standards
 bodies and the references cited in the database's comments.
 

 
 

 Errors in the tz database arise from many sources:
 

 
 
    
   
  • 
     The tz 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.
   
    • 
   
  • 
     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 tz 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
     The
     Global Transformation of Time, 1870–1950,
     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, Booked:
       A Global History of Time. Dissent 2015-12-17.
   
    • 
   
  • 
     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.
   
    • 
   
  • 
     For the UK the tz database relies on
     years of first-class work done by
     Joseph Myers and others; see
     "History of
     legal time in Britain".
     Other countries are not done nearly as well.
   
    • 
   
  • 
     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 UT offset in France
     was legally UT +00:09:21 outside train stations and
     UT +00:04:21 inside. Other examples include
     Chillicothe in 1920, Palm Springs in 1946/7, and Jerusalem and
     Ürümqi to this day.
   
    • 
   
  • 
     Although a named location in the tz
     database stands for the containing region, its pre-1970 data
     entries are often accurate for only a small subset of that region.
     For example, Europe/London 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 GMT is known to be valid only for the L&NW and
     the Caledonian railways.
   
    • 
   
  • 
     The tz 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, Europe/London is valid for all locations
     in its region after GMT was made the standard time,
     but the date of standardization (1880-08-02) is not in the
     tz database, other than in commentary.
     For many timezones the earliest time of
     validity is unknown.
   
    • 
   
  • 
     The tz database does not record a
     region's boundaries, and in many cases the boundaries are not known.
     For example, the timezone
     America/Kentucky/Louisville represents a region
     around the city of Louisville, the boundaries of which are
     unclear.
   
    • 
   
  • 
     Changes that are modeled as instantaneous transitions in the
     tz
     database were often spread out over hours, days, or even decades.
   
    • 
   
  • 
     Even if the time is specified by law, locations sometimes
     deliberately flout the law.
   
    • 
   
  • 
     Early timekeeping practices, even assuming perfect clocks, were
     often not specified to the accuracy that the
     tz database requires.
   
    • 
   
  • 
     The tz database cannot represent stopped clocks.
     However, on 1911-03-11 at 00:00, some public-facing French clocks
     were changed by stopping them for a few minutes to effect a transition.
     The tz database models this via a
     backward transition; the relevant French legislation does not
     specify exactly how the transition was to occur.
   
    • 
   
  • 
     Sometimes historical timekeeping was specified more precisely
     than what the tz code can handle.
     For example, from 1880 to 1916 clocks in Ireland observed Dublin Mean
     Time (estimated to be UT
     −00:25:21.1); although the tz
     source data can represent the .1 second, TZif files and the code cannot.
     In practice these old specifications were rarely if ever
     implemented to subsecond precision.
   
    • 
   
  • 
     Even when all the timestamp transitions recorded by the
     tz database are correct, the
     tz 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 tz database has no
     way to specify Easter, these exceptional years are entered as
     separate tz Rule lines, even though the
     legal rules did not change.
     When transitions are known but the historical rules behind them are not,
     the database contains Zone and Rule
     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.
   
    • 
   
  • 
     The tz database models time
     using the proleptic
     Gregorian calendar 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 Julian
     calendar,
     and Roman
     timekeeping 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 the
     east African practice of starting the day at dawn, renumbering
     the Western 06:00 to be 12:00. These practices are largely outside
     the scope of the tz 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 TZ setting
     like <-03>3 or America/Cayenne starts
     the day six hours later than Africa/Nairobi does.
   
    • 
   
  • 
     Early clocks were less reliable, and data entries do not represent
     clock error.
   
    • 
   
  • 
     The tz database assumes Universal Time
     (UT) as an origin, even though UT is not
     standardized for older timestamps.
     In the tz database commentary,
     UT denotes a family of time standards that includes
     Coordinated Universal Time (UTC) along with other
     variants such as UT1 and GMT,
     with days starting at midnight.
     Although UT equals UTC for modern
     timestamps, UTC was not defined until 1960, so
-    commentary uses the more-general abbreviation UT for
+    commentary uses the more general abbreviation UT for
     timestamps that might predate 1960.
     Since UT, UT1, etc. disagree slightly,
     and since pre-1972 UTC seconds varied in length,
     interpretation of older timestamps can be problematic when
     subsecond accuracy is needed.
   
    • 
   
  • 
     Civil time was not based on atomic time before 1972, and we do not
     know the history of
     earth's
     rotation accurately enough to map SI seconds to
     historical solar time
     to more than about one-hour accuracy.
     See: Stephenson FR, Morrison LV, Hohenkerk CY.
     Measurement of
     the Earth's rotation: 720 BC to AD 2015.
     Proc Royal Soc A. 2016;472:20160404.
     Also see: Espenak F. Uncertainty
     in Delta T (ΔT).
   
    • 
   
  • 
     The relationship between POSIX time (that is, UTC but
     ignoring leap
-    seconds) and UTC is not agreed upon after 1972.
+    seconds) and UTC is not agreed upon.
+    This affects time stamps during the leap second era (1972–2035).
     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.
   
    • 
   
  • 
     The tz 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.
   
    • 
 

 
 

 In short, many, perhaps most, of the tz
 database's pre-1970 and future timestamps are either wrong or
 misleading.
 Any attempt to pass the
 tz database off as the definition of time
 should be unacceptable to anybody who cares about the facts.
 In particular, the tz database's
 LMT offsets should not be considered meaningful, and
 should not prompt creation of timezones
 merely because two locations
 differ in LMT or transitioned to standard time at
 different dates.
 

 

 
 

   
Time and date functions

 

 The tz code contains time and date functions
 that are upwards compatible with those of POSIX.
 Code compatible with this package is already
 part of many platforms, 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
 'zic' supplied with this package instead of using the
 system 'zic', since the format of zic's
 input is occasionally extended, and a platform may still be shipping
 an older zic.
 

 
 
POSIX properties and limitations

 
    
   
  • 
     
    
     In POSIX, time display in a process is controlled by the
     environment variable TZ.
     Unfortunately, the POSIX
     TZ string takes a form that is hard to describe and
     is error-prone in practice.
     Also, POSIX TZ 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
+    Morocco), or with situations where more than two time zone
     abbreviations or UT offsets are used in an area.
     
    
 
     
    
     The POSIX TZ string takes the following form:
     
    
 
     
    
     stdoffset[dst[offset][,date[/time],date[/time]]]
     
    
 
     
    
     where:
     
    
 
     
    
       
    std and dst
    
 	are 3 or more characters specifying the standard
 	and daylight saving time (DST) zone abbreviations.
 	Starting with POSIX.1-2001, std and dst
 	may also be in a quoted form like '<+09>';
 	this allows "+" and "-" in the names.
       
    
       
    offset
    
 	is of the form
 	'[±]hh:[mm[:ss]]'
 	and specifies the offset west of UT.
 	'hh' may be a single digit;
 	0≤hh≤24.
 	The default DST offset is one hour ahead of
 	standard time.
       
    
       
    date[/time],date[/time]
    
 	specifies the beginning and end of DST.
 	If this is absent, the system supplies its own ruleset
-	for DST, and its rules can differ from year to year;
-	typically US DST rules are used.
+	for DST, typically	current US
+	DST rules.
       
    
       
    time
    
 	takes the form
 	'hh:[mm[:ss]]'
 	and defaults to 02:00.
 	This is the same format as the offset, except that a
 	leading '+' or '-' is not allowed.
       
    
       
    date
    
 	takes one of the following forms:
 	
    
 	  
    Jn (1≤n≤365)
    
 	    origin-1 day number not counting February 29
 	  
    
 	  
    n (0≤n≤365)
    
 	    origin-0 day number counting February 29 if present
 	  
    
 	  
    Mm.n.d
 	    (0[Sunday]≤d≤6[Saturday], 1≤n≤5,
 	    1≤m≤12)
    
 	    for the dth day of week n of
 	    month m of the year, where week 1 is the first
 	    week in which day d appears, and
 	    '5' stands for the last week in which
 	    day d appears (which may be either the 4th or
 	    5th week).
 	    Typically, this is the only useful form; the n
 	    and Jn forms are rarely used.
 	  
    
 	
    
       
    
     
    
 
     
    
     Here is an example POSIX TZ string for New
     Zealand after 2007.
     It says that standard time (NZST) is 12 hours ahead
     of UT, and that daylight saving time
     (NZDT) is observed from September's last Sunday at
     02:00 until April's first Sunday at 03:00:
     
    
 
     
    TZ='NZST-12NZDT,M9.5.0,M4.1.0/3'
    
 
     
    
     This POSIX TZ string is hard to remember, and
     mishandles some timestamps before 2008.
     With this package you can use this instead:
     
    
 
     
    TZ='Pacific/Auckland'
    
   
    • 
   
  • 
     POSIX does not define the DST transitions
     for TZ values like
     "EST5EDT".
     Traditionally the current US DST rules
     were used to interpret such values, but this meant that the
     US DST rules were compiled into each
-    program that did time conversion. This meant that when
+    time conversion package, and when
     US 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.
+    States in 1987 and again in 2007), all packages that
+    interpreted TZ values had to be updated
+    to ensure proper results.
   
    • 
   
  • 
     The TZ environment variable is process-global, which
     makes it hard to write efficient, thread-safe applications that
     need access to multiple timezones.
   
    • 
   
  • 
     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 – without regard to whether the
     user has fiddled the
     TZ environment variable.
     While an administrator can "do everything in UT" to
     get around the problem, doing so is inconvenient and precludes
     handling daylight saving time shifts – as might be required to
     limit phone calls to off-peak hours.
   
    • 
   
  • 
     POSIX provides no convenient and efficient way to determine
     the UT offset and time zone abbreviation of arbitrary
     timestamps, particularly for timezones
     that do not fit into the POSIX model.
   
    • 
   
  • 
     POSIX requires that time_t clock counts exclude leap
     seconds.
   
    • 
   
  • 
     The tz code attempts to support all the
     time_t implementations allowed by POSIX.
     The time_t type represents a nonnegative count of seconds
     since 1970-01-01 00:00:00 UTC, ignoring leap seconds.
     In practice, time_t is usually a signed 64- or 32-bit
     integer; 32-bit signed time_t values stop working after
     2038-01-19 03:14:07 UTC, 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 time_t to be a
     floating-point type, this was not supported by any practical system,
     and POSIX.1-2013 and the tz code both
     require time_t to be an integer type.
   
    • 
 

 
 
Extensions to POSIX in the
 tz code

 
    
   
  • 
     
    
     The TZ environment variable is used in generating
     the name of a file from which time-related information is read
     (or is interpreted à la POSIX); TZ is no longer
     constrained to be a string containing abbreviations
     and numeric data as described above.
     The file's format is TZif,
     a timezone information format that contains binary data; see
     Internet
     RFC 8536.
     The daylight saving time rules to be used for a
     particular timezone are encoded in the
     TZif file; the format of the file allows US,
     Australian, and other rules to be encoded, and
     allows for situations where more than two time zone
     abbreviations are used.
     
    
     
    
     It was recognized that allowing the TZ environment
     variable to take on values such as 'America/New_York'
     might cause "old" programs (that expect TZ to have a
     certain form) to operate incorrectly; consideration was given to using
     some other environment variable (for example, TIMEZONE)
     to hold the string used to generate the TZif file's name.
     In the end, however, it was decided to continue using
     TZ: it is widely used for time zone purposes;
     separately maintaining both TZ
     and TIMEZONE seemed a nuisance; and systems where
     "new" forms of TZ might cause problems can simply
     use legacy TZ values such as "EST5EDT" which
     can be used by "new" programs as well as by "old" programs that
     assume pre-POSIX TZ values.
     
    
   
    • 
   
  • 
     The code supports platforms with a UT offset member
     in struct tm, e.g., tm_gmtoff,
     or with a time zone abbreviation member in
     struct tm, e.g., tm_zone. As noted
     in Austin
     Group defect 1533, a future version of POSIX is planned to
     require tm_gmtoff and tm_zone.
   
    • 
   
  • 
     Functions tzalloc, tzfree,
     localtime_rz, and mktime_z for
     more-efficient thread-safe applications that need to use multiple
     timezones.
     The tzalloc and tzfree functions
     allocate and free objects of type timezone_t,
     and localtime_rz and mktime_z are
     like localtime_r and mktime with an
     extra timezone_t argument.
     The functions were inspired by NetBSD.
   
    • 
   
  • 
     Negative time_t values are supported, on systems
     where time_t is signed.
   
    • 
   
  • 
     These functions can account for leap seconds;
     see Leap seconds below.
   
    • 
 

 
 
POSIX features no longer needed

 

 POSIX and ISO C
 define some APIs 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 tz code supports these
 vestigial APIs for backwards compatibility, they should
 be avoided in portable applications.
 The vestigial APIs are:
 

 
    
   
  • 
     The POSIX tzname variable does not suffice and is no
     longer needed.
     To get a timestamp's time zone abbreviation, consult
     the tm_zone member if available; otherwise,
     use strftime's "%Z" conversion
     specification.
   
    • 
   
  • 
     The POSIX daylight and timezone
     variables do not suffice and are no longer needed.
     To get a timestamp's UT offset, consult
     the tm_gmtoff member if available; otherwise,
     subtract values returned by localtime
     and gmtime using the rules of the Gregorian calendar,
     or use strftime's "%z" conversion
     specification if a string like "+0900" suffices.
   
    • 
   
  • 
     The tm_isdst member is almost never needed and most of
     its uses should be discouraged in favor of the abovementioned
     APIs.
     Although it can still be used in arguments to
     mktime to disambiguate timestamps near
     a DST transition when the clock jumps back on
     platforms lacking tm_gmtoff, 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 UT offset.
   
    • 
 

 
 
Other portability notes

 
    
   
  • 
     The 7th Edition
     UNIX timezone function is not present in this
     package; it is impossible to reliably map timezone's
     arguments (a "minutes west of GMT" 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 timezone function
     may now examine localtime(&clock)->tm_zone
     (if TM_ZONE is defined) or
     tzname[localtime(&clock)->tm_isdst]
     (if HAVE_TZNAME is nonzero) to learn the correct time
     zone abbreviation to use.
   
    • 
   
  • 
     The 4.2BSD
     gettimeofday function is not
     used in this package.
     This formerly let users obtain the current UTC offset
     and DST flag, but this functionality was removed in
     later versions of BSD.
   
    • 
   
  • 
     In SVR2, time conversion fails for near-minimum or
     near-maximum time_t values when doing conversions
     for places that do not use UT.
     This package takes care to do these conversions correctly.
     A comment in the source code tells how to get compatibly wrong
     results.
   
    • 
   
  • 
     The functions that are conditionally compiled
-    if STD_INSPIRED is defined should, at this point, be
+    if STD_INSPIRED is nonzero should, at this point, be
     looked on primarily as food for thought.
     They are not in any sense "standard compatible" – some are
     not, in fact, specified in any standard.
     They do, however, represent responses of various authors to
     standardization proposals.
   
    • 
   
  • 
     Other time conversion proposals, in particular those supported by the
     Time Zone
     Database Parser, 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.
   
    • 
 

 

 
 

   
Interface stability

 

 The tz code and data supply the following interfaces:
 

 
 
    
   
  • 
     A set of timezone names as per
       "Timezone identifiers" above.
   
    • 
   
  • 
     Library functions described in "Time and date
       functions" above.
   
    • 
   
  • 
     The programs tzselect, zdump,
     and zic, documented in their man pages.
   
    • 
   
  • 
     The format of zic input files, documented in
     the zic man page.
   
    • 
   
  • 
     The format of zic output files, documented in
     the tzfile man page.
   
    • 
   
  • 
     The format of zone table files, documented in zone1970.tab.
   
    • 
   
  • 
     The format of the country code file, documented in iso3166.tab.
   
    • 
   
  • 
     The version number of the code and data, as the first line of
     the text file 'version' in each release.
   
    • 
 

 
 

 Interface changes in a release attempt to preserve compatibility with
 recent releases.
 For example, tz data files typically do not
-rely on recently-added zic features, so that users can
+rely on recently added zic features, so that users can
 run older zic versions to process newer data files.
 Downloading
 the tz database describes how releases
 are tagged and distributed.
 

 
 

 Interfaces not listed above are less stable.
 For example, users should not rely on particular UT
 offsets or abbreviations for timestamps, as data entries are often
 based on guesswork and these guesses may be corrected or improved.
 

 
 

 Timezone boundaries are not part of the stable interface.
 For example, even though the Asia/Bangkok 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 "Asia/Bangkok" in the event's record,
 the application should be robust in the presence of timezone splits
 between now and the future time.
 

 

 
 

   
Leap seconds

+

+Leap seconds were introduced in 1972 to accommodate the
+difference between atomic time and the less regular rotation of the earth.
+Unfortunately they caused so many problems with civil
+timekeeping that they
+are planned
+to be discontinued by 2035, with some as-yet-undetermined
+mechanism replacing them, perhaps after the year 2135.
+Despite their impending obsolescence, a record of leap seconds is still
+needed to resolve timestamps from 1972 through 2035.
+

+
 

 The tz 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
 Precision timekeeping,
 and this package by default installs a leapseconds file
 commonly used by
 NTP
 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
+and systems needing more precise UTC can use this package's leap
 second support directly.
 

 
 

-The directly-supported mechanism assumes that time_t
+The directly supported mechanism assumes that time_t
 counts of seconds since the POSIX epoch normally include leap seconds,
 as opposed to POSIX time_t counts which exclude leap seconds.
 This modified timescale is converted to UTC
 at the same point that time zone and DST
 adjustments are applied –
 namely, at calls to localtime and analogous functions –
 and the process is driven by leap second information
 stored in alternate versions of the TZif files.
 Because a leap second adjustment may be needed even
 if no time zone correction is desired,
 calls to gmtime-like functions
 also need to consult a TZif file,
 conventionally named Etc/UTC
 (GMT in previous versions),
 to see whether leap second corrections are needed.
 To convert an application's time_t timestamps to or from
 POSIX time_t timestamps (for use when, say,
 embedding or interpreting timestamps in portable
 tar
 files),
 the application can call the utility functions
 time2posix and posix2time
 included with this package.
 

 
 

 If the POSIX-compatible TZif file set is installed
 in a directory whose basename is zoneinfo, the
 leap-second-aware file set is by default installed in a separate
 directory zoneinfo-leaps.
 Although each process can have its own time zone by setting
 its TZ 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 zoneinfo and rename zoneinfo-leaps
 to zoneinfo.
 Alternatively, you can install just one set of TZif files
 in the first place; see the REDO variable in this package's
 makefile.
 

 

 
 

   
Calendrical issues

 

 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, Calendrical
 Calculations: The Ultimate Edition, Cambridge University Press (2018).
 Other information and sources are given in the file 'calendars'
 in the tz distribution.
 They sometimes disagree.
 

 

 
 

-  
Time and time zones on other planets

+  
Time and time zones off Earth

+

+The European Space Agency is considering
+the establishment of a reference timescale for the Moon, which has
+days roughly equivalent to 29.5 Earth days, and where relativistic
+effects cause clocks to tick slightly faster than on Earth.
+

+
 

 Some people's work schedules have used
 Mars time.
 Jet Propulsion Laboratory (JPL) coordinators kept Mars time on
 and off during the
 Mars
 Pathfinder mission (1997).
 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 (MER) mission (2004–2018).
 These timepieces looked like normal Seikos and Citizens but were adjusted
 to use Mars seconds rather than terrestrial seconds, although
 unfortunately the adjusted watches were unreliable and appear to have
 had only limited use.
 

 
 

 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.
 (One MER worker noted, "If I am working Mars hours, and Mars hours are
 2.5% more than Earth hours, shouldn't I get an extra 2.5% pay raise?")
 

 
 

 The prime
 meridian of Mars goes through the center of the crater
 Airy-0, 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 (MTC).
 

 
 

 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 MER mission 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.
 The A and B zones differ enough so that an MER worker assigned to
 the A zone might suffer "Mars lag" when switching to work in the B zone.
 Such a "time zone" is not particularly suited for any application
 other than the mission itself.
 

 
 

 Many calendars have been proposed for Mars, but none have achieved
 wide acceptance.
 Astronomers often use Mars Sol Date (MSD) which is a
 sequential count of Mars solar days elapsed since about 1873-12-29
 12:00 GMT.
 

 
 

 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
 sidereal
 rotation period 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
 retrograde:
 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.
 

 
 

 Although the tz database does not support
 time on other planets, it is documented here in the hopes that support
 will be added eventually.
 

 
 

 Sources for time on other planets:
 

 
 
 

 
 

   

   This file is in the public domain, so clarified as of 2009-05-17 by
   Arthur David Olson.
 

 
 
diff --git a/contrib/tzcode/time2posix.3 b/contrib/tzcode/time2posix.3
index 6959c890a65b..f4e4ffdc6590 100644
--- a/contrib/tzcode/time2posix.3
+++ b/contrib/tzcode/time2posix.3
@@ -1,149 +1,146 @@
 .\" This file is in the public domain, so clarified as of
 .\" 1996-06-05 by Arthur David Olson.
-.\"
-.\" $FreeBSD$
-.\"
 .Dd December 15, 2022
 .Dt TIME2POSIX 3
 .Os
 .Sh NAME
 .Nm time2posix ,
 .Nm posix2time
 .Nd convert seconds since the Epoch
 .Sh LIBRARY
 .Lb libc
 .Sh SYNOPSIS
 .In time.h
 .Ft time_t
 .Fn time2posix "time_t t"
 .Ft time_t
 .Fn posix2time "time_t t"
 .Sh DESCRIPTION
 .St -p1003.1-88
 requires the time_t value 536457599 to stand for 1986-12-31 23:59:59 UTC.
 This effectively implies that POSIX
 .Vt time_t
 values cannot include leap
 seconds and,
 therefore,
 that the system time must be adjusted as each leap occurs.
 .Pp
 If the time package is configured with leap-second support
 enabled,
 however,
 no such adjustment is needed and
 .Vt time_t
 values continue to increase over leap events
 (as a true
 .Dq "seconds since..."
 value).
 This means that these values will differ from those required by POSIX
 by the net number of leap seconds inserted since the Epoch.
 .Pp
 Typically this is not a problem as the type
 .Vt time_t
 is intended
 to be
 (mostly)
 opaque \(em
 .Vt time_t
 values should only be obtained-from and
 passed-to functions such as
 .Xr time 3 ,
 .Xr localtime 3 ,
 .Xr mktime 3
 and
 .Xr difftime 3 .
 However,
 .St -p1003.1-88
 gives an arithmetic
 expression for directly computing a
 .Vt time_t
 value from a given date/time,
 and the same relationship is assumed by some
 (usually older)
 applications.
 Any programs creating/dissecting
 .Vt time_t
 values
 using such a relationship will typically not handle intervals
 over leap seconds correctly.
 .Pp
 The
 .Fn time2posix
 and
 .Fn posix2time
 functions are provided to address this
 .Vt time_t
 mismatch by converting
 between local
 .Vt time_t
 values and their POSIX equivalents.
 This is done by accounting for the number of time-base changes that
 would have taken place on a POSIX system as leap seconds were inserted
 or deleted.
 These converted values can then be used in lieu of correcting the older
 applications,
 or when communicating with POSIX-compliant systems.
 .Pp
 The
 .Fn time2posix
 function
 is single-valued.
 That is,
 every local
 .Vt time_t
 corresponds to a single POSIX
 .Vt time_t .
 The
 .Fn posix2time
 function
 is less well-behaved:
 for a positive leap second hit the result is not unique,
 and for a negative leap second hit the corresponding
 POSIX
 .Vt time_t
 does not exist so an adjacent value is returned.
 Both of these are good indicators of the inferiority of the
 POSIX representation.
 .Pp
 The following table summarizes the relationship between a time
 T and its conversion to,
 and back from,
 the POSIX representation over the leap second inserted at the end of June,
 1993.
 .Bl -column "93/06/30" "23:59:59" "A+0" "X=time2posix(T)"
 .It Sy "DATE	TIME	T	X=time2posix(T)	posix2time(X)"
 .It "93/06/30	23:59:59	A+0	B+0	A+0"
 .It "93/06/30	23:59:60	A+1	B+1	A+1 or A+2"
 .It "93/07/01	00:00:00	A+2	B+1	A+1 or A+2"
 .It "93/07/01	00:00:01	A+3	B+2	A+3"
 .El
 .Pp
 A leap second deletion would look like...
 .Bl -column "??/06/30" "23:59:58" "A+0" "X=time2posix(T)"
 .It Sy "DATE	TIME	T	X=time2posix(T)	posix2time(X)"
 .It "??/06/30	23:59:58	A+0	B+0	A+0"
 .It "??/07/01	00:00:00	A+1	B+2	A+1"
 .It "??/07/01	00:00:01	A+2	B+3	A+2"
 .El
 .Pp
 .D1 No "[Note: posix2time(B+1) => A+0 or A+1]"
 .Pp
 If leap-second support is not enabled,
 local
 .Vt time_t
 and
 POSIX
 .Vt time_t
 values are equivalent,
 and both
 .Fn time2posix
 and
 .Fn posix2time
 degenerate to the identity function.
 .Sh "SEE ALSO"
 .Xr difftime 3 ,
 .Xr localtime 3 ,
 .Xr mktime 3 ,
 .Xr time 3
diff --git a/contrib/tzcode/tz-art.html b/contrib/tzcode/tz-art.html
index 567953415f63..c86c186c09f9 100644
--- a/contrib/tzcode/tz-art.html
+++ b/contrib/tzcode/tz-art.html
@@ -1,636 +1,649 @@
 
 
 
 
 Time and the Arts
 
 
 
Time and the Arts

 
Documentaries

 
 
Movies

 
    
 
  • 
 In the 1946 movie A Matter of Life and Death
 (U.S. title Stairway to Heaven)
 there is a reference to British Double Summer Time.
 The time does not play a large part in the plot;
 it's just a passing reference to the time when one of the
 characters was supposed to have died (but didn't).
 (IMDb entry.)
 (Dave Cantor)
 
  • 
 The 1953 railway comedy movie The Titfield Thunderbolt includes a
 play on words on British Double Summer Time. Valentine's wife wants
 him to leave the pub and asks him, "Do you know what time it is?"
 And he, happy where he is, replies: "Yes, my love. Summer double time."
 (IMDb entry.)
 (Mark Brader, 2009-10-02)
 
    • 
 
  • 
 The premise of the 1999 caper movie Entrapment involves computers
 in an international banking network being shut down briefly at
 midnight in each time zone to avoid any problems at the transition
 from the year 1999 to 2000 in that zone. (Hmmmm.) If this shutdown
 is extended by 10 seconds, it will create a one-time opportunity for
 a gigantic computerized theft. To achieve this, at one location the
 crooks interfere with the microwave system supplying time signals to
 the computer, advancing the time by 0.1 second each minute over the
 last hour of 1999. (So this movie teaches us that 0.1 × 60 = 10.)
 (IMDb entry.)
 (Mark Brader, 2009-10-02)
 
    • 
 
  • 
 One mustn't forget the
 trailer
 (2014; 2:23) for the movie Daylight Saving.
 
    • 
 

 
TV episodes

 
    
 
  • 
 An episode of The Adventures of Superman entitled "The Mysterious
 Cube," first aired 1958-02-24, had Superman convincing the controllers
 of the Arlington Time Signal to broadcast ahead of actual time;
 doing so got a crook trying to be declared dead to
 emerge a bit too early from the titular enclosure.
 (IMDb entry.)
 
    • 
 
  • 
 "The Chimes
 of Big Ben", The Prisoner, episode 2, ITC, 1967-10-06.
 Our protagonist tumbles to
 the fraudulent nature of a Poland-to-England escape upon hearing "Big
 Ben" chiming on Polish local time.
 (IMDb entry.)
 
    • 
 
  • 
 "The Susie", Seinfeld, season 8, episode 15, NBC, 1997-02-13.
 Kramer decides that daylight saving time
 isn't coming fast enough, so he sets his watch ahead an hour.
 
    • 
 
  • 
 "20 Hours in America", The West Wing, season 4, episodes 1–2,
 2002-09-25, contained a scene that
 saw White House staffers stranded in Indiana; they thought they had time to
 catch Air Force One but were done in by intra-Indiana local time changes.
 
    • 
 
  • 
 "In what time zone would you find New York City?" was a $200 question on
 the 1999-11-13 United States airing of Who Wants to Be a Millionaire?,
 and "In 1883, what industry led the movement to divide the U.S. into four time
 zones?" was a $32,000 question on the 2001-05-23 United States airing of
 the same show. At this rate, the million-dollar time-zone
 question should have been asked 2002-06-04.
 
    • 
 
  • 
 A private jet's mid-flight change of time zones distorts Alison Dubois'
 premonition in the "We Had a Dream" episode of Medium
 (originally aired 2007-02-28).
 
    • 
 
  • 
 A criminal's failure to account for the start of daylight saving is pivotal
 in "Mr. Monk
 and the Rapper" (first aired 2007-07-20).
 
    • 
 
  • 
 In the 30 Rock episode "Anna Howard Shaw Day"
 (first broadcast 2010-02-11),
 Jack Donaghy's date realizes that a Geneva-to-New-York business phone call
 received in the evening must be fake given the difference in local times.
 
    • 
 
  • 
 In the "Run by the Monkeys" episode of Da Vinci's Inquest
 (first broadcast 2002-11-17),
 a witness in a five-year-old fire case realizes they may not have set
 their clock back when daylight saving ended on the day of the fire,
 introducing the possibility of an hour when arson might have occurred.
 
    • 
 
  • 
 In "The Todd Couple" episode of Outsourced (first aired 2011-02-10),
 Manmeet sets up Valentine's Day teledates for 6:00 and 9:00pm;
 since one is with a New Yorker and the other with a San Franciscan,
 hilarity ensues.
 (Never mind that this should be 7:30am in Mumbai, yet for some reason the show
 proceeds as though it's also mid-evening there.)
 
    • 
 
  • 
 In the "14 Days to Go"/"T Minus..." episode of
 You, Me and the Apocalypse
 (first aired 2015-11-11 in the UK, 2016-03-10 in the US),
 the success of a mission to deal with a comet
 hinges on whether or not Russia observes daylight saving time.
 (In the US,
 the episode first aired in the week before the switch to DST.)
 
    • 
 
  • 
 "The Lost Hour", Eerie, Indiana, episode 10, NBC, 1991-12-01.
 Despite Indiana's then-lack of DST,
 Marshall changes his clock with unusual consequences.
 See "Eerie,
 Indiana was a few dimensions ahead of its time".
 
    • 
 
  • 
 "Time Tunnel", The Adventures of Pete & Pete, season 2, episode 5,
 Nickelodeon, 1994-10-23.
 The two Petes travel back in time an hour
 on the day that DST ends.
 
    • 
 
  • 
 "King-Size Homer", The Simpsons, episode 135, Fox, 1995-11-05.
 Homer, working from home, remarks "8:58, first
 time I've ever been early for work. Except for all those daylight
 savings days. Lousy farmers."
 
    • 
 
  • 
 Last Week Tonight with John Oliver, season 2, episode 5, 2015-03-08,
 asked, "Daylight Saving
 Time – How Is This Still A Thing?"
 
    • 
 
  • 
 "Tracks", The Good Wife, season 7, episode 12,
 CBS, 2016-01-17.
 The applicability of a contract hinges on the
 time zone associated with a video timestamp.
 
    • 
 
  • 
 "Justice", Veep, season 6, episode 4, HBO, 2017-05-07.
 Jonah's inability to understand DST ends up impressing a wealthy
 backer who sets him up for a 2020 presidential run.
 
    • 
 

 
Books, plays, and magazines

 
    
 
  • 
 Jules Verne, Around the World in Eighty Days
 (Le tour du monde en quatre-vingts jours), 1873.
 Wall-clock time plays a central role in the plot.
 European readers of the 1870s clearly held the U.S. press in
 deep contempt; the protagonists cross the U.S. without once
 reading a paper.
 Available versions include
 an English
 translation, and
 the original French
 "with illustrations from the original 1873 French-language edition".
 
    • 
 
  • 
 Nick Enright, Daylight Saving, 1989.
 A fast-paced comedy about love and loneliness as the clocks turn back.
 
    • 
 
  • 
 Umberto Eco,
 The
 Island of the Day Before
 (L'isola del giorno prima), 1994.
 "...the story of a 17th century Italian nobleman trapped near an island
 on the International Date Line.  Time and time zones play an integral
 part in the novel." (Paul Eggert, 2006-04-22)
 
    • 
 
  • 
 John Dunning, Two
 O'Clock, Eastern Wartime, 2001.
 Mystery, history, daylight saving time, and old-time radio.
 
    • 
 
  • 
 Surrealist artist Guy Billout's work "Date Line" appeared on page 103
 of the 1999-11 Atlantic Monthly.
 
    • 
 
  • 
 "Gloom, Gloom, Go Away" by Walter Kirn appeared on page 106 of Time
 magazine's 2002-11-11 issue; among other things, it proposed
 year-round DST as a way of lessening wintertime despair.
 
    • 
 

 
Music

 

 Data on recordings of "Save That Time," Russ Long, Serrob Publishing, BMI:

 

 
ArtistKarrin Allyson

 
CDI Didn't Know About You

 
Copyright Date1993

 
LabelConcord Jazz, Inc.

 
IDCCD-4543

 
Track Time3:44

 
PersonnelKarrin Allyson, vocal;
 Russ Long, piano;
 Gerald Spaits, bass;
 Todd Strait, drums

 
NotesCD notes "additional lyric by Karrin Allyson;
 arranged by Russ Long and Karrin Allyson"

 
ADO Rating1 star

 
AMG Rating4 stars

 
Penguin Rating3.5 stars

 
 

 
ArtistKevin Mahogany

 
CDDouble Rainbow

 
Copyright Date1993

 
LabelEnja Records

 
IDENJ-7097 2

 
Track Time6:27

 
PersonnelKevin Mahogany, vocal;
 Kenny Barron, piano;
 Ray Drummond, bass;
 Ralph Moore, tenor saxophone;
 Lewis Nash, drums

 
ADO Rating1.5 stars

 
AMG Rating3 stars

 
Penguin Rating3 stars

 
 

 
ArtistJoe Williams

 
CDHere's to Life

 
Copyright Date1994

 
LabelTelarc International Corporation

 
IDCD-83357

 
Track Time3:58

 
PersonnelJoe Williams, vocal
 The Robert Farnon [39 piece] Orchestra

 
NotesThis CD is also available as part of a 3-CD package from
 Telarc, "Triple Play" (CD-83461)

 
ADO Ratingblack dot

 
AMG Rating2 stars

 
Penguin Rating3 stars

 
 

 
ArtistCharles Fambrough

 
CDKeeper of the Spirit

 
Copyright Date1995

 
LabelAudioQuest Music

 
IDAQ-CD1033

 
Track Time7:07

 
PersonnelCharles Fambrough, bass;
 Joel Levine, tenor recorder;
 Edward Simon, piano;
 Lenny White, drums;
 Marion Simon, percussion

 
ADO Rating2 stars

 
AMG Ratingunrated

 
Penguin Rating3 stars

 

 

 
Also of note:

 
+
+
+
+
+
+
+
+

 
ArtistHolly Cole Trio

 
CDBlame It On My Youth

 
Copyright Date1992

 
LabelManhattan

 
IDCDP 7 97349 2

 
Total Time37:45

 
PersonnelHolly Cole, voice;
 Aaron Davis, piano;
 David Piltch, string bass

 
NotesLyrical reference to "Eastern Standard Time" in
 Tom Waits' "Purple Avenue"

 
ADO Rating2.5 stars

 
AMG Rating3 stars

 
Penguin Ratingunrated

 
 

 
ArtistMilt Hinton

 
CDOld Man Time

 
Copyright Date1990

 
LabelChiaroscuro

 
IDCR(D) 310

 
Total Time149:38 (two CDs)

 
PersonnelMilt Hinton, bass;
 Doc Cheatham, Dizzy Gillespie, Clark Terry, trumpet;
 Al Grey, trombone;
 Eddie Barefield, Joe Camel (Flip Phillips), Buddy Tate,
 clarinet and saxophone;
 John Bunch, Red Richards, Norman Simmons, Derek Smith,
 Ralph Sutton, piano;
 Danny Barker, Al Casey, guitar;
 Gus Johnson, Gerryck King, Bob Rosengarden, Jackie Williams,
 drums;
 Lionel Hampton, vibraphone;
 Cab Calloway, Joe Williams, vocal;
 Buck Clayton, arrangements

 
Notestunes include Old Man Time, Time After Time,
 Sometimes I'm Happy,
 A Hot Time in the Old Town Tonight,
 Four or Five Times, Now's the Time,
 Time on My Hands, This Time It's Us,
 and Good Time Charlie.
 Album info
 is available.

 
ADO Rating3 stars

 
AMG Rating4.5 stars

 
Penguin Rating3 stars

 
 

 
ArtistAlan Broadbent

 
CDPacific Standard Time

 
Copyright Date1995

 
LabelConcord Jazz, Inc.

 
IDCCD-4664

 
Total Time62:42

 
PersonnelAlan Broadbent, piano;
 Putter Smith, Bass;
 Frank Gibson, Jr., drums

 
NotesThe CD cover features an analemma for equation-of-time fans

 
ADO Rating1 star

 
AMG Rating4 stars

 
Penguin Rating3.5 stars

 
 

 
ArtistAnthony Braxton/Richard Teitelbaum

 
CDSilence/Time Zones

 
Copyright Date1996

 
LabelBlack Lion

 
IDBLCD 760221

 
Total Time72:58

 
PersonnelAnthony Braxton, sopranino and alto saxophones,
 contrebasse clarinet, miscellaneous instruments;
 Leo Smith, trumpet and miscellaneous instruments;
 Leroy Jenkins, violin and miscellaneous instruments;
 Richard Teitelbaum, modular moog and micromoog synthesizer

 
ADO Ratingblack dot

 
AMG Rating4 stars

 
 

 
ArtistCharles Gayle

 
CDTime Zones

 
Copyright Date2006

 
LabelTompkins Square

 
IDTSQ2839

 
Total Time49:06

 
PersonnelCharles Gayle, piano

 
ADO Rating1 star

 
AMG Rating4.5 stars

 
 

 
ArtistThe Get Up Kids

 
CDEudora

 
Copyright Date2001

 
LabelVagrant

 
ID357

 
Total Time65:12

 
NotesIncludes the song "Central Standard Time." Thanks to Colin Bowern for this information.

 
AMG Rating2.5 stars

 
 

 
 
ArtistColdplay

 
SongClocks

 
Copyright Date2003

 
LabelCapitol Records

 
ID52608

 
Total Time4:13

 
NotesWon the 2004 Record of the Year honor at the
 Grammy Awards. Co-written and performed by Chris Martin,
 great-great-grandson of DST inventor William Willett.
 The song's first line is "Lights go out and I can't be saved".

 
 

 
 
ArtistJaime Guevara

 
SongQué
 hora es

 
Date1993

 
Total Time3:04

 
NotesThe song protested "Sixto Hour" in Ecuador
 (1992–3). Its lyrics include "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").
 
 

 
 
ArtistIrving Kahal and Harry Richman

 
SongThere Ought to be a Moonlight Saving Time

 
Copyright Date1931
 
NotesThis musical standard was a No. 1 hit for Guy Lombardo
 in 1931, and was also performed by Maurice Chevalier, Blossom Dearie
 and many others. The phrase "Moonlight saving time" also appears in
 the 1995 country song "Not Enough Hours in the Night" written by Aaron
 Barker, Kim Williams and Rob Harbin and performed by Doug
 Supernaw.

 
 

 
 
ArtistThe Microscopic Septet

 
CDLobster Leaps In

 
Copyright Date2008

 
LabelCuneiform

 
ID272

 
Total Time73:05

 
NotesIncludes the song "Twilight Time Zone."

 
AMG Rating3.5 stars

 
ADO Rating2 stars

 
 
 

 
 
ArtistBob Dylan

 
CDThe Times They Are a-Changin'

 
Copyright Date1964

 
LabelColumbia

 
IDCK-8905

 
Total Time45:36

 
AMG Rating4.5 stars

 
ADO Rating1.5 stars

 
NotesThe title song is also available on "Bob Dylan's Greatest Hits" and "The Essential Bob Dylan."

 
 

 
 
ArtistLuciana Souza

 
CDTide

 
Copyright Date2009

 
LabelUniversal Jazz France

 
IDB0012688-02

 
Total Time42:31

 
AMG Rating3.5 stars

 
ADO Rating2.5 stars

 
NotesIncludes the song "Fire and Wood" with the lyric
 "The clocks were turned back you remember/Think it's still November."
 

 
 

 
ArtistKen Nordine

 
CDYou're Getting Better: The Word Jazz Dot Masters

 
Copyright Date2005

 
LabelGeffen

 
IDB0005171-02

 
Total Time156:22

 
ADO Rating1 star

 
AMG Rating4.5 stars

 
NotesIncludes the piece "What Time Is It"
 ("He knew what time it was everywhere...that counted").

 
 

 
ArtistChicago

 
CDChicago Transit Authority

 
Copyright Date1969

 
LabelColumbia

 
ID64409

 
Total Time1:16:20

 
AMG Rating4 stars

 
NotesIncludes the song "Does Anybody Really Know What Time It Is?"
 
ArtistEmanuele Arciuli
ComposerWilliam Duckworth
CDThe Time Curve Preludes
Copyright Date2023
LabelNeuma
Total Time44:46
NotesThe first work of postminimal music. Unlike minimalism, it does not assume that the listener has plenty of time.

 

 
Comics

 
 
Jokes

 
    
 
  • 
 The idea behind daylight saving time was first proposed as a joke by
 Benjamin Franklin. To enforce it, he suggested, "Every
 morning, as soon as the sun rises, let all the bells in every church
 be set ringing; and if that is not sufficient, let cannon be fired in
 every street, to wake the sluggards effectually, and make them open
 their eyes to see their true interest. All the difficulty will be in
 the first two or three days: after which the reformation will be as
 natural and easy as the present irregularity; for, ce n'est que le
 premier pas qui coûte."
 Franklin's
 joke was first published on 1784-04-26 by the
 Journal de Paris as an
 anonymous letter translated into French.
 
    • 
 
  • 
 "We've been using the five-cent nickel in this country since 1492.
 Now that's pretty near 100 years, daylight saving."
 (Groucho Marx as Captain Spaulding in Animal Crackers, 1930,
 as noted by Will Fitzgerald)
 
    • 
 
  • 
 BRADY. ...[Bishop Usher] determined that the Lord began the Creation
 on the 23rd of October in the Year 4,004 B.C. at – uh, 9 A.M.!
 
    
 DRUMMOND. That Eastern Standard Time? (Laughter.) Or Rocky Mountain
 Time? (More laughter.) It wasn't daylight-saving time, was it? Because
 the Lord didn't make the sun until the fourth day!
 
    
 (From the play Inherit the Wind by Jerome Lawrence and Robert E. Lee,
 filmed in 1960 with Spencer Tracy as Drummond and Fredric March as
 Brady, and several other times. Thanks to Mark Brader.)
 
    • 
 
  • 
 "Good news."
 "What did they do? Extend Daylight Saving Time year round?"
 (Professional tanner George Hamilton, in dialog from a
 May, 1999 episode of the syndicated television series Baywatch)
 
    • 
 
  • 
 "A fundamental belief held by Americans is that if you are on land, you
 cannot be killed by a fish...So most Americans remain on land, believing
 they're safe. Unfortunately, this belief – like so many myths, such as that
 there's a reason for 'Daylight Saving Time' – is false."
 (Dave Barry column, 2000-07-02)
 
    • 
 
  • 
 "I once had sex for an hour and five minutes, but that was on the day
 when you turn the clocks ahead."
 (Garry Shandling, 52nd Annual Emmys, 2000-09-10)
 
    • 
 
  • 
 "Would it impress you if I told you I invented Daylight Savings Time?"
 ("Sahjhan" to "Lilah" in dialog from the "Loyalty" episode of Angel,
 originally aired 2002-02-25)
 
    • 
 
  • 
 "I thought you said Tulsa was a three-hour flight."
 "Well, you're forgetting about the time difference."
 ("Joey" and "Chandler" in dialog from the episode of Friends
 entitled "The One With Rachel's Phone Number," originally aired 2002-12-05)
 
    • 
 
  • 
 "Is that a pertinent fact,
 or are you just trying to dazzle me with your command of time zones?"
 (Kelsey Grammer as "Frasier Crane" to "Roz" from the episode of Frasier
 entitled "The Kid," originally aired 1997-11-04)
 
    • 
 
  • 
 "I put myself and my staff through this crazy, huge ordeal, all because
 I refused to go on at midnight, okay?  And so I work, you know, and
 then I get this job at eleven, supposed to be a big deal.  Then
 yesterday daylight [saving] time ended. Right now it's basically
 midnight." (Conan O'Brien on the 2010-11-08 premiere of Conan.)
 
    • 
 
  • 
 "The best method, I told folks, was to hang a large clock high on a
 barn wall where all the cows could see it. If you have Holsteins, you
 will need to use an analog clock." (Jerry Nelson, How
 to adjust dairy cows to daylight saving time", Successful Farming,
 2017-10-09.)
 
    • 
 
  • 
 "And now, driving to California, I find that I must enter a password
 in order to change the time zone on my laptop clock. Evidently,
 someone is out to mess up my schedule and my clock must be secured."
 (Garrison Keillor,
 "We've
 never been here before", 2017-08-22)
 
    • 
 
  • 
 "Well, in my time zone that's all the time I have,
 but maybe in your time zone I haven't finished yet. So stay tuned!"
 (Goldie Hawn, Rowan & Martin's Laugh-In No. 65, 1970-03-09)
 
    • 
 

 
See also

 
 

 

 This web page is in the public domain, so clarified as of
 2009-05-17 by Arthur David Olson.
 

 Please send corrections to this web page to the
 time zone mailing list.
 

 
 
diff --git a/contrib/tzcode/tz-how-to.html b/contrib/tzcode/tz-how-to.html
index e1e28f2e257d..9e438f93092a 100644
--- a/contrib/tzcode/tz-how-to.html
+++ b/contrib/tzcode/tz-how-to.html
@@ -1,719 +1,719 @@
 
 
 
 How to Read the tz Database
 
 
 
 
 
How to Read the tz
 Database Source Files

 
by Bill Seymour

 
This guide uses the America/Chicago and
 Pacific/Honolulu zones as examples of how to infer
 times of day from the tz database
 source files. It might be helpful, but not absolutely necessary,
 for the reader to have already downloaded the
 latest release of the database and become familiar with the basic layout
 of the data files. The format is explained in the “man
 page” for the zic compiler, zic.8.txt, in
 the code subdirectory.
 Although this guide covers many of the common cases, it is not a
 complete summary of what zic accepts; the man page is the
 authoritative reference.

 
 
We’ll begin by talking about the rules for changing between standard
 and daylight saving time since we’ll need that information when we talk
 about the zones.

 
 
First, let’s consider the special daylight saving time rules
 for Chicago (from the northamerica file in
 the data subdirectory):

 
 

 

   From the Source File
 

 

   
     

       

 
 #Rule NAME    FROM TO    -   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
 

   

 

 

   Reformatted a Bit
 

 

   From
   To
   On
   At
   Action
 

 

   1920 only
   June 13th
   02:00 local
   go to daylight saving time
 

 

   1920
   1921
   last Sunday
   in October
   return to standard time
 

 

   1921 only
   in March
   go to daylight saving time
 

 

   1922
   1966
   in April
 

 

   1954
   in September
   return to standard time
 

 

   1955
   1966
   in October
 

 

 
 
The FROM and TO columns, respectively, specify the
 first and last calendar years defining a contiguous range over which a specific
 Rule line is to apply.  The keyword only can be used in the
 TO field to repeat the value of the FROM field in the
 event that a rule should only apply to a single year.  Often, the keyword
 max is used to extend a rule’s application into the
 indefinite future; it is a platform-agnostic stand-in for the largest
 representable year.
 
 
The next column, -, is reserved; for compatibility with earlier
 releases, it always contains a hyphen, which acts as a kind of null value.
 Prior to the 2020b release, it was called the TYPE field, though
 it had not been used in the main data since the 2000e release.
 An obsolescent supplementary file used the
 field as a proof-of-concept to allow zic to apply a given Rule
 line only to certain “types” of years within the specified range as
 dictated by the output of a separate script, such as: only years which would
 have a US presidential election, or only years which wouldn’t.
 
 
The SAVE column contains the local (wall clock) offset from
 local standard time.
 This is usually either zero for standard time or one hour for daylight
 saving time; but there’s no reason, in principle, why it can’t
 take on other values.
 
 
The LETTER (sometimes called LETTER/S)
 column can contain a variable
 part of the usual abbreviation of the time zone’s name, or it can just
 be a hyphen if there’s no variable part. For example, the abbreviation
 used in the central time zone will be either “CST” or
 “CDT”. The variable part is ‘S’ or ‘D’;
 and, sure enough, that’s just what we find in
 the LETTER column
 in the Chicago rules. More about this when we talk about
 “Zone” lines.
 
 
One important thing to notice is that “Rule” lines
 want at once to be both transitions and steady states:
 
    
 
  • On the one hand, they represent transitions between standard and
 daylight saving time; and any number of Rule lines can be in effect
 during a given period (which will always be a non-empty set of
 contiguous calendar years).
    • 
 
  • On the other hand, the SAVE and LETTER
 columns contain state that exists between transitions. More about this
 when we talk about the US rules.
    • 
 

 
 
In the example above, the transition to daylight saving time
 happened on the 13th of June in 1920, and on
 the last Sunday in March in 1921; but the return to standard time
 happened on the last Sunday in October in both of those
 years. Similarly, the rule for changing to daylight saving time was
 the same from 1922 to 1966; but the rule for returning to standard
 time changed in 1955. Got it?

 
 
OK, now for the somewhat more interesting “US” rules:

 
 

 

   From the Source File
 

 

   
     

       

 
 #Rule NAME FROM TO    -   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 23       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
 

   

 

 

   Reformatted a Bit
 

 

   From
   To
   On
   At
   Action
 

 

   1918
   1919
   last Sunday
   in March
   02:00 local
   go to daylight saving time
 

 

   in October
   return to standard time
 

 

   1942 only
   February 9th
   go to “war time”
 

 

   1945 only
   August 14th
   23:00 UT
   
     rename “war time” to “peace
time;”
     clocks don’t change
   		
 

 

   September 30th
   02:00 local
   return to standard time
 

 

   1967
   2006
   last Sunday
   in October
 

 

   1973
   in April
   go to daylight saving time
 

 

   1974 only
   January 6th
 

 

   1975 only
   February 23rd
 

 

   1976
   1986
   last Sunday
   in April
 

 

   1987
   2006
   first Sunday
 

 

   2007
   present
   second Sunday in March
 

 

   first Sunday in November
   return to standard time
 

 

 
 
There are two interesting things to note here.

 
 
First, the time that something happens (in the AT
 column) is not necessarily the local (wall clock) time. The time can be
 suffixed with ‘s’ (for “standard”) to mean
 local standard time, different from local (wall clock) time when observing
 daylight saving time; or it can be suffixed with ‘g’,
 ‘u’, or ‘z’, all three of which mean the
 standard time at the
 prime meridian.
 ‘g’ stands for “GMT”;
 ‘u’ stands for “UT” or “UTC”
 (whichever was official at the time); ‘z’ stands for the
 nautical time zone
 Z (a.k.a. “Zulu” which, in turn, stands for ‘Z’).
 The time can also be suffixed with ‘w’ meaning local (wall
 clock) time; but it usually isn’t because that’s the
 default.

 
 
Second, the day in the ON column, in addition to
 “lastSun” or a particular day of the month,
 can have the form, “Sun>=x” or
 “Sun<=x,” where x is a day
 of the month. For example, “Sun>=8” means
 “the first Sunday on or after the eighth of the month,” in
 other words, the second Sunday of the month. Furthermore, although
 there are no examples above, the weekday needn’t be
 “Sun” in either form, but can be the usual
 three-character English abbreviation for any day of the week.

 
 
And the US rules give us more examples of a couple of things
 already mentioned:

 
 
    
 
  • The rules for changing to and from daylight saving time are
 actually different sets of rules; and the two sets can change
 independently. Consider, for example, that the rule for the return to
 standard time stayed the same from 1967 to 2006; but the rule for the
 transition to daylight saving time changed several times in the same
 period.  There can also be periods, 1946 to 1966 for example, when no
 rule from this group is in effect, and so either no transition
 happened in those years, or some other rule is in effect (perhaps a
 state or other more local rule).
    • 
 
 
  • The SAVE and LETTER columns
 contain steady state, not transitions. Consider, for example,
 the transition from “war time” to “peace time”
 that happened on August 14, 1945. The “1:00” in
 the SAVE column is not an instruction to advance
 the clock an hour. It means that clocks should be one hour
 ahead of standard time, which they already are because of the previous
 rule, so there should be no change.
    • 
 
 

 
 
OK, now let’s look at a Zone record:

 
 

 

   From the Source File
 

 

   
     

       

 
 #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
 

   

 

 

   Columns Renamed
 

 

   Standard Offset

     from Prime
     Meridian		
   Daylight
Saving Time		
   Abbreviation(s)
   Ending at Local Time
 

 

   Date
   Time
 

 

   −5:50:36
   not observed
   LMT
   1883-11-18
   12:09:24
 

 

   −6:00:00
   US rules
   CST or CDT
   1920-01-01
   00:00:00
 

 

   Chicago rules
   1936-03-01
   02:00:00
 

 

   −5:00:00
   not observed
   EST
   1936-11-15
 

 

   −6:00:00
   Chicago rules
   CST or CDT
   1942-01-01
   00:00:00
 

 

   US rules
   CST, CWT or CPT
   1946-01-01
 

 

   Chicago rules
   CST or CDT
   1967-01-01
 

 

   US rules
   —
 

 

 
 
There are a couple of interesting differences between Zones and Rules.

 
 
First, and somewhat trivially, whereas Rules are considered to
 contain one or more records, a Zone is considered to be a single
 record with zero or more continuation lines. Thus, the keyword,
 “Zone,” and the zone name are not
 repeated. The last line is the one without anything in
 the [UNTIL] column.

 
 
Second, and more fundamentally, each line of a Zone represents a
 steady state, not a transition between states. The state exists from
 the date and time in the previous line’s [UNTIL]
 column up to the date and time in the current
 line’s [UNTIL] column. In other words, the date and
 time in the [UNTIL] column is the instant that separates
 this state from the next. Where that would be ambiguous because
 we’re setting our clocks back, the [UNTIL] column
 specifies the first occurrence of the instant. The state specified by
 the last line, the one without anything in the [UNTIL]
 column, continues to the present.

 
 
The first line typically specifies the mean solar time observed
 before the introduction of standard time. Since there’s no line before
 that, it has no beginning. 8-)  For some places near the International
 Date Line, the first two lines will show solar times
 differing by 24 hours; this corresponds to a movement of the Date
 Line.  For example:

 
 
 #Zone NAME          STDOFF   RULES FORMAT [UNTIL]
 Zone America/Juneau 15:02:19 -     LMT    1867 Oct 18
                     -8:57:41 -     LMT    ...
 

 
 
When Alaska was purchased from Russia in 1867, the Date Line moved
 from the Alaska/Canada border to the Bering Strait; and the time in
 Alaska was then 24 hours earlier than it had
 been. <aside>(6 October in the Julian calendar,
 which Russia was still using then for religious reasons, was followed
 by a second instance of the same day with a different name, 18
 October in the Gregorian calendar. Isn’t civil time
 wonderful? 8-))</aside>

 
 
The abbreviation, “LMT” stands for “local mean
 time”, which is an invention of
 the tz
 database and was probably never actually used during the
 period. Furthermore, the value is almost certainly wrong except in the
 archetypal place after which the zone is named. (The tz database
 usually doesn’t provide a separate Zone record for places where
 nothing significant happened after 1970.)

 
 
The RULES column tells us whether daylight saving time is being observed:
 
    
 
  • A hyphen, a kind of null value, means that we have not set our
 clocks ahead of standard time.
    • 
 
 
  • An amount of time (usually but not necessarily “1:00”
 meaning one hour) means that we have set our clocks ahead by that
 amount.
    • 
 
 
  • Some alphabetic string means that we might have set our
 clocks ahead; and we need to check the rule the name of which is the
 given alphabetic string.
    • 
 

 
 
An example of a specific amount of time is:

 
 #Zone NAME            STDOFF RULES FORMAT [UNTIL]
 Zone Pacific/Honolulu ...                 1933 Apr 30  2:00
                       -10:30 1:00  HDT    1933 May 21 12:00
                       ...
 

 
 
Hawaii tried daylight saving time for three weeks in 1933 and
 decided they didn’t like it. 8-) Note that
 the STDOFF column always contains the standard time
 offset, so the local (wall clock) time during this period was GMT −
 10:30 + 1:00 = GMT − 9:30.

 
 
The FORMAT column specifies the usual abbreviation of
 the time zone name. It should have one of four forms:

 
    
 
 
  • a time zone abbreviation that is a string of three or more
 characters that are either ASCII alphanumerics,
 “+”, or “-”
    • 
 
 
  • the string “%z”, in which case the
 “%z” will be replaced by a numeric time zone
 abbreviation
    • 
 
 
  • a pair of time zone abbreviations separated by a slash
 (‘/’), in which case the first string is the
 abbreviation for the standard time name and the second string is the
 abbreviation for the daylight saving time name
    • 
 
 
  • a string containing “%s”, in which case
 the “%s” will be replaced by the text in the
 appropriate Rule’s LETTER column, and the resulting
 string should be a time zone abbreviation
    • 
 

 
 
The last two make sense only if there’s a named rule in effect.

 
 
An example of a slash is:

 
 #Zone NAME          STDOFF RULES FORMAT  [UNTIL]
 Zone  Europe/London ...                  1996
                     0:00   EU    GMT/BST
 

 
 
The current time in the UK is called either Greenwich mean time or
 British summer time.

 
 
One wrinkle, not fully explained in zic.8.txt, is what
 happens when switching to a named rule. To what values should
 the SAVE and LETTER data be initialized?

 
 
    
 
  • If at least one transition has happened, use
 the SAVE and LETTER data from the most
 recent.
    • 
 
 
  • If switching to a named rule before any transition has happened,
 assume standard time (SAVE zero), and use
 the LETTER data from the earliest transition with
 a SAVE of zero.
 
 

 
 
And three last things about the FORMAT column:

 
    
 
 
  • The tz
-database gives abbreviations for time zones in popular
-usage, which is not necessarily “correct” by law. For
+database gives abbreviations for time zones
+in popular English-language usage. For
 example, the last line in
 Zone Pacific/Honolulu (shown below) gives
 “HST” for “Hawaii standard time” even though the
 legal
 name for that time zone is “Hawaii-Aleutian standard time.”
 This author has read that there are also some places in Australia where
 popular time zone names differ from the legal ones.
 
 
  • No attempt is made to localize
 the abbreviations. They are intended to be the values returned through the
 "%Z" format specifier to
 C’s
 strftime
 function in the
 “C” locale.
 
-
  • If there is no generally-accepted abbreviation for a time zone,
+
  • If there is no generally accepted abbreviation for a time zone,
 a numeric offset is used instead, e.g., +07 for 7 hours
 ahead of Greenwich. By convention, -00 is used in a
 zone while uninhabited, where the offset is zero but in some sense
 the true offset is undefined.
 

 
 
As a final example, here’s the complete history for Hawaii:

 
 

 

   Relevant Excerpts from the US Rules
 

 

   
     

       

 
 #Rule NAME FROM TO   -    IN  ON      AT     SAVE LETTER/S
 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 lastSun  2:00  0    S
 

   

 

 

   The Zone Record
 

 

   
     

       

 
 #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  2:00
                       -10:30    US    H%sT   1947 Jun  8  2:00
                       -10:00    -     HST
 

   

 

 

   What We Infer
 

 

   Wall-Clock
Offset from
Prime Meridian		
   Adjust
Clocks		
   Time Zone
   Ending at Local Time
 

 

   Abbrv.
   Name
   Date
   Time
 

 

   −10:31:26
   —
   LMT
   local mean time
   1896-01-13
   12:00
 

 

   −10:30
   +0:01:26
   HST
   Hawaii standard time
   1933-04-30
   02:00
 

 

   −9:30
   +1:00
   HDT
   Hawaii daylight time
   1933-05-21
   12:00
 

 

   −10:30¹
   −1:00¹
   HST¹
   Hawaii standard time
   1942-02-09
   02:00
 

 

   −9:30
   +1:00
   HWT
   Hawaii war time
   1945-08-14
   13:30²
 

 

   0
   HPT
   Hawaii peace time
   1945-09-30
   02:00
 

 

   −10:30
   −1:00
   HST
   Hawaii standard time
   1947-06-08
 

 

   −10:00³
   +0:30³
   —
 

 

   
     ¹Switching to US rules…most recent transition (in 1919) was to standard time
   
 

 

   
     ²23:00 UT
     + (−9:30) = 13:30 local
   
 

 

   
     ³Since 1947–06–08T12:30Z,
     the civil time in Hawaii has been
     UT/UTC
     − 10:00 year-round.
   
 

 

 
 
There will be a short quiz later. 8-)

 
 

 

 This web page is in the public domain, so clarified as of
 2015-10-20 by Bill Seymour.
 

 All suggestions and corrections will be welcome; all flames will be amusing.
 Mail to was at pobox dot com.
 

 
 
diff --git a/contrib/tzcode/tz-link.html b/contrib/tzcode/tz-link.html
index d3b37664c71c..43190dd7efcd 100644
--- a/contrib/tzcode/tz-link.html
+++ b/contrib/tzcode/tz-link.html
@@ -1,1175 +1,1216 @@
 
 
 
 Time zone and daylight saving time data
 
 
 
 
 
Time zone and daylight saving time data

 

 Time zone and
 daylight-saving
 rules are controlled by individual
 governments. They are sometimes changed with little notice, and their
 histories and planned futures are often recorded only fitfully. Here
 is a summary of attempts to organize and record relevant data in this
 area.
 

   
Outline

   
 
 

 
The tz database

 

 The public-domain
 time zone database contains code and data
 that represent the history of local time
 for many representative locations around the globe.
 It is updated periodically to reflect changes made by political bodies
 to time zone boundaries and daylight saving rules.
 This database (known as tz,
 tzdb, or zoneinfo)
 is used by several implementations,
 including
 the
 GNU
 C Library (used in
 GNU/Linux),
 Android,
 FreeBSD,
 NetBSD,
 OpenBSD,
 Chromium OS,
 Cygwin,
 MariaDB,
 MINIX,
 MySQL,
 webOS,
 AIX,
 iOS,
 macOS,
 Microsoft Windows,
 OpenVMS,
 Oracle Database, and
 Oracle Solaris.

 

 Each main entry in the database represents a timezone
 for a set of civil-time clocks that have all agreed since 1970.
 Timezones are typically identified by continent or ocean and then by the
 name of the largest city within the region containing the clocks.
 For example, America/New_York
 represents most of the US eastern time zone;
 America/Phoenix represents most of Arizona, which
 uses mountain time without daylight saving time (DST);
 America/Detroit represents most of Michigan, which uses
 eastern time but with different DST rules in 1975;
 and other entries represent smaller regions like Starke County,
 Indiana, which switched from central to eastern time in 1991
 and switched back in 2006.
 To use the database on an extended POSIX
 implementation set the TZ
 environment variable to the location's full name,
 e.g., TZ="America/New_York".

 

 Associated with each timezone is a history of offsets from
 Universal
 Time (UT), which is Greenwich Mean
 Time (GMT) with days beginning at midnight;
 for timestamps after 1960 this is more precisely Coordinated
 Universal Time (UTC).
 The database also records when daylight saving time was in use,
 along with some time zone abbreviations such as EST
 for Eastern Standard Time in the US.

 

 
 

 
Downloading the tz database

 

 The following shell commands download
 the latest release's two
 tarballs
 to a GNU/Linux or similar host.

 
mkdir tzdb
 cd tzdb
 wget https://www.iana.org/time-zones/repository/tzcode-latest.tar.gz
 wget https://www.iana.org/time-zones/repository/tzdata-latest.tar.gz
 gzip -dc tzcode-latest.tar.gz | tar -xf -
 gzip -dc tzdata-latest.tar.gz | tar -xf -
 

 
Alternatively, the following shell commands download the same
 release in a single-tarball format containing extra data
 useful for regression testing:

 
wget https://www.iana.org/time-zones/repository/tzdb-latest.tar.lz
 lzip -dc tzdb-latest.tar.lz | tar -xf -
 

 
These commands use convenience links to the latest release
 of the tz database hosted by the
 Time Zone Database website
 of the Internet Assigned Numbers
 Authority (IANA).
 Older releases are in files named
 tzcodeV.tar.gz,
 tzdataV.tar.gz, and
 tzdb-V.tar.lz,
 where V is the version.
 Since 1996, each version has been a four-digit year followed by
 lower-case letter (a through z,
 then za through zz, then zza
 through zzz, and so on).
 Since version 2022a, each release has been distributed in
 POSIX
 ustar interchange format, compressed as described above;
-older releases use a nearly-compatible format.
+older releases use a nearly compatible format.
 Since version 2016h, each release has contained a text file named
 "version" whose first (and currently only) line is the version.
 Older releases are archived,
 and are also available in an
 FTP directory via a
-less-secure protocol.

+less secure protocol.

 
Alternatively, a development repository of code and data can be
 retrieved from GitHub via the shell
 command:

 
git clone https://github.com/eggert/tz
 

 

 Since version 2012e, each release has been tagged in development repositories.
 Untagged commits are less well tested and probably contain
 more errors.

 

 After obtaining the code and data files, see the
 README file for what to do next.
 The code lets you compile the tz source files into
 machine-readable binary files, one for each location. The binary files
 are in a special timezone information format (TZif)
 specified by Internet
 RFC 8536.
 The code also lets
 you read a TZif file and interpret timestamps for that
 location.

 

 
 

 
Changes to the tz database

 

 The tz code and data
 are by no means authoritative. If you find errors, please
 send changes to tz@iana.org,
 the time zone mailing list. You can also subscribe to it
 and browse the archive of old
 messages.
 Metadata for mailing list
 discussions and corresponding data changes can be
 generated automatically.
 

 

-If your government plans to change its time zone boundaries or
-daylight saving rules, inform tz@iana.org well in
-advance, as this will coordinate updates to many cell phones,
-computers, and other devices around the world.
-The change should be officially announced at least a year before it affects
-how clocks operate; otherwise, there is a good chance that some
-clocks will operate incorrectly after the change, due
-to delays in propagating updates to software and data. The shorter
-the notice, the more likely clock problems will arise; see "On
-the Timing of Time Zone Changes" for examples.
-The tz data can represent planned changes
-far into the future, and a long-planned change can easily be reverted
-or otherwise altered with a year's notice before the change would have
-affected clocks.
-

-

 Changes to the tz code and data are often
 propagated to clients via operating system updates, so
 client tz data can often be corrected by
 applying these updates. With GNU/Linux and similar systems, if your
 maintenance provider has not yet adopted the
 latest tz data, you can often short-circuit
 the process by tailoring the generic instructions in
 the tz README file and installing the latest
 data yourself. System-specific instructions for installing the
 latest tz data have also been published
 for AIX,
 Android,
 ICU,
 IBM
 JDK,
 Joda-Time, MySQL,
 Noda Time, and OpenJDK/Oracle JDK.
 

 
Since version 2013a,
 sources for the tz database have been
 UTF-8
 text files
 with lines terminated by LF,
 which can be modified by common text editors such
 as GNU Emacs,
 gedit, and
 vim.
 Specialized source-file editing can be done via the
 Sublime
 zoneinfo package for Sublime Text and the VSCode
 zoneinfo extension for Visual
 Studio Code.
 

 

 For further information about updates, please see
 Procedures for
 Maintaining the Time Zone Database (Internet RFC 6557). More detail can be
 found in Theory and pragmatics of the
 tz code and data.
 A0 TimeZone Migration
 displays changes between recent tzdb versions.
 

 

 
+

+
Coordinating with governments and distributors

+

+As discussed in
+"How
+Time Zones Are Coordinated", the time zone database relies on
+collaboration among governments, the time zone database volunteer
+community, and data distributors downstream.
+

+If your government plans to change its time zone boundaries or
+daylight saving rules, please send email to tz@iana.org well in advance,
+as this will lessen confusion and will coordinate updates to many cell phones,
+computers, and other devices around the world.
+In your email, please cite the legislation or regulation that specifies
+the change, so that it can be checked for details such as the exact times
+when clock transitions occur.
+It is OK if a rule change is planned to affect clocks
+far into the future, as a long-planned change can easily be reverted
+or otherwise altered with a year's notice before the change would have
+affected clocks.

+

+There is no fixed schedule for tzdb releases.
+However, typically a release occurs every few months.
+Many downstream timezone data distributors wait for
+a tzdb release before they produce an update
+to time zone behavior in consumer devices and software products.
+After a release, various parties must integrate, test,
+and roll out an update before end users see changes.
+These updates can be expensive, for both the quality
+assurance process and the overall cost of shipping and installing
+updates to each device's copy of tzdb.
+Updates may be batched with other updates and may take substantial
+time to reach end users after a release.
+Older devices may no longer be supported and thus may never be updated,
+which means they will continue to use out-of-date rules.

+

+For these reasons any rule change should be promulgated at least a
+year before it affects how clocks operate; otherwise, there is a good
+chance that many clocks will be wrong due to delays in propagating updates,
+and that residents will be confused or even actively resist the change.
+The shorter the notice, the more likely clock problems will arise; see "On
+the Timing of Time Zone Changes" for examples.
+

+

+
 

 
Commentary on the tz database

 
 

 
 

 
Web sites using recent versions of the
 tz database

 

 These are listed roughly in ascending order of complexity and fanciness.
 

 
 

 
 

 
Network protocols for tz data

 
 

 
 

 
Other tz compilers

 
Although some of these do not fully support
 tz data, in recent tzdb
 distributions you can generally work around compatibility problems by
 running the command make rearguard_tarballs and compiling
 from the resulting tarballs instead.

 
 

 
 

 
Other TZif readers

 
    
 
  • The GNU C
 Library
 has an independent, thread-safe implementation of
 a TZif file reader.
 This library is freely available under the LGPL
 and is widely used in GNU/Linux systems.
    • 
 
  • GNOME's
 GLib has
 a TZif file reader written in C that
 creates a GTimeZone object representing sets
 of UT offsets.
 It is freely available under the LGPL.
    • 
 
  • The
 BDE Standard Library's
 baltzo::TimeZoneUtil component contains a C++
 implementation of a TZif file reader. It is freely available under
 the Apache License.
    • 
 
  • CCTZ is a simple C++
 library that translates between UT and civil time and
 can read TZif files. It is freely available under the Apache
 License.
    • 
 
  • Timelib is a C
 library that reads TZif files and converts
 timestamps from one time zone or format to another.
 It is used by PHP,
 HHVM,
 and MongoDB.
 It is freely available under the MIT license.
    • 
 
  • Tcl, mentioned above, also contains a
 TZif file reader.
    • 
 
  • 
 DateTime::TimeZone::Tzfile
 is a TZif file reader written in Perl.
 It is freely available under the same terms as Perl
 (dual GPL and Artistic license).
    • 
 
  • Python has a zoneinfo.ZoneInfo
 class that reads TZif data and creates objects
 that represent tzdb timezones.
 Python is freely available under the
 Python Software Foundation
 License.
 A companion PyPI module
 tzdata
 supplies TZif data if the underlying system data cannot be found;
 it is freely available under the Apache License.
    • 
 
  • The
 public-domain tz.js
 library contains a Python tool that
 converts TZif data into
 JSON-format data suitable for use
 in its JavaScript library for time zone conversion. Dates before 1970
 are not supported.
    • 
 
  • The timezone-olson
 package contains Haskell code that
 parses and uses TZif data. It is freely
 available under a BSD-style license.
    • 
 

 

 
 

 
Other tz-based time zone software

 
 

 
 

 
Other time zone databases

 
 

 
 

 
Maps

 
 

 
 

 
Time zone boundaries

 
Geographical boundaries between timezones are available
 from several Internet
 geolocation
 services and other sources.

 
 

 
 

 
Civil time concepts and history

 
 

 
 

 
National histories of legal time

 

 
Australia

 
The Parliamentary Library commissioned a research
 paper on daylight saving time in Australia.
 The Bureau of Meteorology publishes a list of Implementation
 Dates of Daylight Savings Time within Australia.

 
Belgium

 
The Royal Observatory of Belgium maintains a table of time in
 Belgium (in
 Dutch and French).

 
Brazil

 
The Time Service Department of the National Observatory
 records Brazil's daylight saving time decrees (in
 Portuguese).

 
Canada

 
National Research Council Canada publishes current
 and some older information about time
 zones and daylight saving time.

 
Chile

 
The Hydrographic and Oceanographic Service of the Chilean Navy publishes a
 history of
 Chile's official time (in Spanish).

 
China

 
The Hong Kong Observatory maintains a
 history of
  summer time in Hong Kong,
 and Macau's Meteorological and Geophysical Bureau maintains a similar
 history for Macau.
 Unfortunately the latter is incomplete and has errors.

 
Czech Republic

 
When daylight saving time starts and ends (in Czech)
 summarizes and cites historical DST regulations.

 
Germany

 
The National Institute for Science and Technology maintains the Realisation
 of Legal Time in Germany.

 
Israel

 
The Interior Ministry periodically issues announcements (in Hebrew).

 
Malaysia

 
See Singapore below.

 
Mexico

 
The Investigation and Analysis Service of the Mexican Library of
 Congress has published a history of Mexican local time (in Spanish).

 
Netherlands

 
Legal time in the Netherlands (in Dutch)
 covers the history of local time in the Netherlands from ancient times.

 
New Zealand

 
The Department of Internal Affairs maintains a brief History of
 Daylight Saving.

+
Palestine

+
The Ministry of Telecom and IT publishes a history of clock changes (in Arabic).

 
Portugal

 
The Lisbon Astronomical Observatory publishes a
 history of
 legal time (in Portuguese).

 
Singapore

 
Why
 is Singapore in the "Wrong" Time Zone? details the
 history of legal time in Singapore and Malaysia.

 
United Kingdom

 
History of
 legal time in Britain discusses in detail the country
 with perhaps the best-documented history of clock adjustments.

 
United States

 
The Department of Transportation's Recent
 Time Zone Proceedings lists changes to time zone boundaries.

 
Uruguay

 
The Oceanography, Hydrography, and Meteorology Service of the Uruguayan
 Navy (SOHMA) publishes an annual almanac
 (in Spanish).

 

 

 
 

 
Costs and benefits of time shifts

 
Various sources argue for and against daylight saving time and time
 zone shifts, and many scientific studies have been conducted. This
 section summarizes reviews and position statements based on
 scientific literature in the area.

 
 

 
 

 
Precision timekeeping

 
    
 
  • The
 Science of Timekeeping is a thorough introduction
 to the theory and practice of precision timekeeping.
    • 
 
  • The Science of
-Time 2016 contains several freely-readable papers.
    • 
+Time 2016 contains several freely readable papers.
 
  • NTP: The Network
 Time Protocol (Internet RFC 5905)
 discusses how to synchronize clocks of
 Internet hosts.
    • 
 
  • The Huygens
 family of software algorithms can achieve accuracy to a few tens of
 nanoseconds in scalable server farms without special hardware.
    • 
 
  • The Precision
 Time Protocol (IEEE 1588)
 can achieve submicrosecond clock accuracy on a local area network
 with special-purpose hardware.
    • 
 
  • Timezone
 Options for DHCP
 (Internet RFC 4833)
 specifies a DHCP
 option for a server to configure
 a client's time zone and daylight saving settings automatically.
    • 
 
  • Time
 Scales describes astronomical time scales like
 TDT,
 TCG, and
 TDB.
 
  • The IAU's SOFA
 collection contains C and Fortran
 code for converting among time scales like
 TAI,
 TDB, TDT and
 UTC. It is freely available under the
 SOFA license.
    • 
 
  • Mars24 Sunclock
 – Time on Mars describes Airy Mean Time (AMT) and the
 diverse local time
 scales used by each landed mission on Mars.
    • 
 
  • LeapSecond.com is
 dedicated not only to leap seconds but to precise time and frequency
 in general. It covers the state of the art in amateur timekeeping, and
 how the art has progressed over the past few decades.
    • 
 
  • 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).
    • 
 
  • IERS
 Bulletins contains official publications of the International
 Earth Rotation and Reference Systems Service, which decides when leap
 seconds occur. The tz code and data support leap seconds
 via an optional "right" configuration where a computer's internal
 time_t integer clock counts every TAI second,
 as opposed to the default "posix" configuration
 where the internal clock ignores leap seconds.
 The two configurations agree for timestamps starting with 1972-01-01 00:00:00
 UTC (time_t 63 072 000) and diverge for
 timestamps starting with time_t 78 796 800,
 which corresponds to the first leap second
 1972-06-30 23:59:60 UTC in the "right" configuration,
 and to
 1972-07-01 00:00:00 UTC in the "posix" configuration.
 In practice the two configurations also agree for timestamps before
 1972 even though the historical situation is messy, partly because
 neither UTC nor TAI
-is well-defined for sufficiently-old timestamps.
    • 
+is well-defined for sufficiently old timestamps.
 
  • Leap Smear
 discusses how to gradually adjust POSIX clocks near a
 leap second so that they disagree with UTC by at most a
 half second, even though every POSIX minute has exactly
 sixty seconds. This approach works with the default tz
 "posix" configuration, is supported by
 the NTP reference implementation, supports conversion between
 UTC and smeared POSIX timestamps, and is used by major
 cloud service providers. However, according to
 §3.7.1 of
 Network Time Protocol Best Current Practices
 (Internet RFC 8633), leap smearing is not suitable for
 applications requiring accurate UTC or civil time,
 and is intended for use only in single, well-controlled environments.
    • 
 
  • The Leap
 Second Discussion List covers McCarthy
 and Klepczynski's 1999 proposal to discontinue leap seconds,
 discussed further in
 The
 leap second: its history and possible future.
 UTC
 might be redefined
 without Leap Seconds gives pointers on this
-contentious issue, which was active until 2015 and could become active
-again.
    • 
+contentious issue.
+The General Conference on Weights and Measures
+voted in 2022
+to discontinue the use of leap seconds by 2035, replacing them with an
+as-yet-undetermined scheme some time after the year 2135.
+
 

 

 
 

 
Time notation

 
    
 
  • The Unicode Common Locale Data
 Repository (CLDR) Project has localizations for time
 zone names, abbreviations, identifiers, and formats. For example, it
 contains French translations for "Eastern European Summer Time",
 "EEST", and
 "Bucharest". Its
 by-type
 charts show these values for many locales. Data values are available in
 both LDML
 (an XML format) and JSON.
 
  • 
 A summary of
 the international standard date and time notation covers
 ISO
 8601-1:2019 – Date and time – Representations for information
 interchange – Part 1: Basic rules.
    • 
 
  • 
 XML
 Schema: Datatypes – dateTime specifies a format inspired by
 ISO 8601 that is in common use in XML data.
    • 
 
  • §3.3 of
 Internet Message Format (Internet RFC 5322)
 specifies the time notation used in email and HTTP
 headers.
    • 
 
  • 
 Date and Time
 on the Internet: Timestamps (Internet RFC 3339)
 specifies an ISO 8601
 profile for use in new Internet
 protocols.
    • 
 
  • 
 Date & Time
 Formats on the Web surveys web- and Internet-oriented date and time
 formats.
    • 
 
  • Alphabetic time zone abbreviations should not be used as unique
 identifiers for UT offsets as they are ambiguous in
 practice. For example, in English-speaking North America
 "CST" denotes 6 hours behind UT,
 but in China it denotes 8 hours ahead of UT,
 and French-speaking North Americans prefer
 "HNC" to
 "CST". The tz
 database contains English abbreviations for many timestamps;
 unfortunately some of these abbreviations were merely the database maintainers'
 inventions, and these have been removed when possible.
    • 
 
  • Numeric time zone abbreviations typically count hours east of
 UT, e.g., +09 for Japan and
 −10 for Hawaii. However, the POSIX
 TZ environment variable uses the opposite convention.
 For example, one might use TZ="JST-9" and
 TZ="HST10"
 for Japan and Hawaii, respectively. If the
 tz database is available, it is usually better to use
 settings like TZ="Asia/Tokyo" and
 TZ="Pacific/Honolulu" instead, as this should avoid
 confusion, handle old timestamps better, and insulate you better from
 any future changes to the rules. One should never set
 POSIX TZ to a value like
 "GMT-9", though, since this would incorrectly imply that
 local time is nine hours ahead of UT and the time zone
 is called "GMT".
    • 
 

 

 
 

 
See also

 
 

 
 

 

 This web page is in the public domain, so clarified as of
 2009-05-17 by Arthur David Olson.
 

 Please send corrections to this web page to the
 time zone mailing list.
 

 
 
diff --git a/contrib/tzcode/tzfile.5 b/contrib/tzcode/tzfile.5
index b53abaab18d6..d0ca730f2c96 100644
--- a/contrib/tzcode/tzfile.5
+++ b/contrib/tzcode/tzfile.5
@@ -1,492 +1,489 @@
 .\" This file is in the public domain, so clarified as of
 .\" 1996-06-05 by Arthur David Olson.
-.\"
-.\" $FreeBSD$
-.\"
 .Dd December 15, 2022
 .Dt TZFILE 5
 .Os
 .Sh NAME
 .Nm tzfile
 .Nd timezone information
 .Sh DESCRIPTION
 The timezone information files used by
 .Xr tzset 3
 are found under
 .Pa /usr/share/zoneinfo .
 These files use the format described in Internet RFC 8536.
 Each file is a sequence of 8-bit bytes.
 In a file, a binary integer is represented by a sequence of one or
 more bytes in network order (bigendian, or high-order byte first),
 with all bits significant,
 a signed binary integer is represented using two's complement,
 and a boolean is represented by a one-byte binary integer that is
 either 0 (false) or 1 (true).
 The format begins with a 44-byte header containing the following fields:
 .Pp
 .Bl -bullet
 .It
 The magic four-byte ASCII sequence
 .Dq "TZif"
 identifies the file as a timezone information file.
 .It
 A byte identifying the version of the file's format
 (as of 2021, either an ASCII NUL,
 .Dq "2" ,
 .Dq "3" ,
 or
 .Dq "4" ) .
 .It
 Fifteen bytes containing zeros reserved for future use.
 .It
 Six four-byte integer values, in the following order:
 .Pp
 .Bl -tag -compat -width tzh_ttisstdcnt
 .It Va tzh_ttisutcnt
 The number of UT/local indicators stored in the file.
 (UT is Universal Time.)
 .It Va tzh_ttisstdcnt
 The number of standard/wall indicators stored in the file.
 .It Va tzh_leapcnt
 The number of leap seconds for which data entries are stored in the file.
 .It Va tzh_timecnt
 The number of transition times for which data entries are stored
 in the file.
 .It Va tzh_typecnt
 The number of local time types for which data entries are stored
 in the file (must not be zero).
 .It Va tzh_charcnt
 The number of bytes of time zone abbreviation strings
 stored in the file.
 .El
 .El
 .Pp
 The above header is followed by the following fields, whose lengths
 depend on the contents of the header:
 .Bl -tag -compat -width tzh_timecnt
 .It Va tzh_timecnt
 four-byte signed integer values sorted in ascending order.
 These values are written in network byte order.
 Each is used as a transition time (as returned by
 .Xt time 2 )
 at which the rules for computing local time change.
 .It Va tzh_timecnt
 one-byte unsigned integer values;
 each one but the last tells which of the different types of local time types
 described in the file is associated with the time period
 starting with the same-indexed transition time
 and continuing up to but not including the next transition time.
 (The last time type is present only for consistency checking with the
 POSIX-style TZ string described below.)
 These values serve as indices into the next field.
 .It Va tzh_typecnt
 .Vt ttinfo
 entries, each defined as follows:
 .Pp
 .Bd -literal -offset indent
 struct ttinfo {
 	int32_t	tt_utoff;
 	unsigned char	tt_isdst;
 	unsigned char	tt_desigidx;
 };
 .Ed
 .Pp
 Each structure is written as a four-byte signed integer value for
 .Va tt_utoff ,
 in network byte order, followed by a one-byte boolean for
 .Va tt_isdst
 and a one-byte value for
 .Va tt_desigidx .
 In each structure,
 .Va tt_utoff
 gives the number of seconds to be added to UT,
 .Va tt_isdst
 tells whether
 .Va tm_isdst
 should be set by
 .Xr localtime 3
 and
 .Va tt_desigidx
 serves as an index into the array of time zone abbreviation bytes
 that follow the
 .Vt ttinfo
 entries in the file; if the designated string is "\*-00", the
 .Vt ttinfo
 entry is a placeholder indicating that local time is unspecified.
 The
 .Va tt_utoff
 value is never equal to \-2**31, to let 32-bit clients negate it without
 overflow.
 Also, in realistic applications
 .Va tt_utoff
 is in the range [\-89999, 93599] (i.e., more than \-25 hours and less
 than 26 hours); this allows easy support by implementations that
 already support the POSIX-required range [\-24:59:59, 25:59:59].
 .It Va tzh_charcnt
 bytes that represent time zone designations,
 which are null-terminated byte strings, each indexed by the
 .Va tt_desigidx
 values mentioned above.
 The byte strings can overlap if one is a suffix of the other.
 The encoding of these strings is not specified.
 .It Va tzh_leapcnt
 pairs of four-byte values, written in network byte order;
 the first value of each pair gives the nonnegative time
 (as returned by
 .Xr time 3 )
 at which a leap second occurs or at which the leap second table expires;
 the second is a signed integer specifying the correction, which is the
 .Em total
 number of leap seconds to be applied during the time period
 starting at the given time.
 The pairs of values are sorted in strictly ascending order by time.
 Each pair denotes one leap second, either positive or negative,
 except that if the last pair has the same correction as the previous one,
 the last pair denotes the leap second table's expiration time.
 Each leap second is at the end of a UTC calendar month.
 The first leap second has a nonnegative occurrence time,
 and is a positive leap second if and only if its correction is positive;
 the correction for each leap second after the first differs
 from the previous leap second by either 1 for a positive leap second,
 or \-1 for a negative leap second.
 If the leap second table is empty, the leap-second correction is zero
 for all timestamps;
 otherwise, for timestamps before the first occurrence time,
 the leap-second correction is zero if the first pair's correction is 1 or \-1,
 and is unspecified otherwise (which can happen only in files
 truncated at the start).
 .It Va tzh_ttisstdcnt
 standard/wall indicators, each stored as a one-byte boolean;
 they tell whether the transition times associated with local time types
 were specified as standard time or local (wall clock) time.
 .It Va tzh_ttisutcnt
 UT/local indicators, each stored as a one-byte boolean;
 they tell whether the transition times associated with local time types
 were specified as UT or local time.
 If a UT/local indicator is set, the corresponding standard/wall indicator
 must also be set.
 .El
 .Pp
 The standard/wall and UT/local indicators were designed for
 transforming a TZif file's transition times into transitions appropriate
 for another time zone specified via a POSIX-style TZ string that lacks rules.
 For example, when TZ="EET\*-2EEST" and there is no TZif file "EET\*-2EEST",
 the idea was to adapt the transition times from a TZif file with the
 well-known name "posixrules" that is present only for this purpose and
 is a copy of the file "Europe/Brussels", a file with a different UT offset.
 POSIX does not specify this obsolete transformational behavior,
 the default rules are installation-dependent, and no implementation
 is known to support this feature for timestamps past 2037,
 so users desiring (say) Greek time should instead specify
 TZ="Europe/Athens" for better historical coverage, falling back on
 TZ="EET\*-2EEST,M3.5.0/3,M10.5.0/4" if POSIX conformance is required
 and older timestamps need not be handled accurately.
 .Pp
 The
 .Xr localtime 3
 function
 normally uses the first
 .Vt ttinfo
 structure in the file
 if either
 .Va tzh_timecnt
 is zero or the time argument is less than the first transition time recorded
 in the file.
 .Ss Version 2 format
 For version-2-format timezone files,
 the above header and data are followed by a second header and data,
 identical in format except that
 eight bytes are used for each transition time or leap second time.
 (Leap second counts remain four bytes.)
 After the second header and data comes a newline-enclosed,
 POSIX-TZ-environment-variable-style string for use in handling instants
 after the last transition time stored in the file
 or for all instants if the file has no transitions.
 The POSIX-style TZ string is empty (i.e., nothing between the newlines)
 if there is no POSIX-style representation for such instants.
 If nonempty, the POSIX-style TZ string must agree with the local time
 type after the last transition time if present in the eight-byte data;
 for example, given the string
-.Dq "WET0WEST,M3.5.0,M10.5.0/3"
+.Dq "WET0WEST,M3.5.0/1,M10.5.0"
 then if a last transition time is in July, the transition's local time
 type must specify a daylight-saving time abbreviated
 .Dq "WEST"
 that is one hour east of UT.
 Also, if there is at least one transition, time type 0 is associated
 with the time period from the indefinite past up to but not including
 the earliest transition time.
 .Ss Version 3 format
 For version-3-format timezone files, the POSIX-TZ-style string may
 use two minor extensions to the POSIX TZ format, as described in
 .Xr newtzset 3 .
 First, the hours part of its transition times may be signed and range from
 \-167 through 167 instead of the POSIX-required unsigned values
 from 0 through 24.
 Second, DST is in effect all year if it starts
 January 1 at 00:00 and ends December 31 at 24:00 plus the difference
 between daylight saving and standard time.
 .Ss Version 4 format
 For version-4-format TZif files,
 the first leap second record can have a correction that is neither
 +1 nor \-1, to represent truncation of the TZif file at the start.
 Also, if two or more leap second transitions are present and the last
 entry's correction equals the previous one, the last entry
 denotes the expiration of the leap second table instead of a leap second;
 timestamps after this expiration are unreliable in that future
 releases will likely add leap second entries after the expiration, and
 the added leap seconds will change how post-expiration timestamps are treated.
 .Ss Interoperability considerations
 Future changes to the format may append more data.
 .Pp
 Version 1 files are considered a legacy format and
 should not be generated, as they do not support transition
 times after the year 2038.
 Readers that understand only Version 1 must ignore
 any data that extends beyond the calculated end of the version
 1 data block.
 .Pp
 Other than version 1, writers should generate
 the lowest version number needed by a file's data.
 For example, a writer should generate a version 4 file
 only if its leap second table either expires or is truncated at the start.
 Likewise, a writer not generating a version 4 file
 should generate a version 3 file only if
 TZ string extensions are necessary to accurately
 model transition times.
 .Pp
 The sequence of time changes defined by the version 1
 header and data block should be a contiguous sub-sequence
 of the time changes defined by the version 2+ header and data
 block, and by the footer.
 This guideline helps obsolescent version 1 readers
 agree with current readers about timestamps within the
 contiguous sub-sequence.
 It also lets writers not
 supporting obsolescent readers use a
 .Va tzh_timecnt
 of zero
 in the version 1 data block to save space.
 .Pp
 When a TZif file contains a leap second table expiration
 time, TZif readers should either refuse to process
 post-expiration timestamps, or process them as if the expiration
 time did not exist (possibly with an error indication).
 .Pp
 Time zone designations should consist of at least three (3)
 and no more than six (6) ASCII characters from the set of
 alphanumerics,
 .Dq "\*-" ,
 and
 .Dq "+" .
 This is for compatibility with POSIX requirements for
 time zone abbreviations.
 .Pp
 When reading a version 2 or higher file, readers
 should ignore the version 1 header and data block except for
 the purpose of skipping over them.
 .Pp
 Readers should calculate the total lengths of the
 headers and data blocks and check that they all fit within
 the actual file size, as part of a validity check for the file.
 .Pp
 When a positive leap second occurs, readers should append an extra
 second to the local minute containing the second just before the leap
 second.
 If this occurs when the UTC offset is not a multiple of 60
 seconds, the leap second occurs earlier than the last second of the
 local minute and the minute's remaining local seconds are numbered
 through 60 instead of the usual 59; the UTC offset is unaffected.
 .Ss Common interoperability issues
 This section documents common problems in reading or writing TZif files.
 Most of these are problems in generating TZif files for use by
 older readers.
 The goals of this section are:
 .Bl -bullet
 .It
 to help TZif writers output files that avoid common
 pitfalls in older or buggy TZif readers,
 .It
 to help TZif readers avoid common pitfalls when reading
 files generated by future TZif writers, and
 .It
 to help any future specification authors see what sort of
 problems arise when the TZif format is changed.
 .El
 .Pp
 When new versions of the TZif format have been defined, a
 design goal has been that a reader can successfully use a TZif
 file even if the file is of a later TZif version than what the
 reader was designed for.
 When complete compatibility was not achieved, an attempt was
 made to limit glitches to rarely used timestamps and allow
 simple partial workarounds in writers designed to generate
 new-version data useful even for older-version readers.
 This section attempts to document these compatibility issues and
 workarounds, as well as to document other common bugs in
 readers.
 .Pp
 Interoperability problems with TZif include the following:
 .Bl -bullet
 .It
 Some readers examine only version 1 data.
 As a partial workaround, a writer can output as much version 1
 data as possible.
 However, a reader should ignore version 1 data, and should use
 version 2+ data even if the reader's native timestamps have only
 32 bits.
 .It
 Some readers designed for version 2 might mishandle
 timestamps after a version 3 or higher file's last transition, because
 they cannot parse extensions to POSIX in the TZ-like string.
 As a partial workaround, a writer can output more transitions
 than necessary, so that only far-future timestamps are
 mishandled by version 2 readers.
 .It
 Some readers designed for version 2 do not support
 permanent daylight saving time with transitions after 24:00
 \(en e.g., a TZ string
 .Dq "EST5EDT,0/0,J365/25"
 denoting permanent Eastern Daylight Time
 (\-04).
 As a workaround, a writer can substitute standard time
 for two time zones east, e.g.,
 .Dq "XXX3EDT4,0/0,J365/23"
 for a time zone with a never-used standard time (XXX, \-03)
 and negative daylight saving time (EDT, \-04) all year.
 Alternatively,
 as a partial workaround a writer can substitute standard time
 for the next time zone east \(en e.g.,
 .Dq "AST4"
 for permanent
 Atlantic Standard Time (\-04).
 .It
 Some readers designed for version 2 or 3, and that require strict
 conformance to RFC 8536, reject version 4 files whose leap second
 tables are truncated at the start or that end in expiration times.
 .It
 Some readers ignore the footer, and instead predict future
 timestamps from the time type of the last transition.
 As a partial workaround, a writer can output more transitions
 than necessary.
 .It
 Some readers do not use time type 0 for timestamps before
 the first transition, in that they infer a time type using a
 heuristic that does not always select time type 0.
 As a partial workaround, a writer can output a dummy (no-op)
 first transition at an early time.
 .It
 Some readers mishandle timestamps before the first
 transition that has a timestamp not less than \-2**31.
 Readers that support only 32-bit timestamps are likely to be
 more prone to this problem, for example, when they process
 64-bit transitions only some of which are representable in 32
 bits.
 As a partial workaround, a writer can output a dummy
 transition at timestamp \-2**31.
 .It
 Some readers mishandle a transition if its timestamp has
 the minimum possible signed 64-bit value.
 Timestamps less than \-2**59 are not recommended.
 .It
 Some readers mishandle POSIX-style TZ strings that
 contain
 .Dq "<"
 or
 .Dq ">".
 As a partial workaround, a writer can avoid using
 .Dq "<"
 or
 .Dq ">"
 for time zone abbreviations containing only alphabetic
 characters.
 .It
 Many readers mishandle time zone abbreviations that contain
 non-ASCII characters.
 These characters are not recommended.
 .It
 Some readers may mishandle time zone abbreviations that
 contain fewer than 3 or more than 6 characters, or that
 contain ASCII characters other than alphanumerics,
 .Dq "\*-",
 and
 .Dq "+".
 These abbreviations are not recommended.
 .It
 Some readers mishandle TZif files that specify
 daylight-saving time UT offsets that are less than the UT
 offsets for the corresponding standard time.
 These readers do not support locations like Ireland, which
 uses the equivalent of the POSIX TZ string
 .Dq "IST\*-1GMT0,M10.5.0,M3.5.0/1" ,
 observing standard time
 (IST, +01) in summer and daylight saving time (GMT, +00) in winter.
 As a partial workaround, a writer can output data for the
 equivalent of the POSIX TZ string
 .Dq "GMT0IST,M3.5.0/1,M10.5.0" ,
 thus swapping standard and daylight saving time.
 Although this workaround misidentifies which part of the year
 uses daylight saving time, it records UT offsets and time zone
 abbreviations correctly.
 .It
 Some readers generate ambiguous timestamps for positive leap seconds
 that occur when the UTC offset is not a multiple of 60 seconds.
 For example, in a timezone with UTC offset +01:23:45 and with
 a positive leap second 78796801 (1972-06-30 23:59:60 UTC), some readers will
 map both 78796800 and 78796801 to 01:23:45 local time the next day
 instead of mapping the latter to 01:23:46, and they will map 78796815 to
 01:23:59 instead of to 01:23:60.
 This has not yet been a practical problem, since no civil authority
 has observed such UTC offsets since leap seconds were
 introduced in 1972.
 .El
 .Pp
 Some interoperability problems are reader bugs that
 are listed here mostly as warnings to developers of readers.
 .Bl -bullet
 .It
 Some readers do not support negative timestamps.
 Developers of distributed applications should keep this
 in mind if they need to deal with pre-1970 data.
 .It
 Some readers mishandle timestamps before the first
 transition that has a nonnegative timestamp.
 Readers that do not support negative timestamps are likely to
 be more prone to this problem.
 .It
 Some readers mishandle time zone abbreviations like
 .Dq "\*-08"
 that contain
 .Dq "+" ,
 .Dq "\*-" ,
 or digits.
 .It
 Some readers mishandle UT offsets that are out of the
 traditional range of \-12 through +12 hours, and so do not
 support locations like Kiritimati that are outside this
 range.
 .It
 Some readers mishandle UT offsets in the range [\-3599, \-1]
 seconds from UT, because they integer-divide the offset by
 3600 to get 0 and then display the hour part as
 .Dq "+00" .
 .It
 Some readers mishandle UT offsets that are not a multiple
 of one hour, or of 15 minutes, or of 1 minute.
 .El
 .Sh SEE ALSO
 .Xr time 3 ,
 .Xr localtime 3 ,
 .Xr tzset 3 ,
 .Xr tzsetup 8 ,
 .Xr zic 8 ,
 .Xr zdump 8
 .Rs
 .%A A. Olson
 .%A P. Eggert
 .%A K. Murchison
 .%T "The Time Zone Information Format (TZif)"
 .%R RFC 8536
 .%D February 2019
 .%U https://datatracker.ietf.org/doc/html/rfc8536
 .%U https://doi.org/10.17487/RFC8536
 .Re
diff --git a/contrib/tzcode/tzfile.h b/contrib/tzcode/tzfile.h
index e59d2ea4bb47..3764f36d4d92 100644
--- a/contrib/tzcode/tzfile.h
+++ b/contrib/tzcode/tzfile.h
@@ -1,125 +1,129 @@
 /* Layout and location of TZif files.  */
 
 #ifndef TZFILE_H
 #define TZFILE_H
 
 
 /*
 ** This file is in the public domain, so clarified as of
 ** 1996-06-05 by Arthur David Olson.
 **
 ** $FreeBSD$
 */
 
 /*
 ** This header is for use ONLY with the time conversion code.
 ** There is no guarantee that it will remain unchanged,
 ** or that it will remain at all.
 ** Do NOT copy it to any system include directory.
 ** Thank you!
 */
 
 /*
 ** Information about time zone files.
 */
 
 #ifndef TZDIR
 # define TZDIR "/usr/share/zoneinfo" /* Time zone object file directory */
 #endif /* !defined TZDIR */
 
 #ifndef TZDEFAULT
 # define TZDEFAULT "/etc/localtime"
 #endif /* !defined TZDEFAULT */
 
 #ifndef TZDEFRULES
 # define TZDEFRULES "posixrules"
 #endif /* !defined TZDEFRULES */
 
 
 /* See Internet RFC 8536 for more details about the following format.  */
 
 /*
 ** Each file begins with. . .
 */
 
 #define	TZ_MAGIC	"TZif"
 
 struct tzhead {
 	char	tzh_magic[4];		/* TZ_MAGIC */
 	char	tzh_version[1];		/* '\0' or '2'-'4' as of 2021 */
 	char	tzh_reserved[15];	/* reserved; must be zero */
 	char	tzh_ttisutcnt[4];	/* coded number of trans. time flags */
 	char	tzh_ttisstdcnt[4];	/* coded number of trans. time flags */
 	char	tzh_leapcnt[4];		/* coded number of leap seconds */
 	char	tzh_timecnt[4];		/* coded number of transition times */
 	char	tzh_typecnt[4];		/* coded number of local time types */
 	char	tzh_charcnt[4];		/* coded number of abbr. chars */
 };
 
 /*
 ** . . .followed by. . .
 **
 **	tzh_timecnt (char [4])s		coded transition times a la time(2)
 **	tzh_timecnt (unsigned char)s	types of local time starting at above
 **	tzh_typecnt repetitions of
 **		one (char [4])		coded UT offset in seconds
 **		one (unsigned char)	used to set tm_isdst
 **		one (unsigned char)	that's an abbreviation list index
 **	tzh_charcnt (char)s		'\0'-terminated zone abbreviations
 **	tzh_leapcnt repetitions of
 **		one (char [4])		coded leap second transition times
 **		one (char [4])		total correction after above
 **	tzh_ttisstdcnt (char)s		indexed by type; if 1, transition
 **					time is standard time, if 0,
 **					transition time is local (wall clock)
 **					time; if absent, transition times are
 **					assumed to be local time
 **	tzh_ttisutcnt (char)s		indexed by type; if 1, transition
 **					time is UT, if 0, transition time is
 **					local time; if absent, transition
 **					times are assumed to be local time.
 **					When this is 1, the corresponding
 **					std/wall indicator must also be 1.
 */
 
 /*
 ** If tzh_version is '2' or greater, the above is followed by a second instance
 ** of tzhead and a second instance of the data in which each coded transition
 ** time uses 8 rather than 4 chars,
 ** then a POSIX-TZ-environment-variable-style string for use in handling
 ** instants after the last transition time stored in the file
 ** (with nothing between the newlines if there is no POSIX representation for
 ** such instants).
 **
 ** If tz_version is '3' or greater, the above is extended as follows.
 ** First, the POSIX TZ string's hour offset may range from -167
 ** through 167 as compared to the POSIX-required 0 through 24.
 ** Second, its DST start time may be January 1 at 00:00 and its stop
 ** time December 31 at 24:00 plus the difference between DST and
 ** standard time, indicating DST all year.
 */
 
 /*
 ** In the current implementation, "tzset()" refuses to deal with files that
 ** exceed any of the limits below.
 */
 
 #ifndef TZ_MAX_TIMES
+/* This must be at least 242 for Europe/London with 'zic -b fat'.  */
 # define TZ_MAX_TIMES 2000
 #endif /* !defined TZ_MAX_TIMES */
 
 #ifndef TZ_MAX_TYPES
-/* This must be at least 17 for Europe/Samara and Europe/Vilnius.  */
+/* This must be at least 18 for Europe/Vilnius with 'zic -b fat'.  */
 # define TZ_MAX_TYPES 256 /* Limited by what (unsigned char)'s can hold */
 #endif /* !defined TZ_MAX_TYPES */
 
 #ifndef TZ_MAX_CHARS
+/* This must be at least 40 for America/Anchorage.  */
 # define TZ_MAX_CHARS 50	/* Maximum number of abbreviation characters */
 				/* (limited by what unsigned chars can hold) */
 #endif /* !defined TZ_MAX_CHARS */
 
 #ifndef TZ_MAX_LEAPS
+/* This must be at least 27 for leap seconds from 1972 through mid-2023.
+   There's a plan to discontinue leap seconds by 2035.  */
 # define TZ_MAX_LEAPS 50	/* Maximum number of leap second corrections */
 #endif /* !defined TZ_MAX_LEAPS */
 
 #endif /* !defined TZFILE_H */
diff --git a/contrib/tzcode/tzselect.8 b/contrib/tzcode/tzselect.8
index 846b867be1c0..4578090f9ea7 100644
--- a/contrib/tzcode/tzselect.8
+++ b/contrib/tzcode/tzselect.8
@@ -1,125 +1,125 @@
 .\" This file is in the public domain, so clarified as of
 .\" 2009-05-17 by Arthur David Olson.
-.TH TZSELECT 8
+.TH tzselect 8 "" "Time Zone Database"
 .SH NAME
 tzselect \- select a timezone
 .SH SYNOPSIS
 .ie \n(.g .ds - \f(CR-\fP
 .el .ds - \-
 .ds d " degrees
 .ds m " minutes
 .ds s " seconds
 .ds _ " \&
 .if t \{\
 . if \n(.g .if c \(de .if c \(fm .if c \(sd \{\
 .  ds d \(de
 .  ds m \(fm
 .  ds s \(sd
 .  ds _ \|
 . \}
 .\}
 .B tzselect
 [
 .B \*-c
 .I coord
 ] [
 .B \*-n
 .I limit
 ] [
 .B \*-\*-help
 ] [
 .B \*-\*-version
 ]
 .SH DESCRIPTION
 The
 .B tzselect
 program asks the user for information about the current location,
 and outputs the resulting timezone to standard output.
 The output is suitable as a value for the TZ environment variable.
 .PP
 All interaction with the user is done via standard input and standard error.
 .SH OPTIONS
 .TP
 .BI "\*-c " coord
 Instead of asking for continent and then country and then city,
 ask for selection from time zones whose largest cities
 are closest to the location with geographical coordinates
 .I coord.
 Use ISO 6709 notation for
 .I coord,
 that is, a latitude immediately followed by a longitude.  The latitude
 and longitude should be signed integers followed by an optional
 decimal point and fraction: positive numbers represent north and east,
 negative south and west.  Latitudes with two and longitudes with three
 integer digits are treated as degrees; latitudes with four or six and
 longitudes with five or seven integer digits are treated as
 .I "DDMM, DDDMM, DDMMSS,"
 or
 .I DDDMMSS
 representing
 .I DD
 or
 .I DDD
 degrees,
 .I MM
 minutes,
 and zero or
 .I SS
 seconds, with any trailing fractions represent fractional minutes or
 (if
 .I SS
 is present) seconds.  The decimal point is that of the current locale.
 For example, in the (default) C locale,
 .B "\*-c\ +40.689\*-074.045"
 specifies 40.689\*d\*_N, 74.045\*d\*_W,
 .B "\*-c\ +4041.4\*-07402.7"
 specifies 40\*d\*_41.4\*m\*_N, 74\*d\*_2.7\*m\*_W, and
 .B "\*-c\ +404121\*-0740240"
 specifies 40\*d\*_41\*m\*_21\*s\*_N, 74\*d\*_2\*m\*_40\*s\*_W.
 If
 .I coord
 is not one of the documented forms, the resulting behavior is unspecified.
 .TP
 .BI "\*-n " limit
 When
 .B \*-c
 is used, display the closest
 .I limit
 locations (default 10).
 .TP
 .B "\*-\*-help"
 Output help information and exit.
 .TP
 .B "\*-\*-version"
 Output version information and exit.
 .SH "ENVIRONMENT VARIABLES"
 .TP
 \f3AWK\fP
 Name of a Posix-compliant
 .B awk
 program (default:
 .BR awk ).
 .TP
 \f3TZDIR\fP
 Name of the directory containing timezone data files (default:
 .BR /usr/share/zoneinfo ).
 .SH FILES
 .TP
 \f2TZDIR\fP\f3/iso3166.tab\fP
 Table of ISO 3166 2-letter country codes and country names.
 .TP
 \f2TZDIR\fP\f3/zone1970.tab\fP
 Table of country codes, latitude and longitude, timezones, and
 descriptive comments.
 .TP
 \f2TZDIR\fP\f3/\fP\f2TZ\fP
 Timezone data file for timezone \f2TZ\fP.
 .SH "EXIT STATUS"
 The exit status is zero if a timezone was successfully obtained from the user,
 nonzero otherwise.
 .SH "SEE ALSO"
 newctime(3), tzfile(5), zdump(8), zic(8)
 .SH NOTES
 Applications should not assume that
 .BR tzselect 's
 output matches the user's political preferences.
diff --git a/contrib/tzcode/tzselect.ksh b/contrib/tzcode/tzselect.ksh
index 28c32a2430f8..9a91acfc7412 100644
--- a/contrib/tzcode/tzselect.ksh
+++ b/contrib/tzcode/tzselect.ksh
@@ -1,586 +1,693 @@
 #!/bin/bash
 # Ask the user about the time zone, and output the resulting TZ value to stdout.
 # Interact with the user via stderr and stdin.
 
 PKGVERSION='(tzcode) '
 TZVERSION=see_Makefile
 REPORT_BUGS_TO=tz@iana.org
 
 # Contributed by Paul Eggert.  This file is in the public domain.
 
 # Porting notes:
 #
 # This script requires a Posix-like shell and prefers the extension of a
 # 'select' statement.  The 'select' statement was introduced in the
 # Korn shell and is available in Bash and other shell implementations.
 # If your host lacks both Bash and the Korn shell, you can get their
 # source from one of these locations:
 #
 #	Bash 
 #	Korn Shell 
 #	MirBSD Korn Shell 
 #
 # For portability to Solaris 10 /bin/sh (supported by Oracle through
 # January 2024) this script avoids some POSIX features and common
 # extensions, such as $(...) (which works sometimes but not others),
 # $((...)), ! CMD, ${#ID}, ${ID##PAT}, ${ID%%PAT}, and $10.
 
 #
 # This script also uses several features of modern awk programs.
 # If your host lacks awk, or has an old awk that does not conform to Posix,
 # you can use either of the following free programs instead:
 #
 #	Gawk (GNU awk) 
 #	mawk 
 #	nawk 
 
 
 # Specify default values for environment variables if they are unset.
 : ${AWK=awk}
 : ${TZDIR=`pwd`}
 
-# Output one argument as-is to standard output.
+# Output one argument as-is to standard output, with trailing newline.
 # Safer than 'echo', which can mishandle '\' or leading '-'.
 say() {
     printf '%s\n' "$1"
 }
 
 # Check for awk Posix compliance.
 ($AWK -v x=y 'BEGIN { exit 123 }') /dev/null 2>&1
 [ $? = 123 ] || {
 	say >&2 "$0: Sorry, your '$AWK' program is not Posix compatible."
 	exit 1
 }
 
 coord=
 location_limit=10
 zonetabtype=zone1970
 
 usage="Usage: tzselect [--version] [--help] [-c COORD] [-n LIMIT]
 Select a timezone interactively.
 
 Options:
 
   -c COORD
     Instead of asking for continent and then country and then city,
     ask for selection from time zones whose largest cities
     are closest to the location with geographical coordinates COORD.
     COORD should use ISO 6709 notation, for example, '-c +4852+00220'
     for Paris (in degrees and minutes, North and East), or
     '-c -35-058' for Buenos Aires (in degrees, South and West).
 
   -n LIMIT
     Display at most LIMIT locations when -c is used (default $location_limit).
 
   --version
     Output version information.
 
   --help
     Output this help.
 
 Report bugs to $REPORT_BUGS_TO."
 
 # Ask the user to select from the function's arguments,
 # and assign the selected argument to the variable 'select_result'.
-# Exit on EOF or I/O error.  Use the shell's 'select' builtin if available,
-# falling back on a less-nice but portable substitute otherwise.
+# Exit on EOF or I/O error.  Use the shell's nicer 'select' builtin if
+# available, falling back on a portable substitute otherwise.
 if
   case $BASH_VERSION in
   ?*) : ;;
   '')
     # '; exit' should be redundant, but Dash doesn't properly fail without it.
     (eval 'set --; select x; do break; done; exit') /dev/null
   esac
 then
   # Do this inside 'eval', as otherwise the shell might exit when parsing it
   # even though it is never executed.
   eval '
     doselect() {
       select select_result
       do
 	case $select_result in
 	"") echo >&2 "Please enter a number in range." ;;
 	?*) break
 	esac
       done || exit
     }
   '
 else
   doselect() {
     # Field width of the prompt numbers.
     select_width=`expr $# : '.*'`
 
     select_i=
 
     while :
     do
       case $select_i in
       '')
 	select_i=0
 	for select_word
 	do
 	  select_i=`expr $select_i + 1`
 	  printf >&2 "%${select_width}d) %s\\n" $select_i "$select_word"
 	done ;;
       *[!0-9]*)
 	echo >&2 'Please enter a number in range.' ;;
       *)
 	if test 1 -le $select_i && test $select_i -le $#; then
 	  shift `expr $select_i - 1`
 	  select_result=$1
 	  break
 	fi
 	echo >&2 'Please enter a number in range.'
       esac
 
       # Prompt and read input.
       printf >&2 %s "${PS3-#? }"
       read select_i || exit
     done
   }
 fi
 
 while getopts c:n:t:-: opt
 do
     case $opt$OPTARG in
     c*)
 	coord=$OPTARG ;;
     n*)
 	location_limit=$OPTARG ;;
     t*) # Undocumented option, used for developer testing.
 	zonetabtype=$OPTARG ;;
     -help)
 	exec echo "$usage" ;;
     -version)
 	exec echo "tzselect $PKGVERSION$TZVERSION" ;;
     -*)
 	say >&2 "$0: -$opt$OPTARG: unknown option; try '$0 --help'"; exit 1 ;;
     *)
 	say >&2 "$0: try '$0 --help'"; exit 1 ;;
     esac
 done
 
 shift `expr $OPTIND - 1`
 case $# in
 0) ;;
 *) say >&2 "$0: $1: unknown argument"; exit 1 ;;
 esac
 
 # Make sure the tables are readable.
 TZ_COUNTRY_TABLE=$TZDIR/iso3166.tab
 TZ_ZONE_TABLE=$TZDIR/$zonetabtype.tab
 for f in $TZ_COUNTRY_TABLE $TZ_ZONE_TABLE
 do
 	<"$f" || {
 		say >&2 "$0: time zone files are not set up correctly"
 		exit 1
 	}
 done
 
 # If the current locale does not support UTF-8, convert data to current
 # locale's format if possible, as the shell aligns columns better that way.
 # Check the UTF-8 of U+12345 CUNEIFORM SIGN URU TIMES KI.
 $AWK 'BEGIN { u12345 = "\360\222\215\205"; exit length(u12345) != 1 }' || {
     { tmp=`(mktemp -d) 2>/dev/null` || {
 	tmp=${TMPDIR-/tmp}/tzselect.$$ &&
 	(umask 77 && mkdir -- "$tmp")
     };} &&
     trap 'status=$?; rm -fr -- "$tmp"; exit $status' 0 HUP INT PIPE TERM &&
     (iconv -f UTF-8 -t //TRANSLIT <"$TZ_COUNTRY_TABLE" >$tmp/iso3166.tab) \
         2>/dev/null &&
     TZ_COUNTRY_TABLE=$tmp/iso3166.tab &&
     iconv -f UTF-8 -t //TRANSLIT <"$TZ_ZONE_TABLE" >$tmp/$zonetabtype.tab &&
     TZ_ZONE_TABLE=$tmp/$zonetabtype.tab
 }
 
 newline='
 '
 IFS=$newline
 
+# Awk script to output a country list.
+output_country_list='
+  BEGIN { FS = "\t" }
+  /^#$/ { next }
+  /^#[^@]/ { next }
+  {
+    commentary = $0 ~ /^#@/
+    if (commentary) {
+      col1ccs = substr($1, 3)
+      conts = $2
+    } else {
+      col1ccs = $1
+      conts = $3
+    }
+    ncc = split(col1ccs, cc, /,/)
+    ncont = split(conts, cont, /,/)
+    for (i = 1; i <= ncc; i++) {
+      elsewhere = commentary
+      for (ci = 1; ci <= ncont; ci++) {
+	if (cont[ci] ~ continent_re) {
+	  if (!cc_seen[cc[i]]++) cc_list[++ccs] = cc[i]
+	  elsewhere = 0
+	}
+      }
+      if (elsewhere) {
+	for (i = 1; i <= ncc; i++) {
+	  cc_elsewhere[cc[i]] = 1
+	}
+      }
+    }
+  }
+  END {
+	  while (getline &2 'Please identify a location' \
 		'so that time zone rules can be set correctly.'
 
 	continent=
 	country=
 	region=
 
 	case $coord in
 	?*)
 		continent=coord;;
 	'')
 
 	# Ask the user for continent or ocean.
 
-	echo >&2 'Please select a continent, ocean, "coord", or "TZ".'
+	echo >&2 'Please select a continent, ocean, "coord", "TZ", or "time".'
 
         quoted_continents=`
 	  $AWK '
 	    function handle_entry(entry) {
 	      entry = substr(entry, 1, index(entry, "/") - 1)
 	      if (entry == "America")
 	       entry = entry "s"
 	      if (entry ~ /^(Arctic|Atlantic|Indian|Pacific)$/)
 	       entry = entry " Ocean"
 	      printf "'\''%s'\''\n", entry
 	    }
 	    BEGIN { FS = "\t" }
 	    /^[^#]/ {
               handle_entry($3)
             }
 	    /^#@/ {
 	      ncont = split($2, cont, /,/)
 	      for (ci = 1; ci <= ncont; ci++) {
 	        handle_entry(cont[ci])
 	      }
 	    }
           ' <"$TZ_ZONE_TABLE" |
 	  sort -u |
 	  tr '\n' ' '
 	  echo ''
 	`
 
 	eval '
 	    doselect '"$quoted_continents"' \
 		"coord - I want to use geographical coordinates." \
-		"TZ - I want to specify the timezone using the Posix TZ format."
+		"TZ - I want to specify the timezone using the Posix TZ format." \
+		"time - I know local time already."
 	    continent=$select_result
 	    case $continent in
 	    Americas) continent=America;;
 	    *" "*) continent=`expr "$continent" : '\''\([^ ]*\)'\''`
 	    esac
 	'
 	esac
 
 	case $continent in
 	TZ)
 		# Ask the user for a Posix TZ string.  Check that it conforms.
 		while
 			echo >&2 'Please enter the desired value' \
 				'of the TZ environment variable.'
 			echo >&2 'For example, AEST-10 is abbreviated' \
 				'AEST and is 10 hours'
 			echo >&2 'ahead (east) of Greenwich,' \
 				'with no daylight saving time.'
 			read TZ
 			$AWK -v TZ="$TZ" 'BEGIN {
 				tzname = "(<[[:alnum:]+-]{3,}>|[[:alpha:]]{3,})"
 				time = "(2[0-4]|[0-1]?[0-9])" \
 				  "(:[0-5][0-9](:[0-5][0-9])?)?"
 				offset = "[-+]?" time
 				mdate = "M([1-9]|1[0-2])\\.[1-5]\\.[0-6]"
 				jdate = "((J[1-9]|[0-9]|J?[1-9][0-9]" \
 				  "|J?[1-2][0-9][0-9])|J?3[0-5][0-9]|J?36[0-5])"
 				datetime = ",(" mdate "|" jdate ")(/" time ")?"
 				tzpattern = "^(:.*|" tzname offset "(" tzname \
 				  "(" offset ")?(" datetime datetime ")?)?)$"
 				if (TZ ~ tzpattern) exit 1
 				exit 0
 			}'
 		do
 		    say >&2 "'$TZ' is not a conforming Posix timezone string."
 		done
 		TZ_for_date=$TZ;;
 	*)
 		case $continent in
 		coord)
 		    case $coord in
 		    '')
 			echo >&2 'Please enter coordinates' \
 				'in ISO 6709 notation.'
 			echo >&2 'For example, +4042-07403 stands for'
 			echo >&2 '40 degrees 42 minutes north,' \
 				'74 degrees 3 minutes west.'
 			read coord;;
 		    esac
 		    distance_table=`$AWK \
 			    -v coord="$coord" \
 			    -v TZ_COUNTRY_TABLE="$TZ_COUNTRY_TABLE" \
-			    "$output_distances" <"$TZ_ZONE_TABLE" |
+			    "$output_distances_or_times" <"$TZ_ZONE_TABLE" |
 		      sort -n |
 		      sed "${location_limit}q"
 		    `
-		    regions=`say "$distance_table" | $AWK '
-		      BEGIN { FS = "\t" }
-		      { print $NF }
+		    regions=`$AWK \
+		      -v distance_table="$distance_table" '
+		      BEGIN {
+		        nlines = split(distance_table, line, /\n/)
+			for (nr = 1; nr <= nlines; nr++) {
+			  nf = split(line[nr], f, /\t/)
+			  print f[nf]
+			}
+		      }
 		    '`
-		    echo >&2 'Please select one of the following timezones,' \
+		    echo >&2 'Please select one of the following timezones,'
 		    echo >&2 'listed roughly in increasing order' \
 			    "of distance from $coord".
 		    doselect $regions
 		    region=$select_result
-		    TZ=`say "$distance_table" | $AWK -v region="$region" '
-		      BEGIN { FS="\t" }
-		      $NF == region { print $4 }
+		    TZ=`$AWK \
+		      -v distance_table="$distance_table" \
+		      -v region="$region" '
+		      BEGIN {
+		        nlines = split(distance_table, line, /\n/)
+			for (nr = 1; nr <= nlines; nr++) {
+			  nf = split(line[nr], f, /\t/)
+			  if (f[nf] == region) {
+			    print f[4]
+			  }
+			}
+		      }
 		    '`
 		    ;;
 		*)
-		# Get list of names of countries in the continent or ocean.
-		countries=`$AWK \
+		case $continent in
+		time)
+		  minute_format='%a %b %d %H:%M'
+		  old_minute=`TZ=UTC0 date +"$minute_format"`
+		  for i in 1 2 3
+		  do
+		    time_table_command=`
+		      $AWK -v output_times=1 \
+			  "$output_distances_or_times" <"$TZ_ZONE_TABLE"
+		    `
+		    time_table=`eval "$time_table_command"`
+		    new_minute=`TZ=UTC0 date +"$minute_format"`
+		    case $old_minute in
+		    "$new_minute") break;;
+		    esac
+		    old_minute=$new_minute
+		  done
+		  echo >&2 "The system says Universal Time is $new_minute."
+		  echo >&2 "Assuming that's correct, what is the local time?"
+		  eval doselect `
+		    say "$time_table" |
+		    sort -k2n -k2,5 -k1n |
+		    $AWK '{
+		      line = $6 " " $7 " " $4 " " $5
+		      if (line == oldline) next
+		      oldline = line
+		      gsub(/'\''/, "&\\\\&&", line)
+		      printf "'\''%s'\''\n", line
+		    }'
+		  `
+		  time=$select_result
+		  zone_table=`
+		    say "$time_table" |
+		    $AWK -v time="$time" '{
+		      if ($6 " " $7 " " $4 " " $5 == time) {
+			sub(/[^\t]*\t/, "")
+			print
+		      }
+		    }'
+		  `
+		  countries=`
+		     say "$zone_table" |
+		     $AWK \
+			-v continent_re='' \
+			-v TZ_COUNTRY_TABLE="$TZ_COUNTRY_TABLE" \
+			"$output_country_list" |
+		     sort -f
+		  `
+		  ;;
+		*)
+		  zone_table=file
+		  # Get list of names of countries in the continent or ocean.
+		  countries=`$AWK \
 			-v continent_re="^$continent/" \
 			-v TZ_COUNTRY_TABLE="$TZ_COUNTRY_TABLE" \
-		'
-			BEGIN { FS = "\t" }
-			/^#$/ { next }
-			/^#[^@]/ { next }
-			{
-			  commentary = $0 ~ /^#@/
-			  if (commentary) {
-			    col1ccs = substr($1, 3)
-			    conts = $2
-			  } else {
-			    col1ccs = $1
-			    conts = $3
-			  }
-			  ncc = split(col1ccs, cc, /,/)
-			  ncont = split(conts, cont, /,/)
-			  for (i = 1; i <= ncc; i++) {
-			    elsewhere = commentary
-			    for (ci = 1; ci <= ncont; ci++) {
-			      if (cont[ci] ~ continent_re) {
-				if (!cc_seen[cc[i]]++) cc_list[++ccs] = cc[i]
-				elsewhere = 0
-			      }
-			    }
-			    if (elsewhere) {
-			      for (i = 1; i <= ncc; i++) {
-			        cc_elsewhere[cc[i]] = 1
-			      }
-			    }
-			  }
-			}
-			END {
-				while (getline &2 'Please select a country' \
 				'whose clocks agree with yours.'
 			doselect $countries
+			country_result=$select_result
 			country=$select_result;;
 		*)
 			country=$countries
 		esac
 
 
 		# Get list of timezones in the country.
-		regions=`$AWK \
+		regions=`
+		  case $zone_table in
+		  file) cat -- "$TZ_ZONE_TABLE";;
+		  *) say "$zone_table";;
+		  esac |
+		  $AWK \
 			-v country="$country" \
 			-v TZ_COUNTRY_TABLE="$TZ_COUNTRY_TABLE" \
-		'
+		    '
 			BEGIN {
 				FS = "\t"
 				cc = country
 				while (getline &2 'Please select one of the following timezones.'
 			doselect $regions
-			region=$select_result;;
-		*)
-			region=$regions
+			region=$select_result
 		esac
 
 		# Determine TZ from country and region.
-		TZ=`$AWK \
+		TZ=`
+		  case $zone_table in
+		  file) cat -- "$TZ_ZONE_TABLE";;
+		  *) say "$zone_table";;
+		  esac |
+		  $AWK \
 			-v country="$country" \
 			-v region="$region" \
 			-v TZ_COUNTRY_TABLE="$TZ_COUNTRY_TABLE" \
-		'
+		    '
 			BEGIN {
 				FS = "\t"
 				cc = country
 				while (getline &2 "$0: time zone files are not set up correctly"
 			exit 1
 		}
 	esac
 
 
 	# Use the proposed TZ to output the current date relative to UTC.
 	# Loop until they agree in seconds.
 	# Give up after 8 unsuccessful tries.
 
 	extra_info=
 	for i in 1 2 3 4 5 6 7 8
 	do
 		TZdate=`LANG=C TZ="$TZ_for_date" date`
 		UTdate=`LANG=C TZ=UTC0 date`
 		TZsec=`expr "$TZdate" : '.*:\([0-5][0-9]\)'`
 		UTsec=`expr "$UTdate" : '.*:\([0-5][0-9]\)'`
 		case $TZsec in
 		$UTsec)
 			extra_info="
 Selected time is now:	$TZdate.
 Universal Time is now:	$UTdate."
 			break
 		esac
 	done
 
 
 	# Output TZ info and ask the user to confirm.
 
 	echo >&2 ""
-	echo >&2 "The following information has been given:"
+	echo >&2 "Based on the following information:"
 	echo >&2 ""
-	case $country%$region%$coord in
-	?*%?*%)	say >&2 "	$country$newline	$region";;
-	?*%%)	say >&2 "	$country";;
-	%?*%?*) say >&2 "	coord $coord$newline	$region";;
-	%%?*)	say >&2 "	coord $coord";;
+	case $time%$country_result%$region%$coord in
+	?*%?*%?*%)
+	  say >&2 "	$time$newline	$country_result$newline	$region";;
+	?*%?*%%|?*%%?*%) say >&2 "	$time$newline	$country_result$region";;
+	?*%%%) say >&2 "	$time";;
+	%?*%?*%) say >&2 "	$country_result$newline	$region";;
+	%?*%%)	say >&2 "	$country_result";;
+	%%?*%?*) say >&2 "	coord $coord$newline	$region";;
+	%%%?*)	say >&2 "	coord $coord";;
 	*)	say >&2 "	TZ='$TZ'"
 	esac
 	say >&2 ""
-	say >&2 "Therefore TZ='$TZ' will be used.$extra_info"
+	say >&2 "TZ='$TZ' will be used.$extra_info"
 	say >&2 "Is the above information OK?"
 
 	doselect Yes No
 	ok=$select_result
 	case $ok in
 	Yes) break
 	esac
 do coord=
 done
 
 case $SHELL in
 *csh) file=.login line="setenv TZ '$TZ'";;
 *) file=.profile line="TZ='$TZ'; export TZ"
 esac
 
 test -t 1 && say >&2 "
 You can make this change permanent for yourself by appending the line
 	$line
 to the file '$file' in your home directory; then log out and log in again.
 
 Here is that TZ value again, this time on standard output so that you
 can use the $0 command in shell scripts:"
 
 say "$TZ"
diff --git a/contrib/tzcode/version b/contrib/tzcode/version
index b74fa117a223..7daa77e00d99 100644
--- a/contrib/tzcode/version
+++ b/contrib/tzcode/version
@@ -1 +1 @@
-2022g
+2023c
diff --git a/contrib/tzcode/zdump.8 b/contrib/tzcode/zdump.8
index 0b9e956526cc..7a78f6b9c040 100644
--- a/contrib/tzcode/zdump.8
+++ b/contrib/tzcode/zdump.8
@@ -1,231 +1,228 @@
 .\" This file is in the public domain, so clarified as of
 .\" 2009-05-17 by Arthur David Olson.
-.\"
-.\" $FreeBSD$
-.\"
 .Dd December 15, 2022
 .Dt ZDUMP 8
 .Os
 .Sh NAME
 .Nm zdump
 .Nd timezone dumper
 .Sh SYNOPSIS
 .Nm
 .Op Fl -help
 .Op Fl -version
 .Op Fl ivV
 .Oo
 .Fl c
 .Op Ar loyear , Ns
 .Ar hiyear
 .Oc
 .Oo
 .Fl t
 .Op Ar lotime , Ns
 .Ar hitime
 .Oc
 .Op Ar timezone ...
 .Sh DESCRIPTION
 The
 .Nm
 program prints the current time in each
 .Ar timezone
 named on the command line.
 .Pp
 The following options are available:
 .Bl -tag -width indent
 .It Fl -version
 Output version information and exit.
 .It Fl -help
 Output short usage message and exit.
 .It Fl i
 Output a description of time intervals.
 For each
 .Ar timezone
 on the command line, output an interval-format description of the
 timezone.
 See
 .Sx "INTERVAL FORMAT"
 below.
 .It Fl v
 Output a verbose description of time intervals.
 For each
 .Ar timezone
 on the command line,
 print the times at the two extreme time values,
 the times (if present) at and just beyond the boundaries of years that
 .Xr localtime 3
 and
 .Xr gmtime 3
 can represent, and
 the times both one second before and exactly at
 each detected time discontinuity.
 Each line is followed by
 .Cm isdst= Ns Ar D
 where
 .Ar D
 is positive, zero, or negative depending on whether
 the given time is daylight saving time, standard time,
 or an unknown time type, respectively.
 Each line is also followed by
 .Cm gmtoff= Ns Ar N
 if the given local time is known to be
 .Ar N
 seconds east of Greenwich.
 .It Fl V
 Like
 .Fl v ,
 except omit output concerning extreme time and year values.
 This generates output that is easier to compare to that of
 implementations with different time representations.
 .It Fl c Oo Ar loyear , Oc Ns Ar hiyear
 Cut off interval output at the given year(s).
 Cutoff times are computed using the proleptic Gregorian calendar with year 0
 and with Universal Time (UT) ignoring leap seconds.
 Cutoffs are at the start of each year, where the lower-bound
 timestamp is inclusive and the upper is exclusive; for example,
 .Ql "-c 1970,2070"
 selects transitions on or after 1970-01-01 00:00:00 UTC
 and before 2070-01-01 00:00:00 UTC.
 The default cutoff is
 .Ql -500,2500 .
 .It Fl t Oo Ar lotime , Oc Ns Ar hitime
 Cut off interval output at the given time(s),
 given in decimal seconds since 1970-01-01 00:00:00
 Coordinated Universal Time (UTC).
 The
 .Ar timezone
 determines whether the count includes leap seconds.
 As with
 .Fl c ,
 the cutoff's lower bound is inclusive and its upper bound is exclusive.
 .El
 .Sh "INTERVAL FORMAT"
 The interval format is a compact text representation that is intended
 to be both human- and machine-readable.
 It consists of an empty line,
 then a line
 .Dq "TZ=\fIstring\fP"
 where
 .Ar string
 is a double-quoted string giving the timezone, a second line
 .Dq "\*- \*- \fIinterval\fP"
 describing the time interval before the first transition if any, and
 zero or more following lines
 .Dq "\fIdate time interval\fP",
 one line for each transition time and following interval.
 Fields are
 separated by single tabs.
 .Pp
 Dates are in
 .Ql "yyyy - mm - dd"
 format and times are in 24-hour
 .Ql "hh : mm : ss"
 format where
 .Ql "hh <24" .
 Times are in local time immediately after the transition.
 A
 time interval description consists of a UT offset in signed
 .Ql "\(+- hhmmss"
 format, a time zone abbreviation, and an isdst flag.
 An abbreviation
 that equals the UT offset is omitted; other abbreviations are
 double-quoted strings unless they consist of one or more alphabetic
 characters.
 An isdst flag is omitted for standard time, and otherwise
 is a decimal integer that is unsigned and positive (typically 1) for
 daylight saving time and negative for unknown.
 .Pp
 In times and in UT offsets with absolute value less than 100 hours,
 the seconds are omitted if they are zero, and
 the minutes are also omitted if they are also zero.
 Positive UT
 offsets are east of Greenwich.
 The UT offset \*-00 denotes a UT
 placeholder in areas where the actual offset is unspecified; by
 convention, this occurs when the UT offset is zero and the time zone
 abbreviation begins with
 .Dq "-"
 or is
 .Dq "zzz".
 .Pp
 In double-quoted strings, escape sequences represent unusual
 characters.
 The escape sequences are \es for space, and \e", \e\e,
 \ef, \en, \er, \et, and \ev with their usual meaning in the C
 programming language.
 E.g., the double-quoted string
 \*(lq"CET\es\e"\e\e"\*(rq represents the character sequence \*(lqCET
 "\e\*(rq.\""
 .Pp
 Here is an example of the output, with the leading empty line omitted.
 (This example is shown with tab stops set far enough apart so that the
 tabbed columns line up.)
 .Bd -literal -offset indent
 TZ="Pacific/Honolulu"
 -	-	-103126	LMT
 1896-01-13	12:01:26	-1030	HST
 1933-04-30	03	-0930	HDT	1
 1933-05-21	11	-1030	HST
 1942-02-09	03	-0930	HWT	1
 1945-08-14	13:30	-0930	HPT	1
 1945-09-30	01	-1030	HST
 1947-06-08	02:30	-10	HST
 .Ed
 .Pp
 Here, local time begins 10 hours, 31 minutes and 26 seconds west of
 UT, and is a standard time abbreviated LMT.
 Immediately after the
 first transition, the date is 1896-01-13 and the time is 12:01:26, and
 the following time interval is 10.5 hours west of UT, a standard time
 abbreviated HST.
 Immediately after the second transition, the date is
 1933-04-30 and the time is 03:00:00 and the following time interval is
 9.5 hours west of UT, is abbreviated HDT, and is daylight saving time.
 Immediately after the last transition the date is 1947-06-08 and the
 time is 02:30:00, and the following time interval is 10 hours west of
 UT, a standard time abbreviated HST.
 .Pp
 Here are excerpts from another example:
 .Bd -literal -offset indent
 TZ="Europe/Astrakhan"
 -	-	+031212	LMT
 1924-04-30	23:47:48	+03
 1930-06-21	01	+04
 1981-04-01	01	+05		1
 1981-09-30	23	+04
 \&...
 2014-10-26	01	+03
 2016-03-27	03	+04
 .Ed
 .Pp
 This time zone is east of UT, so its UT offsets are positive.
 Also,
 many of its time zone abbreviations are omitted since they duplicate
 the text of the UT offset.
 .Sh LIMITATIONS
 Time discontinuities are found by sampling the results returned by
 .Xr localtime 3
 at twelve-hour intervals.
 This works in all real-world cases;
 one can construct artificial time zones for which this fails.
 .Pp
 In the
 .Fl v
 and
 .Fl V
 output,
 .Dq "UT"
 denotes the value returned by
 .Xr gmtime 3 ,
 which uses UTC for modern timestamps and some other UT flavor for
 timestamps that predate the introduction of UTC.
 No attempt is currently made to have the output use
 .Dq "UTC"
 for newer and
 .Dq "UT"
 for older timestamps, partly because the exact date of the
 introduction of UTC is problematic.
 .Sh SEE ALSO
 .Xr tzfile 5 ,
 .Xr zic 8
diff --git a/contrib/tzcode/zdump.c b/contrib/tzcode/zdump.c
index e4ac81cc220c..74ba0639633d 100644
--- a/contrib/tzcode/zdump.c
+++ b/contrib/tzcode/zdump.c
@@ -1,1256 +1,1269 @@
 /* Dump time zone data in a textual format.  */
 
 /*
 ** This file is in the public domain, so clarified as of
 ** 2009-05-17 by Arthur David Olson.
 */
 
 #include "version.h"
 
 #ifndef NETBSD_INSPIRED
 # define NETBSD_INSPIRED 1
 #endif
 
 #include "private.h"
 #include 
 
 #ifndef HAVE_SNPRINTF
-# define HAVE_SNPRINTF (199901 <= __STDC_VERSION__)
+# define HAVE_SNPRINTF (!PORT_TO_C89 || 199901 <= __STDC_VERSION__)
 #endif
 
 #ifndef HAVE_LOCALTIME_R
 # define HAVE_LOCALTIME_R 1
 #endif
 
 #ifndef HAVE_LOCALTIME_RZ
 # ifdef TM_ZONE
 #  define HAVE_LOCALTIME_RZ (NETBSD_INSPIRED && USE_LTZ)
 # else
 #  define HAVE_LOCALTIME_RZ 0
 # endif
 #endif
 
 #ifndef HAVE_TZSET
 # define HAVE_TZSET 1
 #endif
 
 #ifndef ZDUMP_LO_YEAR
 # define ZDUMP_LO_YEAR (-500)
 #endif /* !defined ZDUMP_LO_YEAR */
 
 #ifndef ZDUMP_HI_YEAR
 # define ZDUMP_HI_YEAR 2500
 #endif /* !defined ZDUMP_HI_YEAR */
 
 #define SECSPERNYEAR	(SECSPERDAY * DAYSPERNYEAR)
 #define SECSPERLYEAR	(SECSPERNYEAR + SECSPERDAY)
 #define SECSPER400YEARS	(SECSPERNYEAR * (intmax_t) (300 + 3)	\
 			 + SECSPERLYEAR * (intmax_t) (100 - 3))
 
 /*
 ** True if SECSPER400YEARS is known to be representable as an
 ** intmax_t.  It's OK that SECSPER400YEARS_FITS can in theory be false
 ** even if SECSPER400YEARS is representable, because when that happens
 ** the code merely runs a bit more slowly, and this slowness doesn't
 ** occur on any practical platform.
 */
 enum { SECSPER400YEARS_FITS = SECSPERLYEAR <= INTMAX_MAX / 400 };
 
 #if HAVE_GETTEXT
 # include  /* for setlocale */
 #endif /* HAVE_GETTEXT */
 
 #if ! HAVE_LOCALTIME_RZ
 # undef  timezone_t
 # define timezone_t char **
 #endif
 
 #if !HAVE_POSIX_DECLS
 extern int	getopt(int argc, char * const argv[],
 			const char * options);
 extern char *	optarg;
 extern int	optind;
 #endif
 
 /* The minimum and maximum finite time values.  */
 enum { atime_shift = CHAR_BIT * sizeof(time_t) - 2 };
 static time_t const absolute_min_time =
   ((time_t) -1 < 0
    ? (- ((time_t) ~ (time_t) 0 < 0)
       - (((time_t) 1 << atime_shift) - 1 + ((time_t) 1 << atime_shift)))
    : 0);
 static time_t const absolute_max_time =
   ((time_t) -1 < 0
    ? (((time_t) 1 << atime_shift) - 1 + ((time_t) 1 << atime_shift))
    : -1);
 static size_t	longest;
 static char const *progname;
 static bool	warned;
 static bool	errout;
 
 static char const *abbr(struct tm const *);
-static intmax_t	delta(struct tm *, struct tm *) ATTRIBUTE_REPRODUCIBLE;
+ATTRIBUTE_REPRODUCIBLE static intmax_t delta(struct tm *, struct tm *);
 static void dumptime(struct tm const *);
 static time_t hunt(timezone_t, time_t, time_t, bool);
 static void show(timezone_t, char *, time_t, bool);
 static void showextrema(timezone_t, char *, time_t, struct tm *, time_t);
 static void showtrans(char const *, struct tm const *, time_t, char const *,
 		      char const *);
 static const char *tformat(void);
-static time_t yeartot(intmax_t) ATTRIBUTE_REPRODUCIBLE;
+ATTRIBUTE_REPRODUCIBLE static time_t yeartot(intmax_t);
 
 /* Is C an ASCII digit?  */
 static bool
 is_digit(char c)
 {
   return '0' <= c && c <= '9';
 }
 
 /* Is A an alphabetic character in the C locale?  */
 static bool
 is_alpha(char a)
 {
 	switch (a) {
 	  default:
 		return false;
 	  case 'A': case 'B': case 'C': case 'D': case 'E': case 'F': case 'G':
 	  case 'H': case 'I': case 'J': case 'K': case 'L': case 'M': case 'N':
 	  case 'O': case 'P': case 'Q': case 'R': case 'S': case 'T': case 'U':
 	  case 'V': case 'W': case 'X': case 'Y': case 'Z':
 	  case 'a': case 'b': case 'c': case 'd': case 'e': case 'f': case 'g':
 	  case 'h': case 'i': case 'j': case 'k': case 'l': case 'm': case 'n':
 	  case 'o': case 'p': case 'q': case 'r': case 's': case 't': case 'u':
 	  case 'v': case 'w': case 'x': case 'y': case 'z':
 		return true;
 	}
 }
 
-static ATTRIBUTE_NORETURN void
+ATTRIBUTE_NORETURN static void
 size_overflow(void)
 {
   fprintf(stderr, _("%s: size overflow\n"), progname);
   exit(EXIT_FAILURE);
 }
 
 /* Return A + B, exiting if the result would overflow either ptrdiff_t
-   or size_t.  */
-static ATTRIBUTE_REPRODUCIBLE size_t
-sumsize(size_t a, size_t b)
+   or size_t.  A and B are both nonnegative.  */
+ATTRIBUTE_REPRODUCIBLE static ptrdiff_t
+sumsize(ptrdiff_t a, ptrdiff_t b)
 {
 #ifdef ckd_add
-  size_t sum;
-  if (!ckd_add(&sum, a, b))
+  ptrdiff_t sum;
+  if (!ckd_add(&sum, a, b) && sum <= INDEX_MAX)
     return sum;
 #else
-  if (a <= SIZE_MAX && b <= SIZE_MAX - a)
+  if (a <= INDEX_MAX && b <= INDEX_MAX - a)
     return a + b;
 #endif
   size_overflow();
 }
 
+/* Return the size of of the string STR, including its trailing NUL.
+   Report an error and exit if this would exceed INDEX_MAX which means
+   pointer subtraction wouldn't work.  */
+static ptrdiff_t
+xstrsize(char const *str)
+{
+  size_t len = strlen(str);
+  if (len < INDEX_MAX)
+    return len + 1;
+  size_overflow();
+}
+
 /* Return a pointer to a newly allocated buffer of size SIZE, exiting
-   on failure.  SIZE should be nonzero.  */
-static void * ATTRIBUTE_MALLOC
-xmalloc(size_t size)
+   on failure.  SIZE should be positive.  */
+ATTRIBUTE_MALLOC static void *
+xmalloc(ptrdiff_t size)
 {
   void *p = malloc(size);
   if (!p) {
     fprintf(stderr, _("%s: Memory exhausted\n"), progname);
     exit(EXIT_FAILURE);
   }
   return p;
 }
 
 #if ! HAVE_TZSET
 # undef tzset
 # define tzset zdump_tzset
 static void tzset(void) { }
 #endif
 
 /* Assume gmtime_r works if localtime_r does.
    A replacement localtime_r is defined below if needed.  */
 #if ! HAVE_LOCALTIME_R
 
 # undef gmtime_r
 # define gmtime_r zdump_gmtime_r
 
 static struct tm *
 gmtime_r(time_t *tp, struct tm *tmp)
 {
   struct tm *r = gmtime(tp);
   if (r) {
     *tmp = *r;
     r = tmp;
   }
   return r;
 }
 
 #endif
 
 /* Platforms with TM_ZONE don't need tzname, so they can use the
    faster localtime_rz or localtime_r if available.  */
 
 #if defined TM_ZONE && HAVE_LOCALTIME_RZ
 # define USE_LOCALTIME_RZ true
 #else
 # define USE_LOCALTIME_RZ false
 #endif
 
 #if ! USE_LOCALTIME_RZ
 
 # if !defined TM_ZONE || ! HAVE_LOCALTIME_R || ! HAVE_TZSET
 #  undef localtime_r
 #  define localtime_r zdump_localtime_r
 static struct tm *
 localtime_r(time_t *tp, struct tm *tmp)
 {
   struct tm *r = localtime(tp);
   if (r) {
     *tmp = *r;
     r = tmp;
   }
   return r;
 }
 # endif
 
 # undef localtime_rz
 # define localtime_rz zdump_localtime_rz
 static struct tm *
-localtime_rz(timezone_t rz __unused, time_t *tp, struct tm *tmp)
+localtime_rz(ATTRIBUTE_MAYBE_UNUSED timezone_t rz, time_t *tp, struct tm *tmp)
 {
   return localtime_r(tp, tmp);
 }
 
 # ifdef TYPECHECK
 #  undef mktime_z
 #  define mktime_z zdump_mktime_z
 static time_t
 mktime_z(timezone_t tz, struct tm *tmp)
 {
   return mktime(tmp);
 }
 # endif
 
 # undef tzalloc
 # undef tzfree
 # define tzalloc zdump_tzalloc
 # define tzfree zdump_tzfree
 
 static timezone_t
 tzalloc(char const *val)
 {
 # if HAVE_SETENV
   if (setenv("TZ", val, 1) != 0) {
-    perror("setenv");
+    char const *e = strerror(errno);
+    fprintf(stderr, _("%s: setenv: %s\n"), progname, e);
     exit(EXIT_FAILURE);
   }
   tzset();
   return &optarg;  /* Any valid non-null char ** will do.  */
 # else
   enum { TZeqlen = 3 };
   static char const TZeq[TZeqlen] = "TZ=";
   static char **fakeenv;
   static ptrdiff_t fakeenv0size;
   void *freeable = NULL;
   char **env = fakeenv, **initial_environ;
-  size_t valsize = strlen(val) + 1;
+  ptrdiff_t valsize = xstrsize(val);
   if (fakeenv0size < valsize) {
     char **e = environ, **to;
     ptrdiff_t initial_nenvptrs = 1;  /* Counting the trailing NULL pointer.  */
 
     while (*e++) {
 #  ifdef ckd_add
-      if (ckd_add(&initial_nenvptrs, initial_envptrs, 1)
-	  || SIZE_MAX < initial_envptrs)
+      if (ckd_add(&initial_nenvptrs, initial_nenvptrs, 1)
+	  || INDEX_MAX < initial_nenvptrs)
 	size_overflow();
 #  else
-      if (initial_nenvptrs == min(PTRDIFF_MAX, SIZE_MAX) / sizeof *environ)
+      if (initial_nenvptrs == INDEX_MAX / sizeof *environ)
 	size_overflow();
       initial_nenvptrs++;
 #  endif
     }
     fakeenv0size = sumsize(valsize, valsize);
     fakeenv0size = max(fakeenv0size, 64);
     freeable = env;
     fakeenv = env =
       xmalloc(sumsize(sumsize(sizeof *environ,
 			      initial_nenvptrs * sizeof *environ),
 		      sumsize(TZeqlen, fakeenv0size)));
     to = env + 1;
     for (e = environ; (*to = *e); e++)
       to += strncmp(*e, TZeq, TZeqlen) != 0;
     env[0] = memcpy(to + 1, TZeq, TZeqlen);
   }
   memcpy(env[0] + TZeqlen, val, valsize);
   initial_environ = environ;
   environ = env;
   tzset();
   free(freeable);
   return initial_environ;
 # endif
 }
 
 static void
-tzfree(timezone_t initial_environ)
+tzfree(ATTRIBUTE_MAYBE_UNUSED timezone_t initial_environ)
 {
 # if !HAVE_SETENV
   environ = initial_environ;
   tzset();
 # else
   (void)initial_environ;
 # endif
 }
 #endif /* ! USE_LOCALTIME_RZ */
 
 /* A UT time zone, and its initializer.  */
 static timezone_t gmtz;
 static void
 gmtzinit(void)
 {
   if (USE_LOCALTIME_RZ) {
     /* Try "GMT" first to find out whether this is one of the rare
        platforms where time_t counts leap seconds; this works due to
        the "Zone GMT 0 - GMT" line in the "etcetera" file.  If "GMT"
        fails, fall back on "GMT0" which might be similar due to the
        "Link GMT GMT0" line in the "backward" file, and which
        should work on all POSIX platforms.  The rest of zdump does not
        use the "GMT" abbreviation that comes from this setting, so it
-       is OK to use "GMT" here rather than the more-modern "UTC" which
+       is OK to use "GMT" here rather than the modern "UTC" which
        would not work on platforms that omit the "backward" file.  */
     gmtz = tzalloc("GMT");
     if (!gmtz) {
       static char const gmt0[] = "GMT0";
       gmtz = tzalloc(gmt0);
       if (!gmtz) {
-	perror(gmt0);
+	char const *e = strerror(errno);
+	fprintf(stderr, _("%s: unknown timezone '%s': %s\n"),
+		progname, gmt0, e);
 	exit(EXIT_FAILURE);
       }
     }
   }
 }
 
 /* Convert *TP to UT, storing the broken-down time into *TMP.
    Return TMP if successful, NULL otherwise.  This is like gmtime_r(TP, TMP),
    except typically faster if USE_LOCALTIME_RZ.  */
 static struct tm *
 my_gmtime_r(time_t *tp, struct tm *tmp)
 {
   return USE_LOCALTIME_RZ ? localtime_rz(gmtz, tp, tmp) : gmtime_r(tp, tmp);
 }
 
 #ifndef TYPECHECK
 # define my_localtime_rz localtime_rz
 #else /* !defined TYPECHECK */
 
 static struct tm *
 my_localtime_rz(timezone_t tz, time_t *tp, struct tm *tmp)
 {
 	tmp = localtime_rz(tz, tp, tmp);
 	if (tmp) {
 		struct tm	tm;
 		register time_t	t;
 
 		tm = *tmp;
 		t = mktime_z(tz, &tm);
 		if (t != *tp) {
 			fflush(stdout);
 			fprintf(stderr, "\n%s: ", progname);
 			fprintf(stderr, tformat(), *tp);
 			fprintf(stderr, " ->");
 			fprintf(stderr, " year=%d", tmp->tm_year);
 			fprintf(stderr, " mon=%d", tmp->tm_mon);
 			fprintf(stderr, " mday=%d", tmp->tm_mday);
 			fprintf(stderr, " hour=%d", tmp->tm_hour);
 			fprintf(stderr, " min=%d", tmp->tm_min);
 			fprintf(stderr, " sec=%d", tmp->tm_sec);
 			fprintf(stderr, " isdst=%d", tmp->tm_isdst);
 			fprintf(stderr, " -> ");
 			fprintf(stderr, tformat(), t);
 			fprintf(stderr, "\n");
 			errout = true;
 		}
 	}
 	return tmp;
 }
 #endif /* !defined TYPECHECK */
 
 static void
 abbrok(const char *const abbrp, const char *const zone)
 {
 	register const char *	cp;
 	register const char *	wp;
 
 	if (warned)
 		return;
 	cp = abbrp;
 	while (is_alpha(*cp) || is_digit(*cp) || *cp == '-' || *cp == '+')
 		++cp;
 	if (*cp)
 	  wp = _("has characters other than ASCII alphanumerics, '-' or '+'");
 	else if (cp - abbrp < 3)
 	  wp = _("has fewer than 3 characters");
 	else if (cp - abbrp > 6)
 	  wp = _("has more than 6 characters");
 	else
 	  return;
 	fflush(stdout);
 	fprintf(stderr,
 		_("%s: warning: zone \"%s\" abbreviation \"%s\" %s\n"),
 		progname, zone, abbrp, wp);
 	warned = errout = true;
 }
 
 /* Return a time zone abbreviation.  If the abbreviation needs to be
    saved, use *BUF (of size *BUFALLOC) to save it, and return the
-   abbreviation in the possibly-reallocated *BUF.  Otherwise, just
+   abbreviation in the possibly reallocated *BUF.  Otherwise, just
    return the abbreviation.  Get the abbreviation from TMP.
    Exit on memory allocation failure.  */
 static char const *
 saveabbr(char **buf, ptrdiff_t *bufalloc, struct tm const *tmp)
 {
   char const *ab = abbr(tmp);
   if (HAVE_LOCALTIME_RZ)
     return ab;
   else {
-    size_t ablen = strlen(ab);
-    if ((size_t)*bufalloc <= ablen) {
+    ptrdiff_t absize = xstrsize(ab);
+    if (*bufalloc < absize) {
       free(*buf);
 
       /* Make the new buffer at least twice as long as the old,
 	 to avoid O(N**2) behavior on repeated calls.  */
-      *bufalloc = sumsize(*bufalloc, ablen + 1);
+      *bufalloc = sumsize(*bufalloc, absize);
 
       *buf = xmalloc(*bufalloc);
     }
     return strcpy(*buf, ab);
   }
 }
 
 static void
 close_file(FILE *stream)
 {
   char const *e = (ferror(stream) ? _("I/O error")
 		   : fclose(stream) != 0 ? strerror(errno) : NULL);
   if (e) {
     fprintf(stderr, "%s: %s\n", progname, e);
     exit(EXIT_FAILURE);
   }
 }
 
 static void
 usage(FILE * const stream, const int status)
 {
 	fprintf(stream,
 _("%s: usage: %s OPTIONS TIMEZONE ...\n"
   "Options include:\n"
   "  -c [L,]U   Start at year L (default -500), end before year U (default 2500)\n"
   "  -t [L,]U   Start at time L, end before time U (in seconds since 1970)\n"
   "  -i         List transitions briefly (format is experimental)\n" \
   "  -v         List transitions verbosely\n"
   "  -V         List transitions a bit less verbosely\n"
   "  --help     Output this help\n"
   "  --version  Output version info\n"
   "\n"
   "Report bugs to %s.\n"),
 		progname, progname, REPORT_BUGS_TO);
 	if (status == EXIT_SUCCESS)
 	  close_file(stream);
 	exit(status);
 }
 
 int
 main(int argc, char *argv[])
 {
 	/* These are static so that they're initially zero.  */
 	static char *		abbrev;
 	static ptrdiff_t	abbrevsize;
 
 	register int		i;
 	register bool		vflag;
 	register bool		Vflag;
 	register char *		cutarg;
 	register char *		cuttimes;
 	register time_t		cutlotime;
 	register time_t		cuthitime;
 	time_t			now;
 	bool iflag = false;
 
 	cutlotime = absolute_min_time;
 	cuthitime = absolute_max_time;
 #if HAVE_GETTEXT
 	setlocale(LC_ALL, "");
 # ifdef TZ_DOMAINDIR
 	bindtextdomain(TZ_DOMAIN, TZ_DOMAINDIR);
 # endif /* defined TEXTDOMAINDIR */
 	textdomain(TZ_DOMAIN);
 #endif /* HAVE_GETTEXT */
 	progname = argv[0] ? argv[0] : "zdump";
 	for (i = 1; i < argc; ++i)
 		if (strcmp(argv[i], "--version") == 0) {
 			printf("zdump %s%s\n", PKGVERSION, TZVERSION);
 			return EXIT_SUCCESS;
 		} else if (strcmp(argv[i], "--help") == 0) {
 			usage(stdout, EXIT_SUCCESS);
 		}
 	vflag = Vflag = false;
 	cutarg = cuttimes = NULL;
 	for (;;)
 	  switch (getopt(argc, argv, "c:it:vV")) {
 	  case 'c': cutarg = optarg; break;
 	  case 't': cuttimes = optarg; break;
 	  case 'i': iflag = true; break;
 	  case 'v': vflag = true; break;
 	  case 'V': Vflag = true; break;
 	  case -1:
 	    if (! (optind == argc - 1 && strcmp(argv[optind], "=") == 0))
 	      goto arg_processing_done;
 	    ATTRIBUTE_FALLTHROUGH;
 	  default:
 	    usage(stderr, EXIT_FAILURE);
 	  }
  arg_processing_done:;
 
 	if (iflag | vflag | Vflag) {
 		intmax_t	lo;
 		intmax_t	hi;
 		char *loend, *hiend;
 		register intmax_t cutloyear = ZDUMP_LO_YEAR;
 		register intmax_t cuthiyear = ZDUMP_HI_YEAR;
 		if (cutarg != NULL) {
 			lo = strtoimax(cutarg, &loend, 10);
 			if (cutarg != loend && !*loend) {
 				hi = lo;
 				cuthiyear = hi;
 			} else if (cutarg != loend && *loend == ','
 				   && (hi = strtoimax(loend + 1, &hiend, 10),
 				       loend + 1 != hiend && !*hiend)) {
 				cutloyear = lo;
 				cuthiyear = hi;
 			} else {
 				fprintf(stderr, _("%s: wild -c argument %s\n"),
 					progname, cutarg);
 				return EXIT_FAILURE;
 			}
 		}
 		if (cutarg != NULL || cuttimes == NULL) {
 			cutlotime = yeartot(cutloyear);
 			cuthitime = yeartot(cuthiyear);
 		}
 		if (cuttimes != NULL) {
 			lo = strtoimax(cuttimes, &loend, 10);
 			if (cuttimes != loend && !*loend) {
 				hi = lo;
 				if (hi < cuthitime) {
 					if (hi < absolute_min_time + 1)
 					  hi = absolute_min_time + 1;
 					cuthitime = hi;
 				}
 			} else if (cuttimes != loend && *loend == ','
 				   && (hi = strtoimax(loend + 1, &hiend, 10),
 				       loend + 1 != hiend && !*hiend)) {
 				if (cutlotime < lo) {
 					if (absolute_max_time < lo)
 						lo = absolute_max_time;
 					cutlotime = lo;
 				}
 				if (hi < cuthitime) {
 					if (hi < absolute_min_time + 1)
 					  hi = absolute_min_time + 1;
 					cuthitime = hi;
 				}
 			} else {
 				fprintf(stderr,
 					_("%s: wild -t argument %s\n"),
 					progname, cuttimes);
 				return EXIT_FAILURE;
 			}
 		}
 	}
 	gmtzinit();
 	if (iflag | vflag | Vflag)
 	  now = 0;
 	else {
 	  now = time(NULL);
 	  now |= !now;
 	}
 	longest = 0;
 	for (i = optind; i < argc; i++) {
 	  size_t arglen = strlen(argv[i]);
 	  if (longest < arglen)
 	    longest = min(arglen, INT_MAX);
 	}
 
 	for (i = optind; i < argc; ++i) {
 		timezone_t tz = tzalloc(argv[i]);
 		char const *ab;
 		time_t t;
 		struct tm tm, newtm;
 		bool tm_ok;
 		if (!tz) {
-		  perror(argv[i]);
+		  char const *e = strerror(errno);
+		  fprintf(stderr, _("%s: unknown timezone '%s': %s\n"),
+			  progname, argv[1], e);
 		  return EXIT_FAILURE;
 		}
 		if (now) {
 			show(tz, argv[i], now, false);
 			tzfree(tz);
 			continue;
 		}
 		warned = false;
 		t = absolute_min_time;
 		if (! (iflag | Vflag)) {
 			show(tz, argv[i], t, true);
 			if (my_localtime_rz(tz, &t, &tm) == NULL
 			    && t < cutlotime) {
 				time_t newt = cutlotime;
 				if (my_localtime_rz(tz, &newt, &newtm) != NULL)
 				  showextrema(tz, argv[i], t, NULL, newt);
 			}
 		}
 		if (t + 1 < cutlotime)
 		  t = cutlotime - 1;
 		tm_ok = my_localtime_rz(tz, &t, &tm) != NULL;
 		if (tm_ok) {
 		  ab = saveabbr(&abbrev, &abbrevsize, &tm);
 		  if (iflag) {
 		    showtrans("\nTZ=%f", &tm, t, ab, argv[i]);
 		    showtrans("-\t-\t%Q", &tm, t, ab, argv[i]);
 		  }
 		} else
 		  ab = NULL;
 		while (t < cuthitime - 1) {
 		  time_t newt = ((t < absolute_max_time - SECSPERDAY / 2
 				  && t + SECSPERDAY / 2 < cuthitime - 1)
 				 ? t + SECSPERDAY / 2
 				 : cuthitime - 1);
 		  struct tm *newtmp = localtime_rz(tz, &newt, &newtm);
 		  bool newtm_ok = newtmp != NULL;
 		  if (tm_ok != newtm_ok
 		      || (ab && (delta(&newtm, &tm) != newt - t
 				 || newtm.tm_isdst != tm.tm_isdst
 				 || strcmp(abbr(&newtm), ab) != 0))) {
 		    newt = hunt(tz, t, newt, false);
 		    newtmp = localtime_rz(tz, &newt, &newtm);
 		    newtm_ok = newtmp != NULL;
 		    if (iflag)
 		      showtrans("%Y-%m-%d\t%L\t%Q", newtmp, newt,
 				newtm_ok ? abbr(&newtm) : NULL, argv[i]);
 		    else {
 		      show(tz, argv[i], newt - 1, true);
 		      show(tz, argv[i], newt, true);
 		    }
 		  }
 		  t = newt;
 		  tm_ok = newtm_ok;
 		  if (newtm_ok) {
 		    ab = saveabbr(&abbrev, &abbrevsize, &newtm);
 		    tm = newtm;
 		  }
 		}
 		if (! (iflag | Vflag)) {
 			time_t newt = absolute_max_time;
 			t = cuthitime;
 			if (t < newt) {
 			  struct tm *tmp = my_localtime_rz(tz, &t, &tm);
 			  if (tmp != NULL
 			      && my_localtime_rz(tz, &newt, &newtm) == NULL)
 			    showextrema(tz, argv[i], t, tmp, newt);
 			}
 			show(tz, argv[i], absolute_max_time, true);
 		}
 		tzfree(tz);
 	}
 	close_file(stdout);
 	if (errout && (ferror(stderr) || fclose(stderr) != 0))
 	  return EXIT_FAILURE;
 	return EXIT_SUCCESS;
 }
 
 static time_t
 yeartot(intmax_t y)
 {
 	register intmax_t	myy, seconds, years;
 	register time_t		t;
 
 	myy = EPOCH_YEAR;
 	t = 0;
 	while (myy < y) {
 		if (SECSPER400YEARS_FITS && 400 <= y - myy) {
 			intmax_t diff400 = (y - myy) / 400;
 			if (INTMAX_MAX / SECSPER400YEARS < diff400)
 				return absolute_max_time;
 			seconds = diff400 * SECSPER400YEARS;
 			years = diff400 * 400;
                 } else {
 			seconds = isleap(myy) ? SECSPERLYEAR : SECSPERNYEAR;
 			years = 1;
 		}
 		myy += years;
 		if (t > absolute_max_time - seconds)
 			return absolute_max_time;
 		t += seconds;
 	}
 	while (y < myy) {
 		if (SECSPER400YEARS_FITS && y + 400 <= myy && myy < 0) {
 			intmax_t diff400 = (myy - y) / 400;
 			if (INTMAX_MAX / SECSPER400YEARS < diff400)
 				return absolute_min_time;
 			seconds = diff400 * SECSPER400YEARS;
 			years = diff400 * 400;
 		} else {
 			seconds = isleap(myy - 1) ? SECSPERLYEAR : SECSPERNYEAR;
 			years = 1;
 		}
 		myy -= years;
 		if (t < absolute_min_time + seconds)
 			return absolute_min_time;
 		t -= seconds;
 	}
 	return t;
 }
 
 /* Search for a discontinuity in timezone TZ, in the
    timestamps ranging from LOT through HIT.  LOT and HIT disagree
    about some aspect of timezone.  If ONLY_OK, search only for
    definedness changes, i.e., localtime succeeds on one side of the
    transition but fails on the other side.  Return the timestamp just
    before the transition from LOT's settings.  */
 
 static time_t
 hunt(timezone_t tz, time_t lot, time_t hit, bool only_ok)
 {
 	static char *		loab;
 	static ptrdiff_t	loabsize;
 	struct tm		lotm;
 	struct tm		tm;
 
 	/* Convert LOT into a broken-down time here, even though our
 	   caller already did that.  On platforms without TM_ZONE,
 	   tzname may have been altered since our caller broke down
 	   LOT, and tzname needs to be changed back.  */
 	bool lotm_ok = my_localtime_rz(tz, &lot, &lotm) != NULL;
 	bool tm_ok;
 	char const *ab = lotm_ok ? saveabbr(&loab, &loabsize, &lotm) : NULL;
 
 	for ( ; ; ) {
 		/* T = average of LOT and HIT, rounding down.
-		   Avoid overflow, even on oddball C89 platforms
-		   where / rounds down and TIME_T_MIN == -TIME_T_MAX
-		   so lot / 2 + hit / 2 might overflow.  */
-		time_t t = (lot / 2
-			    - ((lot % 2 + hit % 2) < 0)
-			    + ((lot % 2 + hit % 2) == 2)
-			    + hit / 2);
+		   Avoid overflow.  */
+		int rem_sum = lot % 2 + hit % 2;
+		time_t t = (rem_sum == 2) - (rem_sum < 0) + lot / 2 + hit / 2;
 		if (t == lot)
 			break;
 		tm_ok = my_localtime_rz(tz, &t, &tm) != NULL;
 		if (lotm_ok == tm_ok
 		    && (only_ok
 			|| (ab && tm.tm_isdst == lotm.tm_isdst
 			    && delta(&tm, &lotm) == t - lot
 			    && strcmp(abbr(&tm), ab) == 0))) {
 		  lot = t;
 		  if (tm_ok)
 		    lotm = tm;
 		} else	hit = t;
 	}
 	return hit;
 }
 
 /*
 ** Thanks to Paul Eggert for logic used in delta_nonneg.
 */
 
 static intmax_t
 delta_nonneg(struct tm *newp, struct tm *oldp)
 {
 	intmax_t oldy = oldp->tm_year;
 	int cycles = (newp->tm_year - oldy) / YEARSPERREPEAT;
 	intmax_t sec = SECSPERREPEAT, result = cycles * sec;
 	int tmy = oldp->tm_year + cycles * YEARSPERREPEAT;
 	for ( ; tmy < newp->tm_year; ++tmy)
 		result += DAYSPERNYEAR + isleap_sum(tmy, TM_YEAR_BASE);
 	result += newp->tm_yday - oldp->tm_yday;
 	result *= HOURSPERDAY;
 	result += newp->tm_hour - oldp->tm_hour;
 	result *= MINSPERHOUR;
 	result += newp->tm_min - oldp->tm_min;
 	result *= SECSPERMIN;
 	result += newp->tm_sec - oldp->tm_sec;
 	return result;
 }
 
 static intmax_t
 delta(struct tm *newp, struct tm *oldp)
 {
   return (newp->tm_year < oldp->tm_year
 	  ? -delta_nonneg(oldp, newp)
 	  : delta_nonneg(newp, oldp));
 }
 
 #ifndef TM_GMTOFF
 /* Return A->tm_yday, adjusted to compare it fairly to B->tm_yday.
    Assume A and B differ by at most one year.  */
 static int
 adjusted_yday(struct tm const *a, struct tm const *b)
 {
   int yday = a->tm_yday;
   if (b->tm_year < a->tm_year)
     yday += 365 + isleap_sum(b->tm_year, TM_YEAR_BASE);
   return yday;
 }
 #endif
 
 /* If A is the broken-down local time and B the broken-down UT for
    the same instant, return A's UT offset in seconds, where positive
    offsets are east of Greenwich.  On failure, return LONG_MIN.
 
    If T is nonnull, *T is the timestamp that corresponds to A; call
    my_gmtime_r and use its result instead of B.  Otherwise, B is the
    possibly nonnull result of an earlier call to my_gmtime_r.  */
 static long
 gmtoff(struct tm const *a, ATTRIBUTE_MAYBE_UNUSED time_t *t,
        ATTRIBUTE_MAYBE_UNUSED struct tm const *b)
 {
 #ifdef TM_GMTOFF
   return a->TM_GMTOFF;
 #else
   struct tm tm;
   if (t)
     b = my_gmtime_r(t, &tm);
   if (! b)
     return LONG_MIN;
   else {
     int ayday = adjusted_yday(a, b);
     int byday = adjusted_yday(b, a);
     int days = ayday - byday;
     long hours = a->tm_hour - b->tm_hour + 24 * days;
     long minutes = a->tm_min - b->tm_min + 60 * hours;
     long seconds = a->tm_sec - b->tm_sec + 60 * minutes;
     return seconds;
   }
 #endif
 }
 
 static void
 show(timezone_t tz, char *zone, time_t t, bool v)
 {
 	register struct tm *	tmp;
 	register struct tm *	gmtmp;
 	struct tm tm, gmtm;
 
 	printf("%-*s  ", (int)longest, zone);
 	if (v) {
 		gmtmp = my_gmtime_r(&t, &gmtm);
 		if (gmtmp == NULL) {
 			printf(tformat(), t);
 			printf(_(" (gmtime failed)"));
 		} else {
 			dumptime(gmtmp);
 			printf(" UT");
 		}
 		printf(" = ");
 	}
 	tmp = my_localtime_rz(tz, &t, &tm);
 	if (tmp == NULL) {
 		printf(tformat(), t);
 		printf(_(" (localtime failed)"));
 	} else {
 		dumptime(tmp);
 		if (*abbr(tmp) != '\0')
 			printf(" %s", abbr(tmp));
 		if (v) {
 			long off = gmtoff(tmp, NULL, gmtmp);
 			printf(" isdst=%d", tmp->tm_isdst);
 			if (off != LONG_MIN)
 			  printf(" gmtoff=%ld", off);
 		}
 	}
 	printf("\n");
 	if (tmp != NULL && *abbr(tmp) != '\0')
 		abbrok(abbr(tmp), zone);
 }
 
 /* Show timestamps just before and just after a transition between
    defined and undefined (or vice versa) in either localtime or
    gmtime.  These transitions are for timezone TZ with name ZONE, in
    the range from LO (with broken-down time LOTMP if that is nonnull)
    through HI.  LO and HI disagree on definedness.  */
 
 static void
 showextrema(timezone_t tz, char *zone, time_t lo, struct tm *lotmp, time_t hi)
 {
   struct tm localtm[2], gmtm[2];
   time_t t, boundary = hunt(tz, lo, hi, true);
   bool old = false;
   hi = (SECSPERDAY < hi - boundary
 	? boundary + SECSPERDAY
 	: hi + (hi < TIME_T_MAX));
   if (SECSPERDAY < boundary - lo) {
     lo = boundary - SECSPERDAY;
     lotmp = my_localtime_rz(tz, &lo, &localtm[old]);
   }
   if (lotmp)
     localtm[old] = *lotmp;
   else
     localtm[old].tm_sec = -1;
   if (! my_gmtime_r(&lo, &gmtm[old]))
     gmtm[old].tm_sec = -1;
 
   /* Search sequentially for definedness transitions.  Although this
      could be sped up by refining 'hunt' to search for either
      localtime or gmtime definedness transitions, it hardly seems
      worth the trouble.  */
   for (t = lo + 1; t < hi; t++) {
     bool new = !old;
     if (! my_localtime_rz(tz, &t, &localtm[new]))
       localtm[new].tm_sec = -1;
     if (! my_gmtime_r(&t, &gmtm[new]))
       gmtm[new].tm_sec = -1;
     if (((localtm[old].tm_sec < 0) != (localtm[new].tm_sec < 0))
 	| ((gmtm[old].tm_sec < 0) != (gmtm[new].tm_sec < 0))) {
       show(tz, zone, t - 1, true);
       show(tz, zone, t, true);
     }
     old = new;
   }
 }
 
 #if HAVE_SNPRINTF
 # define my_snprintf snprintf
 #else
 # include 
 
 /* A substitute for snprintf that is good enough for zdump.  */
-static int ATTRIBUTE_FORMAT((printf, 3, 4))
+ATTRIBUTE_FORMAT((printf, 3, 4)) static int
 my_snprintf(char *s, size_t size, char const *format, ...)
 {
   int n;
   va_list args;
   char const *arg;
   size_t arglen, slen;
   char buf[1024];
   va_start(args, format);
   if (strcmp(format, "%s") == 0) {
     arg = va_arg(args, char const *);
     arglen = strlen(arg);
   } else {
     n = vsprintf(buf, format, args);
     if (n < 0) {
       va_end(args);
       return n;
     }
     arg = buf;
     arglen = n;
   }
   slen = arglen < size ? arglen : size - 1;
   memcpy(s, arg, slen);
   s[slen] = '\0';
   n = arglen <= INT_MAX ? arglen : -1;
   va_end(args);
   return n;
 }
 #endif
 
 /* Store into BUF, of size SIZE, a formatted local time taken from *TM.
    Use ISO 8601 format +HH:MM:SS.  Omit :SS if SS is zero, and omit
    :MM too if MM is also zero.
 
    Return the length of the resulting string.  If the string does not
    fit, return the length that the string would have been if it had
    fit; do not overrun the output buffer.  */
 static int
 format_local_time(char *buf, ptrdiff_t size, struct tm const *tm)
 {
   int ss = tm->tm_sec, mm = tm->tm_min, hh = tm->tm_hour;
   return (ss
 	  ? my_snprintf(buf, size, "%02d:%02d:%02d", hh, mm, ss)
 	  : mm
 	  ? my_snprintf(buf, size, "%02d:%02d", hh, mm)
 	  : my_snprintf(buf, size, "%02d", hh));
 }
 
 /* Store into BUF, of size SIZE, a formatted UT offset for the
    localtime *TM corresponding to time T.  Use ISO 8601 format
    +HHMMSS, or -HHMMSS for timestamps west of Greenwich; use the
    format -00 for unknown UT offsets.  If the hour needs more than
    two digits to represent, extend the length of HH as needed.
    Otherwise, omit SS if SS is zero, and omit MM too if MM is also
    zero.
 
    Return the length of the resulting string, or -1 if the result is
    not representable as a string.  If the string does not fit, return
    the length that the string would have been if it had fit; do not
    overrun the output buffer.  */
 static int
 format_utc_offset(char *buf, ptrdiff_t size, struct tm const *tm, time_t t)
 {
   long off = gmtoff(tm, &t, NULL);
   char sign = ((off < 0
 		|| (off == 0
 		    && (*abbr(tm) == '-' || strcmp(abbr(tm), "zzz") == 0)))
 	       ? '-' : '+');
   long hh;
   int mm, ss;
   if (off < 0)
     {
       if (off == LONG_MIN)
 	return -1;
       off = -off;
     }
   ss = off % 60;
   mm = off / 60 % 60;
   hh = off / 60 / 60;
   return (ss || 100 <= hh
 	  ? my_snprintf(buf, size, "%c%02ld%02d%02d", sign, hh, mm, ss)
 	  : mm
 	  ? my_snprintf(buf, size, "%c%02ld%02d", sign, hh, mm)
 	  : my_snprintf(buf, size, "%c%02ld", sign, hh));
 }
 
 /* Store into BUF (of size SIZE) a quoted string representation of P.
    If the representation's length is less than SIZE, return the
    length; the representation is not null terminated.  Otherwise
    return SIZE, to indicate that BUF is too small.  */
 static ptrdiff_t
 format_quoted_string(char *buf, ptrdiff_t size, char const *p)
 {
   char *b = buf;
   ptrdiff_t s = size;
   if (!s)
     return size;
   *b++ = '"', s--;
   for (;;) {
     char c = *p++;
     if (s <= 1)
       return size;
     switch (c) {
     default: *b++ = c, s--; continue;
     case '\0': *b++ = '"', s--; return size - s;
     case '"': case '\\': break;
     case ' ': c = 's'; break;
     case '\f': c = 'f'; break;
     case '\n': c = 'n'; break;
     case '\r': c = 'r'; break;
     case '\t': c = 't'; break;
     case '\v': c = 'v'; break;
     }
     *b++ = '\\', *b++ = c, s -= 2;
   }
 }
 
 /* Store into BUF (of size SIZE) a timestamp formatted by TIME_FMT.
    TM is the broken-down time, T the seconds count, AB the time zone
    abbreviation, and ZONE_NAME the zone name.  Return true if
    successful, false if the output would require more than SIZE bytes.
    TIME_FMT uses the same format that strftime uses, with these
    additions:
 
    %f zone name
    %L local time as per format_local_time
    %Q like "U\t%Z\tD" where U is the UT offset as for format_utc_offset
       and D is the isdst flag; except omit D if it is zero, omit %Z if
       it equals U, quote and escape %Z if it contains nonalphabetics,
       and omit any trailing tabs.  */
 
 static bool
 istrftime(char *buf, ptrdiff_t size, char const *time_fmt,
 	  struct tm const *tm, time_t t, char const *ab, char const *zone_name)
 {
   char *b = buf;
   ptrdiff_t s = size;
   char const *f = time_fmt, *p;
 
   for (p = f; ; p++)
     if (*p == '%' && p[1] == '%')
       p++;
     else if (!*p
 	     || (*p == '%'
 		 && (p[1] == 'f' || p[1] == 'L' || p[1] == 'Q'))) {
       ptrdiff_t formatted_len;
       ptrdiff_t f_prefix_len = p - f;
       ptrdiff_t f_prefix_copy_size = sumsize(f_prefix_len, 2);
       char fbuf[100];
       bool oversized = sizeof fbuf <= (size_t)f_prefix_copy_size;
       char *f_prefix_copy = oversized ? xmalloc(f_prefix_copy_size) : fbuf;
       memcpy(f_prefix_copy, f, f_prefix_len);
       strcpy(f_prefix_copy + f_prefix_len, "X");
       formatted_len = strftime(b, s, f_prefix_copy, tm);
       if (oversized)
 	free(f_prefix_copy);
       if (formatted_len == 0)
 	return false;
       formatted_len--;
       b += formatted_len, s -= formatted_len;
       if (!*p++)
 	break;
       switch (*p) {
       case 'f':
 	formatted_len = format_quoted_string(b, s, zone_name);
 	break;
       case 'L':
 	formatted_len = format_local_time(b, s, tm);
 	break;
       case 'Q':
 	{
 	  bool show_abbr;
 	  int offlen = format_utc_offset(b, s, tm, t);
 	  if (! (0 <= offlen && offlen < s))
 	    return false;
 	  show_abbr = strcmp(b, ab) != 0;
 	  b += offlen, s -= offlen;
 	  if (show_abbr) {
 	    char const *abp;
 	    ptrdiff_t len;
 	    if (s <= 1)
 	      return false;
 	    *b++ = '\t', s--;
 	    for (abp = ab; is_alpha(*abp); abp++)
 	      continue;
 	    len = (!*abp && *ab
 		   ? my_snprintf(b, s, "%s", ab)
 		   : format_quoted_string(b, s, ab));
 	    if (s <= len)
 	      return false;
 	    b += len, s -= len;
 	  }
 	  formatted_len
 	    = (tm->tm_isdst
 	       ? my_snprintf(b, s, &"\t\t%d"[show_abbr], tm->tm_isdst)
 	       : 0);
 	}
 	break;
       }
       if (s <= formatted_len)
 	return false;
       b += formatted_len, s -= formatted_len;
       f = p + 1;
     }
   *b = '\0';
   return true;
 }
 
 /* Show a time transition.  */
 static void
 showtrans(char const *time_fmt, struct tm const *tm, time_t t, char const *ab,
 	  char const *zone_name)
 {
   if (!tm) {
     printf(tformat(), t);
     putchar('\n');
   } else {
     char stackbuf[1000];
     ptrdiff_t size = sizeof stackbuf;
     char *buf = stackbuf;
     char *bufalloc = NULL;
     while (! istrftime(buf, size, time_fmt, tm, t, ab, zone_name)) {
       size = sumsize(size, size);
       free(bufalloc);
       buf = bufalloc = xmalloc(size);
     }
     puts(buf);
     free(bufalloc);
   }
 }
 
 static char const *
 abbr(struct tm const *tmp)
 {
 #ifdef TM_ZONE
 	return tmp->TM_ZONE;
 #else
 # if HAVE_TZNAME
 	if (0 <= tmp->tm_isdst && tzname[0 < tmp->tm_isdst])
 	  return tzname[0 < tmp->tm_isdst];
 # endif
 	return "";
 #endif
 }
 
 /*
 ** The code below can fail on certain theoretical systems;
 ** it works on all known real-world systems as of 2022-01-25.
 */
 
 static const char *
 tformat(void)
 {
-#if HAVE_GENERIC
+#if HAVE__GENERIC
 	/* C11-style _Generic is more likely to return the correct
 	   format when distinct types have the same size.  */
 	char const *fmt =
 	  _Generic(+ (time_t) 0,
 		   int: "%d", long: "%ld", long long: "%lld",
 		   unsigned: "%u", unsigned long: "%lu",
 		   unsigned long long: "%llu",
 		   default: NULL);
 	if (fmt)
 	  return fmt;
 	fmt = _Generic((time_t) 0,
 		       intmax_t: "%"PRIdMAX, uintmax_t: "%"PRIuMAX,
 		       default: NULL);
 	if (fmt)
 	  return fmt;
 #endif
 	if (0 > (time_t) -1) {		/* signed */
 		if (sizeof(time_t) == sizeof(intmax_t))
 			return "%"PRIdMAX;
 		if (sizeof(time_t) > sizeof(long))
 			return "%lld";
 		if (sizeof(time_t) > sizeof(int))
 			return "%ld";
 		return "%d";
 	}
 #ifdef PRIuMAX
 	if (sizeof(time_t) == sizeof(uintmax_t))
 		return "%"PRIuMAX;
 #endif
 	if (sizeof(time_t) > sizeof(unsigned long))
 		return "%llu";
 	if (sizeof(time_t) > sizeof(unsigned int))
 		return "%lu";
 	return "%u";
 }
 
 static void
 dumptime(register const struct tm *timeptr)
 {
 	static const char	wday_name[][4] = {
 		"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
 	};
 	static const char	mon_name[][4] = {
 		"Jan", "Feb", "Mar", "Apr", "May", "Jun",
 		"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
 	};
 	register int		lead;
 	register int		trail;
 	int DIVISOR = 10;
 
 	/*
 	** The packaged localtime_rz and gmtime_r never put out-of-range
 	** values in tm_wday or tm_mon, but since this code might be compiled
 	** with other (perhaps experimental) versions, paranoia is in order.
 	*/
 	printf("%s %s%3d %.2d:%.2d:%.2d ",
 		((0 <= timeptr->tm_wday
 		  && timeptr->tm_wday < (int)(sizeof wday_name / sizeof wday_name[0]))
 		 ? wday_name[timeptr->tm_wday] : "???"),
 		((0 <= timeptr->tm_mon
 		  && timeptr->tm_mon < (int)(sizeof mon_name / sizeof mon_name[0]))
 		 ? mon_name[timeptr->tm_mon] : "???"),
 		timeptr->tm_mday, timeptr->tm_hour,
 		timeptr->tm_min, timeptr->tm_sec);
 	trail = timeptr->tm_year % DIVISOR + TM_YEAR_BASE % DIVISOR;
 	lead = timeptr->tm_year / DIVISOR + TM_YEAR_BASE / DIVISOR +
 		trail / DIVISOR;
 	trail %= DIVISOR;
 	if (trail < 0 && lead > 0) {
 		trail += DIVISOR;
 		--lead;
 	} else if (lead < 0 && trail > 0) {
 		trail -= DIVISOR;
 		++lead;
 	}
 	if (lead == 0)
 		printf("%d", trail);
 	else	printf("%d%d", lead, ((trail < 0) ? -trail : trail));
 }
diff --git a/contrib/tzcode/zic.8 b/contrib/tzcode/zic.8
index 37d9a3abd418..d6ded3563ee1 100644
--- a/contrib/tzcode/zic.8
+++ b/contrib/tzcode/zic.8
@@ -1,858 +1,859 @@
 .\" This file is in the public domain, so clarified as of
 .\" 2009-05-17 by Arthur David Olson.
-.\"
-.\" $FreeBSD$
-.\"
 .Dd January 21, 2023
 .Dt ZIC 8
 .Os
 .Sh NAME
 .Nm zic
 .Nd timezone compiler
 .Sh SYNOPSIS
 .Nm
 .Op Fl -help
 .Op Fl -version
 .Op Fl Dsv
 .Op Fl b Ar slim | fat
 .Op Fl d Ar directory
 .Op Fl g Ar gid
 .Op Fl l Ar localtime
 .Op Fl L Ar leapseconds
 .Op Fl m Ar mode
 .Op Fl p Ar posixrules
 .Oo
 .Fl r
 .Op @ Ns Ar lo Ns
 .Op /@ Ns Ar hi
 .Oc
 .Op Fl R @ Ns Ar hi
 .Op Fl t Ar localtime-link
 .Op Fl u Ar uid
 .Op Ar filename ...
 .Sh DESCRIPTION
 The
 .Nm
 program reads text from the file(s) named on the command line
 and creates the timezone information format (TZif) files
 specified in this input.
 If a
 .Ar filename
 is
 .Dq "-" ,
 standard input is read.
 .Pp
 The following options are available:
 .Bl -tag -width indent
 .It Fl -version
 Output version information and exit.
 .It Fl -help
 Output short usage message and exit.
 .It Fl b Ar bloat
 Output backward-compatibility data as specified by
 .Ar bloat .
 If
 .Ar bloat
 is
 .Cm fat ,
 generate additional data entries that work around potential bugs or
 incompatibilities in older software, such as software that mishandles
 the 64-bit generated data.
 If
 .Ar bloat
 is
 .Cm slim ,
 keep the output files small; this can help check for the bugs
 and incompatibilities.
 The default is
 .Cm slim ,
 as software that mishandles 64-bit data typically
 mishandles timestamps after the year 2038 anyway.
 Also see the
 .Fl r
 option for another way to alter output size.
 .It Fl D
 Do not create directories.
 .It Fl d Ar directory
 Create time conversion information files in the named directory rather than
 in the standard directory named below.
 .It Fl l Ar timezone
 Use
 .Ar timezone
 as local time.
 The
 .Nm
 utility
 will act as if the input contained a link line of the form
 .Bd -literal -offset indent
 Link	timezone		localtime
 .Ed
 .Pp
 If
 .Ar timezone
 is
 .Ql - ,
 any already-existing link is removed.
 .It Fl L Ar filename
 Read leap second information from the file with the given name.
 If this option is not used,
 no leap second information appears in output files.
 .It Fl p Ar timezone
 Use
 .Ar timezone 's
 rules when handling nonstandard
 TZ strings like
 .Dq "EET\-2EEST"
 that lack transition rules.
 The
 .Nm
 utility
 will act as if the input contained a link line of the form
 .Bd -literal -offset indent
 Link	\fItimezone\fP		posixrules
 .Ed
 .Pp
-This feature is obsolete and poorly supported.
+Unless
+.Ar timezone
+is
+.Dq "\*-" ,
+this option is obsolete and poorly supported.
 Among other things it should not be used for timestamps after the year 2037,
 and it should not be combined with
 .Fl b Cm slim
 if
 .Ar timezone 's
 transitions are at standard time or Universal Time (UT) instead of local time.
 .Pp
 If
 .Ar timezone
 is
 .Ql - ,
 any already-existing link is removed.
 .It Fl r Oo @ Ns Ar lo Oc Ns Oo /@ Ns Ar hi Oc
 Limit the applicability of output files
 to timestamps in the range from
 .Ar lo
 (inclusive) to
 .Ar hi
 (exclusive), where
 .Ar lo
 and
 .Ar hi
-are possibly-signed decimal counts of seconds since the Epoch
+are possibly signed decimal counts of seconds since the Epoch
 (1970-01-01 00:00:00 UTC).
 Omitted counts default to extreme values.
 The output files use UT offset 0 and abbreviation
 .Dq "\-00"
 in place of the omitted timestamp data.
 For example,
 .Fl r @0
 omits data intended for negative timestamps (i.e., before the Epoch), and
 .Fl r @0/@2147483648
 outputs data intended only for nonnegative timestamps that fit into
 31-bit signed integers.
 Although this option typically reduces the output file's size,
 the size can increase due to the need to represent the timestamp range
 boundaries, particularly if
 .Ar hi
 causes a TZif file to contain explicit entries for
 .Em pre-
 .Ar hi
 transitions rather than concisely representing them
 with an extended POSIX TZ string.
 Also see the
 .Fl b Cm slim
 option for another way to shrink output size.
 .It Fl R @ Ns Ar hi
 Generate redundant trailing explicit transitions for timestamps
 that occur less than
 .Ar hi
 seconds since the Epoch, even though the transitions could be
 more concisely represented via the extended POSIX TZ string.
 This option does not affect the represented timestamps.
 Although it accommodates nonstandard TZif readers
 that ignore the extended POSIX TZ string,
 it increases the size of the altered output files.
 .It Fl t Ar file
 When creating local time information, put the configuration link in
 the named file rather than in the standard location.
 .It Fl v
 Be more verbose, and complain about the following situations:
 .Bl -bullet
 .It
 The input specifies a link to a link,
 something not supported by some older parsers, including
 .Nm
 itself through release 2022e.
 .It
 A year that appears in a data file is outside the range
 of representable years.
 .It
 A time of 24:00 or more appears in the input.
 Pre-1998 versions of
 .Nm
 prohibit 24:00, and pre-2007 versions prohibit times greater than 24:00.
 .It
 A rule goes past the start or end of the month.
 Pre-2004 versions of
 .Nm
 prohibit this.
 .It
 A time zone abbreviation uses a
 .Ql %z
 format.
 Pre-2015 versions of
 .Nm
 do not support this.
 .It
 A timestamp contains fractional seconds.
 Pre-2018 versions of
 .Nm
 do not support this.
 .It
 The input contains abbreviations that are mishandled by pre-2018 versions of
 .Nm
 due to a longstanding coding bug.
 These abbreviations include
 .Dq L
 for
 .Dq Link ,
 .Dq mi
 for
 .Dq min ,
 .Dq Sa
 for
 .Dq Sat ,
 and
 .Dq Su
 for
 .Dq Sun .
 .It
 The output file does not contain all the information about the
 long-term future of a timezone, because the future cannot be summarized as
 an extended POSIX TZ string.
-For example, as of 2019 this problem
-occurs for Iran's daylight-saving rules for the predicted future, as
-these rules are based on the Iranian calendar, which cannot be
-represented.
+For example, as of 2023 this problem
+occurs for Morocco's daylight-saving rules, as these rules are based
+on predictions for when Ramadan will be observed, something that
+an extended POSIX TZ string cannot represent.
 .It
 The output contains data that may not be handled properly by client
 code designed for older
 .Nm
 output formats.
 These compatibility issues affect only timestamps
 before 1970 or after the start of 2038.
 .It
 The output contains a truncated leap second table,
 which can cause some older TZif readers to misbehave.
 This can occur if the
 .Fl L
 option is used, and either an Expires line is present or
 the
 .Fl r
 option is also used.
 .It
 The output file contains more than 1200 transitions,
 which may be mishandled by some clients.
 The current reference client supports at most 2000 transitions;
 pre-2014 versions of the reference client support at most 1200
 transitions.
 .It
 A time zone abbreviation has fewer than 3 or more than 6 characters.
 POSIX requires at least 3, and requires implementations to support
 at least 6.
 .It
 An output file name contains a byte that is not an ASCII letter,
 .Dq "\-" ,
 .Dq "/" ,
 or
 .Dq "_" ;
 or it contains a file name component that contains more than 14 bytes
 or that starts with
 .Dq "\-" .
 .El
 .El
 .RE
 .Sh FILES
 Input files use the format described in this section; output files use
 .Xr tzfile 5
 format.
 .Pp
 Input files should be text files, that is, they should be a series of
 zero or more lines, each ending in a newline byte and containing at
 most 2048 bytes counting the newline, and without any NUL bytes.
 The input text's encoding
 is typically UTF-8 or ASCII; it should have a unibyte representation
 for the POSIX Portable Character Set (PPCS)
 \*
 and the encoding's non-unibyte characters should consist entirely of
 non-PPCS bytes.
 Non-PPCS characters typically occur only in comments:
 although output file names and time zone abbreviations can contain
 nearly any character, other software will work better if these are
 limited to the restricted syntax described under the
 .Fl v
 option.
 .Pp
 Input lines are made up of fields.
 Fields are separated from one another by one or more white space characters.
 The white space characters are space, form feed, carriage return, newline,
 tab, and vertical tab.
 Leading and trailing white space on input lines is ignored.
 An unquoted sharp character (\(sh) in the input introduces a comment which extends
 to the end of the line the sharp character appears on.
 White space characters and sharp characters may be enclosed in double quotes
 (\(dq) if they're to be used as part of a field.
 Any line that is blank (after comment stripping) is ignored.
 Nonblank lines are expected to be of one of three types:
 rule lines, zone lines, and link lines.
 .Pp
 Names must be in English and are case insensitive.
 They appear in several contexts, and include month and weekday names
 and keywords such as
 .Dq "maximum" ,
 .Dq "only" ,
 .Dq "Rolling" ,
 and
 .Dq "Zone" .
 A name can be abbreviated by omitting all but an initial prefix; any
 abbreviation must be unambiguous in context.
 .Pp
 A rule line has the form
 .Bd -literal -offset indent
 Rule	NAME	FROM	TO	\-	IN	ON	AT	SAVE	LETTER/S
 .Ed
 .Pp
 For example:
 .Bd -literal -offset indent
 Rule	US	1967	1973	\-	Apr	lastSun	2:00w	1:00d	D
 .Ed
 .Pp
 The fields that make up a rule line are:
 .Bl -tag -width "LETTER/S"
 .It NAME
 Gives the name of the rule set that contains this line.
 The name must start with a character that is neither
 an ASCII digit nor
 .Dq \-
 nor
 .Dq + .
 To allow for future extensions,
 an unquoted name should not contain characters from the set
 .Dq Ql "!$%&'()*,/:;<=>?@[\]^`{|}~" .
 .It FROM
 Gives the first year in which the rule applies.
 Any signed integer year can be supplied; the proleptic Gregorian calendar
 is assumed, with year 0 preceding year 1.
 The word
 .Cm minimum
 (or an abbreviation) means the indefinite past.
 The word
 .Cm maximum
 (or an abbreviation) means the indefinite future.
 Rules can describe times that are not representable as time values,
 with the unrepresentable times ignored; this allows rules to be portable
 among hosts with differing time value types.
 .It TO
 Gives the final year in which the rule applies.
 In addition to
 .Cm minimum
 and
 .Cm maximum
 (as above),
 the word
 .Cm only
 (or an abbreviation)
 may be used to repeat the value of the
 .Ar FROM
 field.
 .It \-
 Is a reserved field and should always contain
 .Ql \-
 for compatibility with older versions of
 .Nm .
 It was previously known as the
 .Ar TYPE
 field, which could contain values to allow a
 separate script to further restrict in which
 .Dq types
 of years the rule would apply.
 .It IN
 Names the month in which the rule takes effect.
 Month names may be abbreviated.
 .It ON
 Gives the day on which the rule takes effect.
 Recognized forms include:
 .Bl -tag -compact -width "Sun<=25"
 .It 5
 the fifth of the month
 .It lastSun
 the last Sunday in the month
 .It lastMon
 the last Monday in the month
 .It Sun>=8
 first Sunday on or after the eighth
 .It Sun<=25
 last Sunday on or before the 25th
 .El
 .Pp
 A weekday name (e.g.,
 .Ql "Sunday" )
 or a weekday name preceded by
 .Dq "last"
 (e.g.,
 .Ql "lastSunday" )
 may be abbreviated or spelled out in full.
 There must be no white space characters within the
 .Ar ON
 field.
 The
 .Dq <=
 and
 .Dq >=
 constructs can result in a day in the neighboring month;
 for example, the IN-ON combination
 .Dq "Oct Sun>=31"
 stands for the first Sunday on or after October 31,
 even if that Sunday occurs in November.
 .It AT
 Gives the time of day at which the rule takes effect,
 relative to 00:00, the start of a calendar day.
 Recognized forms include:
 .Bl -tag -compact -width "00:19:32.13"
 .It 2
 time in hours
 .It 2:00
 time in hours and minutes
 .It 01:28:14
 time in hours, minutes, and seconds
 .It 00:19:32.13
 time with fractional seconds
 .It 12:00
 midday, 12 hours after 00:00
 .It 15:00
 3 PM, 15 hours after 00:00
 .It 24:00
 end of day, 24 hours after 00:00
 .It 260:00
 260 hours after 00:00
 .It \-2:30
 2.5 hours before 00:00
 .It \-
 equivalent to 0
 .El
 .Pp
 Although
 .Nm
 rounds times to the nearest integer second
 (breaking ties to the even integer), the fractions may be useful
 to other applications requiring greater precision.
 The source format does not specify any maximum precision.
 Any of these forms may be followed by the letter
 .Ql w
 if the given time is local or
 .Dq "wall clock"
 time,
 .Ql s
 if the given time is standard time without any adjustment for daylight saving,
 or
 .Ql u
 (or
 .Ql g
 or
 .Ql z )
 if the given time is universal time;
 in the absence of an indicator,
 local (wall clock) time is assumed.
 These forms ignore leap seconds; for example,
 if a leap second occurs at 00:59:60 local time,
 .Ql "1:00"
 stands for 3601 seconds after local midnight instead of the usual 3600 seconds.
 The intent is that a rule line describes the instants when a
 clock/calendar set to the type of time specified in the
 .Ar AT
 field would show the specified date and time of day.
 .It SAVE
 Gives the amount of time to be added to local standard time when the rule is in
 effect, and whether the resulting time is standard or daylight saving.
 This field has the same format as the
 .Ar AT
 field
 except with a different set of suffix letters:
 .Ql s
 for standard time and
 .Ql d
 for daylight saving time.
 The suffix letter is typically omitted, and defaults to
 .Ql s
 if the offset is zero and to
 .Ql d
 otherwise.
 Negative offsets are allowed; in Ireland, for example, daylight saving
 time is observed in winter and has a negative offset relative to
 Irish Standard Time.
 The offset is merely added to standard time; for example,
 .Nm
 does not distinguish a 10:30 standard time plus an 0:30
 .Ar SAVE
 from a 10:00 standard time plus a 1:00
 .Ar SAVE .
 .It LETTER/S
 Gives the
 .Dq "variable part"
 (for example, the
 .Dq "S"
 or
 .Dq "D"
 in
 .Dq "EST"
 or
 .Dq "EDT" )
 of time zone abbreviations to be used when this rule is in effect.
 If this field is
 .Ql \- ,
 the variable part is null.
 .El
 .Pp
 A zone line has the form
 .Bd -literal -offset indent
 Zone	NAME	STDOFF	RULES	FORMAT	[UNTIL]
 .Ed
 .Pp
 For example:
 .Bd -literal -offset indent
 Zone	Asia/Amman	2:00	Jordan	EE%sT	2017 Oct 27 01:00
 .Ed
 .Pp
 The fields that make up a zone line are:
 .Bl -tag -width "STDOFF"
 .It NAME
 The name of the timezone.
 This is the name used in creating the time conversion information file for the
 timezone.
 It should not contain a file name component
 .Dq ".\&"
 or
 .Dq ".." ;
 a file name component is a maximal substring that does not contain
 .Dq "/" .
 .It STDOFF
 The amount of time to add to UT to get standard time,
 without any adjustment for daylight saving.
 This field has the same format as the
 .Ar AT
 and
 .Ar SAVE
 fields of rule lines, except without suffix letters;
 begin the field with a minus sign if time must be subtracted from UT.
 .It RULES
 The name of the rules that apply in the timezone or,
 alternatively, a field in the same format as a rule-line SAVE column,
 giving the amount of time to be added to local standard time
 and whether the resulting time is standard or daylight saving.
 If this field is
 .Ql \-
 then standard time always applies.
 When an amount of time is given, only the sum of standard time and
 this amount matters.
 .It FORMAT
 The format for time zone abbreviations.
 The pair of characters
 .Ql %s
 is used to show where the
 .Dq "variable part"
 of the time zone abbreviation goes.
 Alternatively, a format can use the pair of characters
 .Ql %z
 to stand for the UT offset in the form
 .Ar \(+- hh ,
 .Ar \(+- hhmm ,
 or
 .Ar \(+- hhmmss ,
 using the shortest form that does not lose information, where
 .Ar hh ,
 .Ar mm ,
 and
 .Ar ss
 are the hours, minutes, and seconds east (+) or west (\-) of UT.
 Alternatively,
 a slash (/)
 separates standard and daylight abbreviations.
 To conform to POSIX, a time zone abbreviation should contain only
 alphanumeric ASCII characters,
 .Ql "+"
 and
 .Ql "\-".
 By convention, the time zone abbreviation
 .Ql "\-00"
 is a placeholder that means local time is unspecified.
 .It UNTIL
 The time at which the UT offset or the rule(s) change for a location.
 It takes the form of one to four fields
 .Ar YEAR Op Ar MONTH Op Ar DAY Op Ar TIME .
 If this is specified,
 the time zone information is generated from the given UT offset
 and rule change until the time specified, which is interpreted using
 the rules in effect just before the transition.
 The month, day, and time of day have the same format as the
 .Ar IN ,
 .Ar ON ,
 and
 .Ar AT
 fields of a rule; trailing fields can be omitted, and default to the
 earliest possible value for the missing fields.
 .IP
 The next line must be a
 .Dq "continuation"
 line; this has the same form as a zone line except that the
 string
 .Dq "Zone"
 and the name are omitted, as the continuation line will
 place information starting at the time specified as the
 .Dq "until"
 information in the previous line in the file used by the previous line.
 Continuation lines may contain
 .Dq "until"
 information, just as zone lines do, indicating that the next line is a further
 continuation.
 .El
 .Pp
 If a zone changes at the same instant that a rule would otherwise take
 effect in the earlier zone or continuation line, the rule is ignored.
 A zone or continuation line
 .Ar L
 with a named rule set starts with standard time by default:
 that is, any of
 .Ar L 's
 timestamps preceding
 .Ar L 's
 earliest rule use the rule in effect after
 .Ar L 's
 first transition into standard time.
 In a single zone it is an error if two rules take effect at the same
 instant, or if two zone changes take effect at the same instant.
 .Pp
 If a continuation line subtracts
 .Ar N
 seconds from the UT offset after a transition that would be
 interpreted to be later if using the continuation line's UT offset and
 rules, the
 .Dq "until"
 time of the previous zone or continuation line is interpreted
 according to the continuation line's UT offset and rules, and any rule
 that would otherwise take effect in the next
 .Ar N
 seconds is instead assumed to take effect simultaneously.
 For example:
 .Bd -literal -offset indent
 # Rule	NAME	FROM	TO	\*-	IN	ON	AT	SAVE	LETTER/S
 Rule	US	1967	2006	-	Oct	lastSun	2:00	0	S
 Rule	US	1967	1973	-	Apr	lastSun	2:00	1:00	D
 
 # Zone\0\0NAME	STDOFF	RULES	FORMAT	[UNTIL]
 Zone\0\0America/Menominee	\*-5:00	\*-	EST	1973 Apr 29 2:00
 	\*-6:00	US	C%sT
 .Ed
 Here, an incorrect reading would be there were two clock changes on 1973-04-29,
 the first from 02:00 EST (\-05) to 01:00 CST (\-06),
 and the second an hour later from 02:00 CST (\-06) to 03:00 CDT (\-05).
 However,
 .Nm
 interprets this more sensibly as a single transition from 02:00 CST (\-05) to
 02:00 CDT (\-05).
 .Pp
 A link line has the form
 .Bd -literal -offset indent
 Link	TARGET	LINK-NAME
 .Ed
 .Pp
 For example:
 .Bd -literal -offset indent
 Link	Europe/Istanbul	Asia/Istanbul
 .Ed
 .Pp
 The
 .Ar TARGET
 field should appear as the
 .Ar NAME
 field in some zone line or as the
 .Ar LINK-NAME
 field in some link line.
 The
 .Ar LINK-NAME
 field is used as an alternative name for that zone;
 it has the same syntax as a zone line's
 .Ar NAME
 field.
 Links can chain together, although the behavior is unspecified if a
 chain of one or more links does not terminate in a Zone name.
 A link line can appear before the line that defines the link target.
 For example:
 .Bd -literal -offset indent
 Link	Greenwich	G_M_T
 Link	Etc/GMT	Greenwich
 Zone	Etc/GMT\0\00\0\0\-\0\0GMT
 .Ed
 .Pp
 The two links are chained together, and G_M_T, Greenwich, and Etc/GMT
 all name the same zone.
 .Pp
 Except for continuation lines,
 lines may appear in any order in the input.
 However, the behavior is unspecified if multiple zone or link lines
 define the same name.
 .Pp
 The file that describes leap seconds can have leap lines and an
 expiration line.
 Leap lines have the following form:
 .Bd -literal -offset indent
 Leap	YEAR	MONTH	DAY	HH:MM:SS	CORR	R/S
 .Ed
 .Pp
 For example:
 .Bd -literal -offset indent
 Leap	2016	Dec	31	23:59:60	+	S
 .Ed
 .Pp
 The
 .Ar YEAR ,
 .Ar MONTH ,
 .Ar DAY ,
 and
 .Ar HH:MM:SS
 fields tell when the leap second happened.
 The
 .Ar CORR
 field
 should be
 .Ql "+"
 if a second was added
 or
 .Ql "\-"
 if a second was skipped.
 The
 .Ar R/S
 field
 should be (an abbreviation of)
 .Dq "Stationary"
 if the leap second time given by the other fields should be interpreted as UTC
 or
 (an abbreviation of)
 .Dq "Rolling"
 if the leap second time given by the other fields should be interpreted as
 local (wall clock) time.
 .Pp
 Rolling leap seconds were implemented back when it was not
 clear whether common practice was rolling or stationary,
 with concerns that one would see
 Times Square ball drops where there'd be a
 .Dq "3... 2... 1... leap... Happy New Year"
 countdown, placing the leap second at
 midnight New York time rather than midnight UTC.
 However, this countdown style does not seem to have caught on,
 which means rolling leap seconds are not used in practice;
 also, they are not supported if the
 .Fl r
 option is used.
 .Pp
 The expiration line, if present, has the form:
 .Bd -literal -offset indent
 Expires	YEAR	MONTH	DAY	HH:MM:SS
 .Ed
 .Pp
 For example:
 .Bd -literal -offset indent
 Expires	2020	Dec	28	00:00:00
 .Ed
 .Pp
 The
 .Ar YEAR ,
 .Ar MONTH ,
 .Ar DAY ,
 and
 .Ar HH:MM:SS
 fields give the expiration timestamp in UTC for the leap second table.
 .Sh "EXTENDED EXAMPLE"
 Here is an extended example of
 .Nm
 input, intended to illustrate many of its features.
 .Bd -literal -offset indent
 # Rule	NAME	FROM	TO	\-	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	\-
 
 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	\-
 
 # Zone	NAME	STDOFF	RULES	FORMAT	[UNTIL]
 Zone	Europe/Zurich	0:34:08	\-	LMT	1853 Jul 16
 		0:29:45.50	\-	BMT	1894 Jun
 		1:00	Swiss	CE%sT	1981
 		1:00	EU	CE%sT
 
 Link	Europe/Zurich	Europe/Vaduz
 .Ed
 .Pp
 In this example, the EU rules are for the European Union
 and for its predecessor organization, the European Communities.
 The timezone is named Europe/Zurich and it has the alias Europe/Vaduz.
 This example says that Zurich was 34 minutes and 8
 seconds east of UT until 1853-07-16 at 00:00, when the legal offset
 was changed to
 7\(de26\(fm22.50\(sd,
 which works out to 0:29:45.50;
 .Nm
 treats this by rounding it to 0:29:46.
 After 1894-06-01 at 00:00 the UT offset became one hour
 and Swiss daylight saving rules (defined with lines beginning with
 .Dq "Rule Swiss")
 apply.
 From 1981 to the present, EU daylight saving rules have
 applied, and the UTC offset has remained at one hour.
 .Pp
 In 1941 and 1942, daylight saving time applied from the first Monday
 in May at 01:00 to the first Monday in October at 02:00.
 The pre-1981 EU daylight-saving rules have no effect
 here, but are included for completeness.
 Since 1981, daylight
 saving has begun on the last Sunday in March at 01:00 UTC.
 Until 1995 it ended the last Sunday in September at 01:00 UTC,
 but this changed to the last Sunday in October starting in 1996.
 .Pp
 For purposes of display,
 .Dq "LMT"
 and
 .Dq "BMT"
 were initially used, respectively.
 Since
 Swiss rules and later EU rules were applied, the time zone abbreviation
 has been CET for standard time and CEST for daylight saving
 time.
 .Sh FILES
 .Bl -tag -width "/usr/share/zoneinfo"
 .It Pa /etc/localtime
 Default local timezone file.
 .It Pa /usr/share/zoneinfo
 Default timezone information directory.
 .El
 .Sh NOTES
 For areas with more than two types of local time,
 you may need to use local standard time in the
 .Ar AT
 field of the earliest transition time's rule to ensure that
 the earliest transition time recorded in the compiled file is correct.
 .Pp
 If,
 for a particular timezone,
 a clock advance caused by the start of daylight saving
 coincides with and is equal to
 a clock retreat caused by a change in UT offset,
 .Nm
 produces a single transition to daylight saving at the new UT offset
 without any change in local (wall clock) time.
 To get separate transitions
 use multiple zone continuation lines
 specifying transition instants using universal time.
 .Sh SEE ALSO
 .Xr tzfile 5 ,
 .Xr zdump 8
diff --git a/contrib/tzcode/zic.c b/contrib/tzcode/zic.c
index c65282d46d27..55ce60315ffd 100644
--- a/contrib/tzcode/zic.c
+++ b/contrib/tzcode/zic.c
@@ -1,4049 +1,4050 @@
 /* Compile .zi time zone data into TZif binary files.  */
 
 /*
 ** This file is in the public domain, so clarified as of
 ** 2006-07-17 by Arthur David Olson.
 */
 
 /* Use the system 'time' function, instead of any private replacement.
    This avoids creating an unnecessary dependency on localtime.c.  */
 #undef EPOCH_LOCAL
 #undef EPOCH_OFFSET
 #undef RESERVE_STD_EXT_IDS
 #undef time_tz
 
 #include "version.h"
 #include "private.h"
 #include "tzfile.h"
 
 #include 
 #include 
 #include 
 #include 
 #include 
 
 typedef int_fast64_t	zic_t;
 static zic_t const
   ZIC_MIN = INT_FAST64_MIN,
   ZIC_MAX = INT_FAST64_MAX,
   ZIC32_MIN = -1 - (zic_t) 0x7fffffff,
   ZIC32_MAX = 0x7fffffff;
 #define SCNdZIC SCNdFAST64
 
 #ifndef ZIC_MAX_ABBR_LEN_WO_WARN
 # define ZIC_MAX_ABBR_LEN_WO_WARN 6
 #endif /* !defined ZIC_MAX_ABBR_LEN_WO_WARN */
 
 /* An upper bound on how much a format might grow due to concatenation.  */
 enum { FORMAT_LEN_GROWTH_BOUND = 5 };
 
 #ifdef HAVE_DIRECT_H
 # include 
 # include 
 # undef mkdir
 # define mkdir(name, mode) _mkdir(name)
 #endif
 
 #ifndef HAVE_GETRANDOM
 # ifdef __has_include
 #  if __has_include()
 #   include 
 #  endif
 # elif 2 < __GLIBC__ + (25 <= __GLIBC_MINOR__)
 #  include 
 # endif
 # define HAVE_GETRANDOM GRND_RANDOM
 #elif HAVE_GETRANDOM
 # include 
 #endif
 
 #if HAVE_SYS_STAT_H
 # include 
 #endif
 #ifdef S_IRUSR
 # define MKDIR_UMASK (S_IRUSR|S_IWUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH)
 #else
 # define MKDIR_UMASK 0755
 #endif
 
-/* The minimum alignment of a type, for pre-C23 platforms.  */
-#if __STDC_VERSION__ < 201112
+/* The minimum alignment of a type, for pre-C23 platforms.
+   The __SUNPRO_C test is because Oracle Developer Studio 12.6 lacks
+    even though __STDC_VERSION__ == 201112.  */
+#if __STDC_VERSION__ < 201112 || defined __SUNPRO_C
 # define alignof(type) offsetof(struct { char a; type b; }, b)
 #elif __STDC_VERSION__ < 202311
 # include 
 #endif
 
 /* The maximum length of a text line, including the trailing newline.  */
 #ifndef _POSIX2_LINE_MAX
 # define _POSIX2_LINE_MAX 2048
 #endif
 
 /* The type for line numbers.  Use PRIdMAX to format them; formerly
    there was also "#define PRIdLINENO PRIdMAX" and formats used
    PRIdLINENO, but xgettext cannot grok that.  */
 typedef intmax_t lineno;
 
 struct rule {
 	int		r_filenum;
 	lineno		r_linenum;
 	const char *	r_name;
 
 	zic_t		r_loyear;	/* for example, 1986 */
 	zic_t		r_hiyear;	/* for example, 1986 */
 	bool		r_lowasnum;
 	bool		r_hiwasnum;
 
 	int		r_month;	/* 0..11 */
 
 	int		r_dycode;	/* see below */
 	int		r_dayofmonth;
 	int		r_wday;
 
 	zic_t		r_tod;		/* time from midnight */
 	bool		r_todisstd;	/* is r_tod standard time? */
 	bool		r_todisut;	/* is r_tod UT? */
 	bool		r_isdst;	/* is this daylight saving time? */
 	zic_t		r_save;		/* offset from standard time */
 	const char *	r_abbrvar;	/* variable part of abbreviation */
 
 	bool		r_todo;		/* a rule to do (used in outzone) */
 	zic_t		r_temp;		/* used in outzone */
 };
 
 /*
 ** r_dycode	r_dayofmonth	r_wday
 */
 enum {
   DC_DOM,	/* 1..31 */	/* unused */
   DC_DOWGEQ,	/* 1..31 */	/* 0..6 (Sun..Sat) */
   DC_DOWLEQ	/* 1..31 */	/* 0..6 (Sun..Sat) */
 };
 
 struct zone {
 	int		z_filenum;
 	lineno		z_linenum;
 
 	const char *	z_name;
 	zic_t		z_stdoff;
 	char *		z_rule;
 	const char *	z_format;
 	char		z_format_specifier;
 
 	bool		z_isdst;
 	zic_t		z_save;
 
 	struct rule *	z_rules;
 	ptrdiff_t	z_nrules;
 
 	struct rule	z_untilrule;
 	zic_t		z_untiltime;
 };
 
 #if !HAVE_POSIX_DECLS
 extern int	getopt(int argc, char * const argv[],
 			const char * options);
 extern int	link(const char * target, const char * linkname);
 extern char *	optarg;
 extern int	optind;
 #endif
 
 #if ! HAVE_SYMLINK
 static ssize_t
 readlink(char const *restrict file, char *restrict buf, size_t size)
 {
   errno = ENOTSUP;
   return -1;
 }
 static int
 symlink(char const *target, char const *linkname)
 {
   errno = ENOTSUP;
   return -1;
 }
 #endif
 #ifndef AT_SYMLINK_FOLLOW
 # if HAVE_LINK
 #  define linkat(targetdir, target, linknamedir, linkname, flag) \
      (itssymlink(target) ? (errno = ENOTSUP, -1) : link(target, linkname))
 # else
 #  define linkat(targetdir, target, linknamedir, linkname, flag) \
      (errno = ENOTSUP, -1)
 # endif
 #endif
 
 static void	addtt(zic_t starttime, int type);
 static int	addtype(zic_t, char const *, bool, bool, bool);
 static void	leapadd(zic_t, int, int);
 static void	adjleap(void);
 static void	associate(void);
 static void	dolink(const char *, const char *, bool);
 static int	getfields(char *, char **, int);
 static zic_t	gethms(const char * string, const char * errstring);
 static zic_t	getsave(char *, bool *);
 static void	inexpires(char **, int);
 static void	infile(int, char const *);
 static void	inleap(char ** fields, int nfields);
 static void	inlink(char ** fields, int nfields);
 static void	inrule(char ** fields, int nfields);
 static bool	inzcont(char ** fields, int nfields);
 static bool	inzone(char ** fields, int nfields);
 static bool	inzsub(char **, int, bool);
 static bool	itssymlink(char const *);
 static bool	is_alpha(char a);
 static char	lowerit(char);
 static void	mkdirs(char const *, bool);
 static void	newabbr(const char * abbr);
 static zic_t	oadd(zic_t t1, zic_t t2);
 static void	outzone(const struct zone * zp, ptrdiff_t ntzones);
 static zic_t	rpytime(const struct rule * rp, zic_t wantedy);
 static bool	rulesub(struct rule * rp,
 			const char * loyearp, const char * hiyearp,
 			const char * typep, const char * monthp,
 			const char * dayp, const char * timep);
 static void	setgroup(gid_t *flag, const char *name);
 static void	setuser(uid_t *flag, const char *name);
 static zic_t	tadd(zic_t t1, zic_t t2);
 
 /* Bound on length of what %z can expand to.  */
 enum { PERCENT_Z_LEN_BOUND = sizeof "+995959" - 1 };
 
 static int		charcnt;
 static bool		errors;
 static bool		warnings;
 static int		filenum;
 static int		leapcnt;
 static bool		leapseen;
 static zic_t		leapminyear;
 static zic_t		leapmaxyear;
 static lineno		linenum;
 static size_t		max_abbrvar_len = PERCENT_Z_LEN_BOUND;
 static int		max_format_len;
 static zic_t		max_year;
 static zic_t		min_year;
 static bool		noise;
 static int		rfilenum;
 static lineno		rlinenum;
 static const char *	progname;
 static char const *	leapsec;
 static char *const *	main_argv;
 static ptrdiff_t	timecnt;
 static ptrdiff_t	timecnt_alloc;
 static int		typecnt;
 static int		unspecifiedtype;
 
 /*
 ** Line codes.
 */
 
 enum {
   LC_RULE,
   LC_ZONE,
   LC_LINK,
   LC_LEAP,
   LC_EXPIRES
 };
 
 /*
 ** Which fields are which on a Zone line.
 */
 
 enum {
   ZF_NAME = 1,
   ZF_STDOFF,
   ZF_RULE,
   ZF_FORMAT,
   ZF_TILYEAR,
   ZF_TILMONTH,
   ZF_TILDAY,
   ZF_TILTIME,
   ZONE_MAXFIELDS,
   ZONE_MINFIELDS = ZF_TILYEAR
 };
 
 /*
 ** Which fields are which on a Zone continuation line.
 */
 
 enum {
   ZFC_STDOFF,
   ZFC_RULE,
   ZFC_FORMAT,
   ZFC_TILYEAR,
   ZFC_TILMONTH,
   ZFC_TILDAY,
   ZFC_TILTIME,
   ZONEC_MAXFIELDS,
   ZONEC_MINFIELDS = ZFC_TILYEAR
 };
 
 /*
 ** Which files are which on a Rule line.
 */
 
 enum {
   RF_NAME = 1,
   RF_LOYEAR,
   RF_HIYEAR,
   RF_COMMAND,
   RF_MONTH,
   RF_DAY,
   RF_TOD,
   RF_SAVE,
   RF_ABBRVAR,
   RULE_FIELDS
 };
 
 /*
 ** Which fields are which on a Link line.
 */
 
 enum {
   LF_TARGET = 1,
   LF_LINKNAME,
   LINK_FIELDS
 };
 
 /*
 ** Which fields are which on a Leap line.
 */
 
 enum {
   LP_YEAR = 1,
   LP_MONTH,
   LP_DAY,
   LP_TIME,
   LP_CORR,
   LP_ROLL,
   LEAP_FIELDS,
 
   /* Expires lines are like Leap lines, except without CORR and ROLL fields.  */
   EXPIRES_FIELDS = LP_TIME + 1
 };
 
 /* The maximum number of fields on any of the above lines.
    (The "+"s pacify gcc -Wenum-compare.)  */
 enum {
   MAX_FIELDS = max(max(+RULE_FIELDS, +LINK_FIELDS),
 		   max(+LEAP_FIELDS, +EXPIRES_FIELDS))
 };
 
 /*
 ** Year synonyms.
 */
 
 enum {
   YR_MINIMUM,
   YR_MAXIMUM,
   YR_ONLY
 };
 
 static struct rule *	rules;
 static ptrdiff_t	nrules;	/* number of rules */
 static ptrdiff_t	nrules_alloc;
 
 static struct zone *	zones;
 static ptrdiff_t	nzones;	/* number of zones */
 static ptrdiff_t	nzones_alloc;
 
 struct link {
 	int		l_filenum;
 	lineno		l_linenum;
 	const char *	l_target;
 	const char *	l_linkname;
 };
 
 static struct link *	links;
 static ptrdiff_t	nlinks;
 static ptrdiff_t	nlinks_alloc;
 
 struct lookup {
 	const char *	l_word;
 	const int	l_value;
 };
 
 static struct lookup const *	byword(const char * string,
 					const struct lookup * lp);
 
 static struct lookup const zi_line_codes[] = {
 	{ "Rule",	LC_RULE },
 	{ "Zone",	LC_ZONE },
 	{ "Link",	LC_LINK },
 	{ NULL,		0 }
 };
 static struct lookup const leap_line_codes[] = {
 	{ "Leap",	LC_LEAP },
 	{ "Expires",	LC_EXPIRES },
 	{ NULL,		0}
 };
 
 static struct lookup const	mon_names[] = {
 	{ "January",	TM_JANUARY },
 	{ "February",	TM_FEBRUARY },
 	{ "March",	TM_MARCH },
 	{ "April",	TM_APRIL },
 	{ "May",	TM_MAY },
 	{ "June",	TM_JUNE },
 	{ "July",	TM_JULY },
 	{ "August",	TM_AUGUST },
 	{ "September",	TM_SEPTEMBER },
 	{ "October",	TM_OCTOBER },
 	{ "November",	TM_NOVEMBER },
 	{ "December",	TM_DECEMBER },
 	{ NULL,		0 }
 };
 
 static struct lookup const	wday_names[] = {
 	{ "Sunday",	TM_SUNDAY },
 	{ "Monday",	TM_MONDAY },
 	{ "Tuesday",	TM_TUESDAY },
 	{ "Wednesday",	TM_WEDNESDAY },
 	{ "Thursday",	TM_THURSDAY },
 	{ "Friday",	TM_FRIDAY },
 	{ "Saturday",	TM_SATURDAY },
 	{ NULL,		0 }
 };
 
 static struct lookup const	lasts[] = {
 	{ "last-Sunday",	TM_SUNDAY },
 	{ "last-Monday",	TM_MONDAY },
 	{ "last-Tuesday",	TM_TUESDAY },
 	{ "last-Wednesday",	TM_WEDNESDAY },
 	{ "last-Thursday",	TM_THURSDAY },
 	{ "last-Friday",	TM_FRIDAY },
 	{ "last-Saturday",	TM_SATURDAY },
 	{ NULL,			0 }
 };
 
 static struct lookup const	begin_years[] = {
 	{ "minimum",	YR_MINIMUM },
 	{ "maximum",	YR_MAXIMUM },
 	{ NULL,		0 }
 };
 
 static struct lookup const	end_years[] = {
 	{ "minimum",	YR_MINIMUM },
 	{ "maximum",	YR_MAXIMUM },
 	{ "only",	YR_ONLY },
 	{ NULL,		0 }
 };
 
 static struct lookup const	leap_types[] = {
 	{ "Rolling",	true },
 	{ "Stationary",	false },
 	{ NULL,		0 }
 };
 
 static const int	len_months[2][MONSPERYEAR] = {
 	{ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
 	{ 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
 };
 
 static const int	len_years[2] = {
 	DAYSPERNYEAR, DAYSPERLYEAR
 };
 
 static struct attype {
 	zic_t		at;
 	bool		dontmerge;
 	unsigned char	type;
 } *			attypes;
 static zic_t		utoffs[TZ_MAX_TYPES];
 static char		isdsts[TZ_MAX_TYPES];
 static unsigned char	desigidx[TZ_MAX_TYPES];
 static bool		ttisstds[TZ_MAX_TYPES];
 static bool		ttisuts[TZ_MAX_TYPES];
 static char		chars[TZ_MAX_CHARS];
 static zic_t		trans[TZ_MAX_LEAPS];
 static zic_t		corr[TZ_MAX_LEAPS];
 static char		roll[TZ_MAX_LEAPS];
 
 /*
 ** Memory allocation.
 */
 
-static ATTRIBUTE_NORETURN void
+ATTRIBUTE_NORETURN static void
 memory_exhausted(const char *msg)
 {
 	fprintf(stderr, _("%s: Memory exhausted: %s\n"), progname, msg);
 	exit(EXIT_FAILURE);
 }
 
-static ATTRIBUTE_NORETURN void
+ATTRIBUTE_NORETURN static void
 size_overflow(void)
 {
   memory_exhausted(_("size overflow"));
 }
 
-static ATTRIBUTE_REPRODUCIBLE size_t
+ATTRIBUTE_REPRODUCIBLE static ptrdiff_t
 size_sum(size_t a, size_t b)
 {
 #ifdef ckd_add
-  size_t sum;
-  if (!ckd_add(&sum, a, b))
+  ptrdiff_t sum;
+  if (!ckd_add(&sum, a, b) && sum <= INDEX_MAX)
     return sum;
 #else
-  if (b <= SIZE_MAX - a)
+  if (a <= INDEX_MAX && b <= INDEX_MAX - a)
     return a + b;
 #endif
   size_overflow();
 }
 
-static ATTRIBUTE_REPRODUCIBLE size_t
-size_product(size_t nitems, size_t itemsize)
+ATTRIBUTE_REPRODUCIBLE static ptrdiff_t
+size_product(ptrdiff_t nitems, ptrdiff_t itemsize)
 {
 #ifdef ckd_mul
-  size_t product;
-  if (!ckd_mul(&product, nitems, itemsize))
+  ptrdiff_t product;
+  if (!ckd_mul(&product, nitems, itemsize) && product <= INDEX_MAX)
     return product;
 #else
-  if (nitems <= SIZE_MAX / itemsize)
+  ptrdiff_t nitems_max = INDEX_MAX / itemsize;
+  if (nitems <= nitems_max)
     return nitems * itemsize;
 #endif
   size_overflow();
 }
 
-static ATTRIBUTE_REPRODUCIBLE size_t
-align_to(size_t size, size_t alignment)
+ATTRIBUTE_REPRODUCIBLE static ptrdiff_t
+align_to(ptrdiff_t size, ptrdiff_t alignment)
 {
   size_t lo_bits = alignment - 1, sum = size_sum(size, lo_bits);
   return sum & ~lo_bits;
 }
 
 #if !HAVE_STRDUP
 static char *
 strdup(char const *str)
 {
   char *result = malloc(strlen(str) + 1);
   return result ? strcpy(result, str) : result;
 }
 #endif
 
 static void *
 memcheck(void *ptr)
 {
 	if (ptr == NULL)
 	  memory_exhausted(strerror(HAVE_MALLOC_ERRNO ? errno : ENOMEM));
 	return ptr;
 }
 
-static void * ATTRIBUTE_MALLOC
+ATTRIBUTE_MALLOC static void *
 emalloc(size_t size)
 {
   return memcheck(malloc(size));
 }
 
 static void *
 erealloc(void *ptr, size_t size)
 {
   return memcheck(realloc(ptr, size));
 }
 
-static char * ATTRIBUTE_MALLOC
+ATTRIBUTE_MALLOC static char *
 estrdup(char const *str)
 {
   return memcheck(strdup(str));
 }
 
 static ptrdiff_t
 grow_nitems_alloc(ptrdiff_t *nitems_alloc, ptrdiff_t itemsize)
 {
   ptrdiff_t addend = (*nitems_alloc >> 1) + 1;
 #if defined ckd_add && defined ckd_mul
   ptrdiff_t product;
   if (!ckd_add(nitems_alloc, *nitems_alloc, addend)
-      && !ckd_mul(&product, *nitems_alloc, itemsize) /* && product <= SIZE_MAX */)
+      && !ckd_mul(&product, *nitems_alloc, itemsize) && product <= INDEX_MAX)
     return product;
 #else
-  ptrdiff_t amax = min(PTRDIFF_MAX, SIZE_MAX);
-  if (*nitems_alloc <= ((amax - 1) / 3 * 2) / itemsize) {
+  if (*nitems_alloc <= ((INDEX_MAX - 1) / 3 * 2) / itemsize) {
     *nitems_alloc += addend;
     return *nitems_alloc * itemsize;
   }
 #endif
   memory_exhausted(_("integer overflow"));
 }
 
 static void *
 growalloc(void *ptr, ptrdiff_t itemsize, ptrdiff_t nitems,
 	  ptrdiff_t *nitems_alloc)
 {
   return (nitems < *nitems_alloc
 	  ? ptr
 	  : erealloc(ptr, grow_nitems_alloc(nitems_alloc, itemsize)));
 }
 
 /*
 ** Error handling.
 */
 
 /* In most of the code, an input file name is represented by its index
    into the main argument vector, except that LEAPSEC_FILENUM stands
    for leapsec and COMMAND_LINE_FILENUM stands for the command line.  */
 enum { LEAPSEC_FILENUM = -2, COMMAND_LINE_FILENUM = -1 };
 
 /* Return the name of the Ith input file, for diagnostics.  */
 static char const *
 filename(int i)
 {
   if (i == COMMAND_LINE_FILENUM)
     return _("command line");
   else {
     char const *fname = i == LEAPSEC_FILENUM ? leapsec : main_argv[i];
     return strcmp(fname, "-") == 0 ? _("standard input") : fname;
   }
 }
 
 static void
 eats(int fnum, lineno num, int rfnum, lineno rnum)
 {
 	filenum = fnum;
 	linenum = num;
 	rfilenum = rfnum;
 	rlinenum = rnum;
 }
 
 static void
 eat(int fnum, lineno num)
 {
 	eats(fnum, num, 0, -1);
 }
 
-static void ATTRIBUTE_FORMAT((printf, 1, 0))
+ATTRIBUTE_FORMAT((printf, 1, 0)) static void
 verror(const char *const string, va_list args)
 {
 	/*
 	** Match the format of "cc" to allow sh users to
 	**	zic ... 2>&1 | error -t "*" -v
 	** on BSD systems.
 	*/
 	if (filenum)
 	  fprintf(stderr, _("\"%s\", line %"PRIdMAX": "),
 		  filename(filenum), linenum);
 	vfprintf(stderr, string, args);
 	if (rfilenum)
 		fprintf(stderr, _(" (rule from \"%s\", line %"PRIdMAX")"),
 			filename(rfilenum), rlinenum);
 	fprintf(stderr, "\n");
 }
 
-static void ATTRIBUTE_FORMAT((printf, 1, 2))
+ATTRIBUTE_FORMAT((printf, 1, 2)) static void
 error(const char *const string, ...)
 {
 	va_list args;
 	va_start(args, string);
 	verror(string, args);
 	va_end(args);
 	errors = true;
 }
 
-static void ATTRIBUTE_FORMAT((printf, 1, 2))
+ATTRIBUTE_FORMAT((printf, 1, 2)) static void
 warning(const char *const string, ...)
 {
 	va_list args;
 	fprintf(stderr, _("warning: "));
 	va_start(args, string);
 	verror(string, args);
 	va_end(args);
 	warnings = true;
 }
 
 /* Close STREAM.  If it had an I/O error, report it against DIR/NAME,
    remove TEMPNAME if nonnull, and then exit.  */
 static void
 close_file(FILE *stream, char const *dir, char const *name,
 	   char const *tempname)
 {
   char const *e = (ferror(stream) ? _("I/O error")
 		   : fclose(stream) != 0 ? strerror(errno) : NULL);
   if (e) {
     fprintf(stderr, "%s: %s%s%s%s%s\n", progname,
 	    dir ? dir : "", dir ? "/" : "",
 	    name ? name : "", name ? ": " : "",
 	    e);
     if (tempname)
       (void)remove(tempname);
     exit(EXIT_FAILURE);
   }
 }
 
-static ATTRIBUTE_NORETURN void
+ATTRIBUTE_NORETURN static void
 usage(FILE *stream, int status)
 {
   fprintf(stream,
 	  _("%s: usage is %s [ --version ] [ --help ] [ -v ] \\\n"
 	    "\t[ -b {slim|fat} ] [ -d directory ] [ -l localtime ]"
 	    " [ -L leapseconds ] \\\n"
 	    "\t[ -p posixrules ] [ -r '[@lo][/@hi]' ] [ -R '@hi' ] \\\n"
 	    "\t[ -t localtime-link ] [ -D ] [ -g gid ] [ -u uid ] \\\n"
 	    "\t[ filename ... ]\n\n"
 	    "Report bugs to %s.\n"),
 	  progname, progname, REPORT_BUGS_TO);
   if (status == EXIT_SUCCESS)
     close_file(stream, NULL, NULL, NULL);
   exit(status);
 }
 
 /* Change the working directory to DIR, possibly creating DIR and its
    ancestors.  After this is done, all files are accessed with names
    relative to DIR.  */
 static void
 change_directory(char const *dir)
 {
   if (chdir(dir) != 0) {
     int chdir_errno = errno;
     if (chdir_errno == ENOENT) {
       mkdirs(dir, false);
       chdir_errno = chdir(dir) == 0 ? 0 : errno;
     }
     if (chdir_errno != 0) {
       fprintf(stderr, _("%s: Can't chdir to %s: %s\n"),
 	      progname, dir, strerror(chdir_errno));
       exit(EXIT_FAILURE);
     }
   }
 }
 
 /* Compare the two links A and B, for a stable sort by link name.  */
 static int
 qsort_linkcmp(void const *a, void const *b)
 {
   struct link const *l = a;
   struct link const *m = b;
   int cmp = strcmp(l->l_linkname, m->l_linkname);
   if (cmp)
     return cmp;
 
   /* The link names are the same.  Make the sort stable by comparing
      file numbers (where subtraction cannot overflow) and possibly
      line numbers (where it can).  */
   cmp = l->l_filenum - m->l_filenum;
   if (cmp)
     return cmp;
   return (l->l_linenum > m->l_linenum) - (l->l_linenum < m->l_linenum);
 }
 
 /* Compare the string KEY to the link B, for bsearch.  */
 static int
 bsearch_linkcmp(void const *key, void const *b)
 {
   struct link const *m = b;
   return strcmp(key, m->l_linkname);
 }
 
 /* Make the links specified by the Link lines.  */
 static void
 make_links(void)
 {
   ptrdiff_t i, j, nalinks, pass_size;
   if (1 < nlinks)
     qsort(links, nlinks, sizeof *links, qsort_linkcmp);
 
   /* Ignore each link superseded by a later link with the same name.  */
   j = 0;
   for (i = 0; i < nlinks; i++) {
     while (i + 1 < nlinks
 	   && strcmp(links[i].l_linkname, links[i + 1].l_linkname) == 0)
       i++;
     links[j++] = links[i];
   }
   nlinks = pass_size = j;
 
   /* Walk through the link array making links.  However,
      if a link's target has not been made yet, append a copy to the
      end of the array.  The end of the array will gradually fill
      up with a small sorted subsequence of not-yet-made links.
      nalinks counts all the links in the array, including copies.
      When we reach the copied subsequence, it may still contain
      a link to a not-yet-made link, so the process repeats.
      At any given point in time, the link array consists of the
      following subregions, where 0 <= i <= j <= nalinks and
      0 <= nlinks <= nalinks:
 
        0 .. (i - 1):
 	 links that either have been made, or have been copied to a
 	 later point point in the array (this later point can be in
 	 any of the three subregions)
        i .. (j - 1):
 	 not-yet-made links for this pass
        j .. (nalinks - 1):
 	 not-yet-made links that this pass has skipped because
 	 they were links to not-yet-made links
 
      The first subregion might not be sorted if nlinks < i;
      the other two subregions are sorted.  This algorithm does
      not alter entries 0 .. (nlinks - 1), which remain sorted.
 
      If there are L links, this algorithm is O(C*L*log(L)) where
      C is the length of the longest link chain.  Usually C is
      short (e.g., 3) though its worst-case value is L.  */
 
   j = nalinks = nlinks;
 
   for (i = 0; i < nalinks; i++) {
     struct link *l;
 
     eat(links[i].l_filenum, links[i].l_linenum);
 
     /* If this pass examined all its links, start the next pass.  */
     if (i == j) {
       if (nalinks - i == pass_size) {
 	error(_("\"Link %s %s\" is part of a link cycle"),
 	      links[i].l_target, links[i].l_linkname);
 	break;
       }
       j = nalinks;
       pass_size = nalinks - i;
     }
 
     /* Diagnose self links, which the cycle detection algorithm would not
        otherwise catch.  */
     if (strcmp(links[i].l_target, links[i].l_linkname) == 0) {
       error(_("link %s targets itself"), links[i].l_target);
       continue;
     }
 
     /* Make this link unless its target has not been made yet.  */
     l = bsearch(links[i].l_target, &links[i + 1], j - (i + 1),
 		sizeof *links, bsearch_linkcmp);
     if (!l)
       l = bsearch(links[i].l_target, &links[j], nalinks - j,
 		  sizeof *links, bsearch_linkcmp);
     if (!l)
       dolink(links[i].l_target, links[i].l_linkname, false);
     else {
       /* The link target has not been made yet; copy the link to the end.  */
       links = growalloc(links, sizeof *links, nalinks, &nlinks_alloc);
       links[nalinks++] = links[i];
     }
 
     if (noise && i < nlinks) {
       if (l)
 	warning(_("link %s targeting link %s mishandled by pre-2023 zic"),
 		links[i].l_linkname, links[i].l_target);
       else if (bsearch(links[i].l_target, links, nlinks, sizeof *links,
 		       bsearch_linkcmp))
 	warning(_("link %s targeting link %s"),
 		links[i].l_linkname, links[i].l_target);
     }
   }
 }
 
 /* Simple signal handling: just set a flag that is checked
    periodically outside critical sections.  To set up the handler,
    prefer sigaction if available to close a signal race.  */
 
 static sig_atomic_t got_signal;
 
 static void
 signal_handler(int sig)
 {
 #ifndef SA_SIGINFO
   signal(sig, signal_handler);
 #endif
   got_signal = sig;
 }
 
 /* Arrange for SIGINT etc. to be caught by the handler.  */
 static void
 catch_signals(void)
 {
   static int const signals[] = {
 #ifdef SIGHUP
     SIGHUP,
 #endif
     SIGINT,
 #ifdef SIGPIPE
     SIGPIPE,
 #endif
     SIGTERM
   };
   size_t i;
   for (i = 0; i < sizeof signals / sizeof signals[0]; i++) {
 #ifdef SA_SIGINFO
     struct sigaction act0, act;
     act.sa_handler = signal_handler;
     sigemptyset(&act.sa_mask);
     act.sa_flags = 0;
     if (sigaction(signals[i], &act, &act0) == 0
 	&& ! (act0.sa_flags & SA_SIGINFO) && act0.sa_handler == SIG_IGN) {
       sigaction(signals[i], &act0, NULL);
       got_signal = 0;
     }
 #else
     if (signal(signals[i], signal_handler) == SIG_IGN) {
       signal(signals[i], SIG_IGN);
       got_signal = 0;
     }
 #endif
   }
 }
 
 /* If a signal has arrived, terminate zic with appropriate status.  */
 static void
 check_for_signal(void)
 {
   int sig = got_signal;
   if (sig) {
     signal(sig, SIG_DFL);
     raise(sig);
     abort(); /* A bug in 'raise'.  */
   }
 }
 
 enum { TIME_T_BITS_IN_FILE = 64 };
 
 /* The minimum and maximum values representable in a TZif file.  */
 static zic_t const min_time = MINVAL(zic_t, TIME_T_BITS_IN_FILE);
 static zic_t const max_time = MAXVAL(zic_t, TIME_T_BITS_IN_FILE);
 
 /* The minimum, and one less than the maximum, values specified by
    the -r option.  These default to MIN_TIME and MAX_TIME.  */
 static zic_t lo_time = MINVAL(zic_t, TIME_T_BITS_IN_FILE);
 static zic_t hi_time = MAXVAL(zic_t, TIME_T_BITS_IN_FILE);
 
 /* The time specified by the -R option, defaulting to MIN_TIME.  */
 static zic_t redundant_time = MINVAL(zic_t, TIME_T_BITS_IN_FILE);
 
 /* The time specified by an Expires line, or negative if no such line.  */
 static zic_t leapexpires = -1;
 
 /* Set the time range of the output to TIMERANGE.
    Return true if successful.  */
 static bool
 timerange_option(char *timerange)
 {
   intmax_t lo = min_time, hi = max_time;
   char *lo_end = timerange, *hi_end;
   if (*timerange == '@') {
     errno = 0;
     lo = strtoimax(timerange + 1, &lo_end, 10);
     if (lo_end == timerange + 1 || (lo == INTMAX_MAX && errno == ERANGE))
       return false;
   }
   hi_end = lo_end;
   if (lo_end[0] == '/' && lo_end[1] == '@') {
     errno = 0;
     hi = strtoimax(lo_end + 2, &hi_end, 10);
     if (hi_end == lo_end + 2 || hi == INTMAX_MIN)
       return false;
     hi -= ! (hi == INTMAX_MAX && errno == ERANGE);
   }
   if (*hi_end || hi < lo || max_time < lo || hi < min_time)
     return false;
   lo_time = max(lo, min_time);
   hi_time = min(hi, max_time);
   return true;
 }
 
 /* Generate redundant time stamps up to OPT.  Return true if successful.  */
 static bool
 redundant_time_option(char *opt)
 {
   if (*opt == '@') {
     intmax_t redundant;
     char *opt_end;
     redundant = strtoimax(opt + 1, &opt_end, 10);
     if (opt_end != opt + 1 && !*opt_end) {
       redundant_time = max(redundant_time, redundant);
       return true;
     }
   }
   return false;
 }
 
 static const char *	psxrules;
 static const char *	lcltime;
 static const char *	directory;
 static const char *	leapsec;
 static int		Dflag;
 static uid_t		uflag = (uid_t)-1;
 static gid_t		gflag = (gid_t)-1;
 static mode_t		mflag = (S_IRUSR | S_IRGRP | S_IROTH
 				 | S_IWUSR);
 static const char *	tzdefault;
 
 /* -1 if the TZif output file should be slim, 0 if default, 1 if the
    output should be fat for backward compatibility.  ZIC_BLOAT_DEFAULT
    determines the default.  */
 static int bloat;
 
 static bool
 want_bloat(void)
 {
   return 0 <= bloat;
 }
 
 #ifndef ZIC_BLOAT_DEFAULT
 # define ZIC_BLOAT_DEFAULT "slim"
 #endif
 
 int
 main(int argc, char **argv)
 {
 	register int c, k;
 	register ptrdiff_t i, j;
 	bool timerange_given = false;
 
 #ifdef S_IWGRP
 	umask(umask(S_IWGRP | S_IWOTH) | (S_IWGRP | S_IWOTH));
 #endif
 #if HAVE_GETTEXT
 	setlocale(LC_ALL, "");
 # ifdef TZ_DOMAINDIR
 	bindtextdomain(TZ_DOMAIN, TZ_DOMAINDIR);
 # endif /* defined TEXTDOMAINDIR */
 	textdomain(TZ_DOMAIN);
 #endif /* HAVE_GETTEXT */
 	main_argv = argv;
 	progname = /* argv[0] ? argv[0] : */ "zic";
 	if (TYPE_BIT(zic_t) < 64) {
 		fprintf(stderr, "%s: %s\n", progname,
 			_("wild compilation-time specification of zic_t"));
 		return EXIT_FAILURE;
 	}
 	for (k = 1; k < argc; k++)
 		if (strcmp(argv[k], "--version") == 0) {
 			printf("zic %s%s\n", PKGVERSION, TZVERSION);
 			close_file(stdout, NULL, NULL, NULL);
 			return EXIT_SUCCESS;
 		} else if (strcmp(argv[k], "--help") == 0) {
 			usage(stdout, EXIT_SUCCESS);
 		}
 	while ((c = getopt(argc, argv, "Db:d:g:l:L:m:p:r:R:st:u:vy:")) != EOF
 	       && c != -1)
 		switch (c) {
 			default:
 				usage(stderr, EXIT_FAILURE);
 			case 'D':
 				Dflag = 1;
 				break;
 			case 'b':
 				if (strcmp(optarg, "slim") == 0) {
 				  if (0 < bloat)
 				    error(_("incompatible -b options"));
 				  bloat = -1;
 				} else if (strcmp(optarg, "fat") == 0) {
 				  if (bloat < 0)
 				    error(_("incompatible -b options"));
 				  bloat = 1;
 				} else
 				  error(_("invalid option: -b '%s'"), optarg);
 				break;
 			case 'd':
 				if (directory == NULL)
 					directory = optarg;
 				else {
 					fprintf(stderr,
 _("%s: More than one -d option specified\n"),
 						progname);
 					return EXIT_FAILURE;
 				}
 				break;
 			case 'g':
 				setgroup(&gflag, optarg);
 				break;
 			case 'l':
 				if (lcltime == NULL)
 					lcltime = optarg;
 				else {
 					fprintf(stderr,
 _("%s: More than one -l option specified\n"),
 						progname);
 					return EXIT_FAILURE;
 				}
 				break;
 			case 'm':
 			{
 				void *set = setmode(optarg);
 				if (set == NULL) {
 					fprintf(stderr,
 _("invalid file mode"));
 					return EXIT_FAILURE;
 				}
 				mflag = getmode(set, mflag);
 				free(set);
 				break;
 			}
 			case 'p':
 				if (psxrules == NULL)
 					psxrules = optarg;
 				else {
 					fprintf(stderr,
 _("%s: More than one -p option specified\n"),
 						progname);
 					return EXIT_FAILURE;
 				}
 				break;
 			case 't':
 				if (tzdefault != NULL) {
 				  fprintf(stderr,
 					  _("%s: More than one -t option"
 					    " specified\n"),
 					  progname);
 				  return EXIT_FAILURE;
 				}
 				tzdefault = optarg;
 				break;
 			case 'u':
 				setuser(&uflag, optarg);
 				break;
 			case 'y':
 				warning(_("-y ignored"));
 				break;
 			case 'L':
 				if (leapsec == NULL)
 					leapsec = optarg;
 				else {
 					fprintf(stderr,
 _("%s: More than one -L option specified\n"),
 						progname);
 					return EXIT_FAILURE;
 				}
 				break;
 			case 'v':
 				noise = true;
 				break;
 			case 'r':
 				if (timerange_given) {
 				  fprintf(stderr,
 _("%s: More than one -r option specified\n"),
 					  progname);
 				  return EXIT_FAILURE;
 				}
 				if (! timerange_option(optarg)) {
 				  fprintf(stderr,
 _("%s: invalid time range: %s\n"),
 					  progname, optarg);
 				  return EXIT_FAILURE;
 				}
 				timerange_given = true;
 				break;
 			case 'R':
 				if (! redundant_time_option(optarg)) {
 				  fprintf(stderr, _("%s: invalid time: %s\n"),
 					  progname, optarg);
 				  return EXIT_FAILURE;
 				}
 				break;
 			case 's':
 				warning(_("-s ignored"));
 				break;
 		}
 	if (optind == argc - 1 && strcmp(argv[optind], "=") == 0)
 		usage(stderr, EXIT_FAILURE);	/* usage message by request */
 	if (hi_time + (hi_time < ZIC_MAX) < redundant_time) {
 	  fprintf(stderr, _("%s: -R time exceeds -r cutoff\n"), progname);
 	  return EXIT_FAILURE;
 	}
 	if (bloat == 0) {
 	  static char const bloat_default[] = ZIC_BLOAT_DEFAULT;
 	  if (strcmp(bloat_default, "slim") == 0)
 	    bloat = -1;
 	  else if (strcmp(bloat_default, "fat") == 0)
 	    bloat = 1;
 	  else
 	    abort(); /* Configuration error.  */
 	}
 	if (directory == NULL)
 		directory = TZDIR;
 	if (tzdefault == NULL)
 		tzdefault = TZDEFAULT;
 
 	if (optind < argc && leapsec != NULL) {
 		infile(LEAPSEC_FILENUM, leapsec);
 		adjleap();
 	}
 
 	for (k = optind; k < argc; k++)
 	  infile(k, argv[k]);
 	if (errors)
 		return EXIT_FAILURE;
 	associate();
 	change_directory(directory);
 	catch_signals();
 	for (i = 0; i < nzones; i = j) {
 		/*
 		** Find the next non-continuation zone entry.
 		*/
 		for (j = i + 1; j < nzones && zones[j].z_name == NULL; ++j)
 			continue;
 		outzone(&zones[i], j - i);
 	}
 	make_links();
 	if (lcltime != NULL) {
 		eat(COMMAND_LINE_FILENUM, 1);
 		dolink(lcltime, tzdefault, true);
 	}
 	if (psxrules != NULL) {
 		eat(COMMAND_LINE_FILENUM, 1);
 		dolink(psxrules, TZDEFRULES, true);
 	}
 	if (warnings && (ferror(stderr) || fclose(stderr) != 0))
 	  return EXIT_FAILURE;
 	return errors ? EXIT_FAILURE : EXIT_SUCCESS;
 }
 
 static bool
 componentcheck(char const *name, char const *component,
 	       char const *component_end)
 {
 	enum { component_len_max = 14 };
 	ptrdiff_t component_len = component_end - component;
 	if (component_len == 0) {
 	  if (!*name)
 	    error(_("empty file name"));
 	  else
 	    error(_(component == name
 		     ? "file name '%s' begins with '/'"
 		     : *component_end
 		     ? "file name '%s' contains '//'"
 		     : "file name '%s' ends with '/'"),
 		   name);
 	  return false;
 	}
 	if (0 < component_len && component_len <= 2
 	    && component[0] == '.' && component_end[-1] == '.') {
 	  int len = component_len;
 	  error(_("file name '%s' contains '%.*s' component"),
 		name, len, component);
 	  return false;
 	}
 	if (noise) {
 	  if (0 < component_len && component[0] == '-')
 	    warning(_("file name '%s' component contains leading '-'"),
 		    name);
 	  if (component_len_max < component_len)
 	    warning(_("file name '%s' contains overlength component"
 		      " '%.*s...'"),
 		    name, component_len_max, component);
 	}
 	return true;
 }
 
 static bool
 namecheck(const char *name)
 {
 	register char const *cp;
 
 	/* Benign characters in a portable file name.  */
 	static char const benign[] =
 	  "-/_"
 	  "abcdefghijklmnopqrstuvwxyz"
 	  "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
 
 	/* Non-control chars in the POSIX portable character set,
 	   excluding the benign characters.  */
 	static char const printable_and_not_benign[] =
 	  " !\"#$%&'()*+,.0123456789:;<=>?@[\\]^`{|}~";
 
 	register char const *component = name;
 	for (cp = name; *cp; cp++) {
 		unsigned char c = *cp;
 		if (noise && !strchr(benign, c)) {
 			warning((strchr(printable_and_not_benign, c)
 				 ? _("file name '%s' contains byte '%c'")
 				 : _("file name '%s' contains byte '\\%o'")),
 				name, c);
 		}
 		if (c == '/') {
 			if (!componentcheck(name, component, cp))
 			  return false;
 			component = cp + 1;
 		}
 	}
 	return componentcheck(name, component, cp);
 }
 
 /* Return a random uint_fast64_t.  */
 static uint_fast64_t
 get_rand_u64(void)
 {
 #if HAVE_GETRANDOM
   static uint_fast64_t entropy_buffer[max(1, 256 / sizeof(uint_fast64_t))];
   static int nwords;
   if (!nwords) {
     ssize_t s;
     do
       s = getrandom(entropy_buffer, sizeof entropy_buffer, 0);
     while (s < 0 && errno == EINTR);
 
     if (s < 0)
       nwords = -1;
     else
       nwords = s / sizeof *entropy_buffer;
   }
   if (0 < nwords)
     return entropy_buffer[--nwords];
 #endif
 
   /* getrandom didn't work, so fall back on portable code that is
      not the best because the seed isn't cryptographically random and
      'rand' might not be cryptographically secure.  */
   {
     static bool initialized;
     if (!initialized) {
       srand(time(NULL));
       initialized = true;
     }
   }
 
   /* Return a random number if rand() yields a random number and in
      the typical case where RAND_MAX is one less than a power of two.
      In other cases this code yields a sort-of-random number.  */
   {
     uint_fast64_t rand_max = RAND_MAX,
       nrand = rand_max < UINT_FAST64_MAX ? rand_max + 1 : 0,
       rmod = INT_MAX < UINT_FAST64_MAX ? 0 : UINT_FAST64_MAX / nrand + 1,
       r = 0, rmax = 0;
 
     do {
       uint_fast64_t rmax1 = rmax;
       if (rmod) {
 	/* Avoid signed integer overflow on theoretical platforms
 	   where uint_fast64_t promotes to int.  */
 	rmax1 %= rmod;
 	r %= rmod;
       }
       rmax1 = nrand * rmax1 + rand_max;
       r = nrand * r + rand();
       rmax = rmax < rmax1 ? rmax1 : UINT_FAST64_MAX;
     } while (rmax < UINT_FAST64_MAX);
 
     return r;
   }
 }
 
 /* Generate a randomish name in the same directory as *NAME.  If
    *NAMEALLOC, put the name into *NAMEALLOC which is assumed to be
    that returned by a previous call and is thus already almost set up
    and equal to *NAME; otherwise, allocate a new name and put its
    address into both *NAMEALLOC and *NAME.  */
 static void
 random_dirent(char const **name, char **namealloc)
 {
   char const *src = *name;
   char *dst = *namealloc;
   static char const prefix[] = ".zic";
   static char const alphabet[] =
     "abcdefghijklmnopqrstuvwxyz"
     "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
     "0123456789";
   enum { prefixlen = sizeof prefix - 1, alphabetlen = sizeof alphabet - 1 };
   int suffixlen = 6;
   char const *lastslash = strrchr(src, '/');
   ptrdiff_t dirlen = lastslash ? lastslash + 1 - src : 0;
   int i;
   uint_fast64_t r;
   uint_fast64_t base = alphabetlen;
 
   /* BASE**6 */
   uint_fast64_t base__6 = base * base * base * base * base * base;
 
   /* The largest uintmax_t that is a multiple of BASE**6.  Any random
      uintmax_t value that is this value or greater, yields a biased
      remainder when divided by BASE**6.  UNFAIR_MIN equals the
      mathematical value of ((UINTMAX_MAX + 1) - (UINTMAX_MAX + 1) % BASE**6)
      computed without overflow.  */
   uint_fast64_t unfair_min = - ((UINTMAX_MAX % base__6 + 1) % base__6);
 
   if (!dst) {
     dst = emalloc(size_sum(dirlen, prefixlen + suffixlen + 1));
     memcpy(dst, src, dirlen);
     memcpy(dst + dirlen, prefix, prefixlen);
     dst[dirlen + prefixlen + suffixlen] = '\0';
     *name = *namealloc = dst;
   }
 
   do
     r = get_rand_u64();
   while (unfair_min <= r);
 
   for (i = 0; i < suffixlen; i++) {
     dst[dirlen + prefixlen + i] = alphabet[r % alphabetlen];
     r /= alphabetlen;
   }
 }
 
 /* Prepare to write to the file *OUTNAME, using *TEMPNAME to store the
    name of the temporary file that will eventually be renamed to
    *OUTNAME.  Assign the temporary file's name to both *OUTNAME and
    *TEMPNAME.  If *TEMPNAME is null, allocate the name of any such
    temporary file; otherwise, reuse *TEMPNAME's storage, which is
    already set up and only needs its trailing suffix updated.  */
 static FILE *
 open_outfile(char const **outname, char **tempname)
 {
 #if __STDC_VERSION__ < 201112
   static char const fopen_mode[] = "wb";
 #else
   static char const fopen_mode[] = "wbx";
 #endif
 
   FILE *fp;
   bool dirs_made = false;
   if (!*tempname)
     random_dirent(outname, tempname);
 
   /*
    * Remove old file, if any, to snap links.
    */
   if (remove(*outname) != 0 && errno != ENOENT && errno != EISDIR) {
     fprintf(stderr, _("can't remove %s"), *outname);
     exit(EXIT_FAILURE);
   }
 
   while (! (fp = fopen(*outname, fopen_mode))) {
     int fopen_errno = errno;
     if (fopen_errno == ENOENT && !dirs_made) {
       mkdirs(*outname, true);
       dirs_made = true;
     } else if (fopen_errno == EEXIST)
       random_dirent(outname, tempname);
     else {
       fprintf(stderr, _("%s: Can't create %s/%s: %s\n"),
 	      progname, directory, *outname, strerror(fopen_errno));
       exit(EXIT_FAILURE);
     }
   }
 
   return fp;
 }
 
 /* If TEMPNAME, the result is in the temporary file TEMPNAME even
    though the user wanted it in NAME, so rename TEMPNAME to NAME.
    Report an error and exit if there is trouble.  Also, free TEMPNAME.  */
 static void
 rename_dest(char *tempname, char const *name)
 {
   if (tempname) {
     if (rename(tempname, name) != 0) {
       int rename_errno = errno;
       (void)remove(tempname);
       fprintf(stderr, _("%s: rename to %s/%s: %s\n"),
 	      progname, directory, name, strerror(rename_errno));
       exit(EXIT_FAILURE);
     }
     free(tempname);
   }
 }
 
 /* Create symlink contents suitable for symlinking FROM to TO, as a
    freshly allocated string.  FROM should be a relative file name, and
    is relative to the global variable DIRECTORY.  TO can be either
    relative or absolute.  */
 static char *
 relname(char const *target, char const *linkname)
 {
   size_t i, taillen, dir_len = 0, dotdots = 0;
-  ptrdiff_t dotdotetcsize, linksize = min(PTRDIFF_MAX, SIZE_MAX);
+  ptrdiff_t dotdotetcsize, linksize = INDEX_MAX;
   char const *f = target;
   char *result = NULL;
   if (*linkname == '/') {
     /* Make F absolute too.  */
     size_t len = strlen(directory);
     size_t lenslash = len + (len && directory[len - 1] != '/');
     size_t targetsize = strlen(target) + 1;
     linksize = size_sum(lenslash, targetsize);
     f = result = emalloc(linksize);
     memcpy(result, directory, len);
     result[len] = '/';
     memcpy(result + lenslash, target, targetsize);
   }
   for (i = 0; f[i] && f[i] == linkname[i]; i++)
     if (f[i] == '/')
       dir_len = i + 1;
   for (; linkname[i]; i++)
     dotdots += linkname[i] == '/' && linkname[i - 1] != '/';
   taillen = strlen(f + dir_len);
   dotdotetcsize = size_sum(size_product(dotdots, 3), taillen + 1);
   if (dotdotetcsize <= linksize) {
     if (!result)
       result = emalloc(dotdotetcsize);
     for (i = 0; i < dotdots; i++)
       memcpy(result + 3 * i, "../", 3);
     memmove(result + 3 * dotdots, f + dir_len, taillen + 1);
   }
   return result;
 }
 
 static void
 dolink(char const *target, char const *linkname, bool staysymlink)
 {
 	bool linkdirs_made = false;
 	int link_errno;
 	char *tempname = NULL;
 	char const *outname = linkname;
 
 	check_for_signal();
 
 	if (strcmp(target, "-") == 0) {
 	  if (remove(linkname) == 0 || errno == ENOENT || errno == ENOTDIR)
 	    return;
 	  else {
 	    char const *e = strerror(errno);
 	    fprintf(stderr, _("%s: Can't remove %s/%s: %s\n"),
 		    progname, directory, linkname, e);
 	    exit(EXIT_FAILURE);
 	  }
 	}
 
 	while (true) {
 	  if (linkat(AT_FDCWD, target, AT_FDCWD, outname, AT_SYMLINK_FOLLOW)
 	      == 0) {
 	    link_errno = 0;
 	    break;
 	  }
 	  link_errno = errno;
 	  if (link_errno == EXDEV || link_errno == ENOTSUP)
 	    break;
 
 	  if (link_errno == EEXIST) {
 	    staysymlink &= !tempname;
 	    random_dirent(&outname, &tempname);
 	    if (staysymlink && itssymlink(linkname))
 	      break;
 	  } else if (link_errno == ENOENT && !linkdirs_made) {
 	    mkdirs(linkname, true);
 	    linkdirs_made = true;
 	  } else {
 	    fprintf(stderr, _("%s: Can't link %s/%s to %s/%s: %s\n"),
 		    progname, directory, target, directory, outname,
 		    strerror(link_errno));
 	    exit(EXIT_FAILURE);
 	  }
 	}
 	if (link_errno != 0) {
 	  bool absolute = *target == '/';
 	  char *linkalloc = absolute ? NULL : relname(target, linkname);
 	  char const *contents = absolute ? target : linkalloc;
 	  int symlink_errno;
 
 	  while (true) {
 	    if (symlink(contents, outname) == 0) {
 	      symlink_errno = 0;
 	      break;
 	    }
 	    symlink_errno = errno;
 	    if (symlink_errno == EEXIST)
 	      random_dirent(&outname, &tempname);
 	    else if (symlink_errno == ENOENT && !linkdirs_made) {
 	      mkdirs(linkname, true);
 	      linkdirs_made = true;
 	    } else
 	      break;
 	  }
 	  free(linkalloc);
 	  if (symlink_errno == 0) {
 	    if (link_errno != ENOTSUP && link_errno != EEXIST)
 	      warning(_("symbolic link used because hard link failed: %s"),
 		      strerror(link_errno));
 	  } else {
 	    FILE *fp, *tp;
 	    int c;
 	    fp = fopen(target, "rb");
 	    if (!fp) {
 	      char const *e = strerror(errno);
 	      fprintf(stderr, _("%s: Can't read %s/%s: %s\n"),
 		      progname, directory, target, e);
 	      exit(EXIT_FAILURE);
 	    }
 	    tp = open_outfile(&outname, &tempname);
 	    while ((c = getc(fp)) != EOF)
 	      putc(c, tp);
 	    close_file(tp, directory, linkname, tempname);
 	    close_file(fp, directory, target, NULL);
 	    if (link_errno != ENOTSUP)
 	      warning(_("copy used because hard link failed: %s"),
 		      strerror(link_errno));
 	    else if (symlink_errno != ENOTSUP)
 	      warning(_("copy used because symbolic link failed: %s"),
 		      strerror(symlink_errno));
 	  }
 	}
 	rename_dest(tempname, linkname);
 }
 
 /* Return true if NAME is a symbolic link.  */
 static bool
 itssymlink(char const *name)
 {
   char c;
   return 0 <= readlink(name, &c, 1);
 }
 
 /*
 ** Associate sets of rules with zones.
 */
 
 /*
 ** Sort by rule name.
 */
 
 static int
 rcomp(const void *cp1, const void *cp2)
 {
   struct rule const *r1 = cp1, *r2 = cp2;
   return strcmp(r1->r_name, r2->r_name);
 }
 
 static void
 associate(void)
 {
 	register struct zone *	zp;
 	register struct rule *	rp;
 	register ptrdiff_t i, j, base, out;
 
 	if (1 < nrules) {
 		qsort(rules, nrules, sizeof *rules, rcomp);
 		for (i = 0; i < nrules - 1; ++i) {
 			if (strcmp(rules[i].r_name,
 				rules[i + 1].r_name) != 0)
 					continue;
 			if (rules[i].r_filenum == rules[i + 1].r_filenum)
 					continue;
 			eat(rules[i].r_filenum, rules[i].r_linenum);
 			warning(_("same rule name in multiple files"));
 			eat(rules[i + 1].r_filenum, rules[i + 1].r_linenum);
 			warning(_("same rule name in multiple files"));
 			for (j = i + 2; j < nrules; ++j) {
 				if (strcmp(rules[i].r_name,
 					rules[j].r_name) != 0)
 						break;
 				if (rules[i].r_filenum == rules[j].r_filenum)
 						continue;
 				if (rules[i + 1].r_filenum
 				    == rules[j].r_filenum)
 						continue;
 				break;
 			}
 			i = j - 1;
 		}
 	}
 	for (i = 0; i < nzones; ++i) {
 		zp = &zones[i];
 		zp->z_rules = NULL;
 		zp->z_nrules = 0;
 	}
 	for (base = 0; base < nrules; base = out) {
 		rp = &rules[base];
 		for (out = base + 1; out < nrules; ++out)
 			if (strcmp(rp->r_name, rules[out].r_name) != 0)
 				break;
 		for (i = 0; i < nzones; ++i) {
 			zp = &zones[i];
 			if (strcmp(zp->z_rule, rp->r_name) != 0)
 				continue;
 			zp->z_rules = rp;
 			zp->z_nrules = out - base;
 		}
 	}
 	for (i = 0; i < nzones; ++i) {
 		zp = &zones[i];
 		if (zp->z_nrules == 0) {
 			/*
 			** Maybe we have a local standard time offset.
 			*/
 			eat(zp->z_filenum, zp->z_linenum);
 			zp->z_save = getsave(zp->z_rule, &zp->z_isdst);
 			/*
 			** Note, though, that if there's no rule,
 			** a '%s' in the format is a bad thing.
 			*/
 			if (zp->z_format_specifier == 's')
 				error("%s", _("%s in ruleless zone"));
 		}
 	}
 	if (errors)
 		exit(EXIT_FAILURE);
 }
 
 /* Read a text line from FP into BUF, which is of size BUFSIZE.
    Terminate it with a NUL byte instead of a newline.
    Return true if successful, false if EOF.
    On error, report the error and exit.  */
 static bool
 inputline(FILE *fp, char *buf, ptrdiff_t bufsize)
 {
   ptrdiff_t linelen = 0, ch;
   while ((ch = getc(fp)) != '\n') {
     if (ch < 0) {
       if (ferror(fp)) {
 	error(_("input error"));
 	exit(EXIT_FAILURE);
       }
       if (linelen == 0)
 	return false;
       error(_("unterminated line"));
       exit(EXIT_FAILURE);
     }
     if (!ch) {
       error(_("NUL input byte"));
       exit(EXIT_FAILURE);
     }
     buf[linelen++] = ch;
     if (linelen == bufsize) {
       error(_("line too long"));
       exit(EXIT_FAILURE);
     }
   }
   buf[linelen] = '\0';
   return true;
 }
 
 static void
 infile(int fnum, char const *name)
 {
 	register FILE *			fp;
 	register const struct lookup *	lp;
 	register bool			wantcont;
 	register lineno			num;
 
 	if (strcmp(name, "-") == 0) {
 		fp = stdin;
 	} else if ((fp = fopen(name, "r")) == NULL) {
 		const char *e = strerror(errno);
 
 		fprintf(stderr, _("%s: Can't open %s: %s\n"),
 			progname, name, e);
 		exit(EXIT_FAILURE);
 	}
 	wantcont = false;
 	for (num = 1; ; ++num) {
 		enum { bufsize_bound
-		  = (min(INT_MAX, min(PTRDIFF_MAX, SIZE_MAX))
-		     / FORMAT_LEN_GROWTH_BOUND) };
+		  = (min(INT_MAX, INDEX_MAX) / FORMAT_LEN_GROWTH_BOUND) };
 		char buf[min(_POSIX2_LINE_MAX, bufsize_bound)];
 		int nfields;
 		char *fields[MAX_FIELDS];
 		eat(fnum, num);
 		if (!inputline(fp, buf, sizeof buf))
 		  break;
 		nfields = getfields(buf, fields,
 				    sizeof fields / sizeof *fields);
 		if (nfields == 0) {
 			/* nothing to do */
 		} else if (wantcont) {
 			wantcont = inzcont(fields, nfields);
 		} else {
 			struct lookup const *line_codes
 			  = fnum < 0 ? leap_line_codes : zi_line_codes;
 			lp = byword(fields[0], line_codes);
 			if (lp == NULL)
 				error(_("input line of unknown type"));
 			else switch (lp->l_value) {
 				case LC_RULE:
 					inrule(fields, nfields);
 					wantcont = false;
 					break;
 				case LC_ZONE:
 					wantcont = inzone(fields, nfields);
 					break;
 				case LC_LINK:
 					inlink(fields, nfields);
 					wantcont = false;
 					break;
 				case LC_LEAP:
 					inleap(fields, nfields);
 					wantcont = false;
 					break;
 				case LC_EXPIRES:
 					inexpires(fields, nfields);
 					wantcont = false;
 					break;
 				default: unreachable();
 			}
 		}
 	}
 	close_file(fp, NULL, filename(fnum), NULL);
 	if (wantcont)
 		error(_("expected continuation line not found"));
 }
 
 /*
 ** Convert a string of one of the forms
 **	h	-h	hh:mm	-hh:mm	hh:mm:ss	-hh:mm:ss
 ** into a number of seconds.
 ** A null string maps to zero.
 ** Call error with errstring and return zero on errors.
 */
 
 static zic_t
 gethms(char const *string, char const *errstring)
 {
 	zic_t	hh;
 	int sign, mm = 0, ss = 0;
 	char hhx, mmx, ssx, xr = '0', xs;
 	int tenths = 0;
 	bool ok = true;
 
 	if (string == NULL || *string == '\0')
 		return 0;
 	if (*string == '-') {
 		sign = -1;
 		++string;
 	} else	sign = 1;
 	switch (sscanf(string,
 		       "%"SCNdZIC"%c%d%c%d%c%1d%*[0]%c%*[0123456789]%c",
 		       &hh, &hhx, &mm, &mmx, &ss, &ssx, &tenths, &xr, &xs)) {
 	  default: ok = false; break;
 	  case 8:
 	    ok = '0' <= xr && xr <= '9';
 	    ATTRIBUTE_FALLTHROUGH;
 	  case 7:
 	    ok &= ssx == '.';
 	    if (ok && noise)
 	      warning(_("fractional seconds rejected by"
 			" pre-2018 versions of zic"));
 	    ATTRIBUTE_FALLTHROUGH;
 	  case 5: ok &= mmx == ':'; ATTRIBUTE_FALLTHROUGH;
 	  case 3: ok &= hhx == ':'; ATTRIBUTE_FALLTHROUGH;
 	  case 1: break;
 	}
 	if (!ok) {
 			error("%s", errstring);
 			return 0;
 	}
 	if (hh < 0 ||
 		mm < 0 || mm >= MINSPERHOUR ||
 		ss < 0 || ss > SECSPERMIN) {
 			error("%s", errstring);
 			return 0;
 	}
 	if (ZIC_MAX / SECSPERHOUR < hh) {
 		error(_("time overflow"));
 		return 0;
 	}
 	ss += 5 + ((ss ^ 1) & (xr == '0')) <= tenths; /* Round to even.  */
 	if (noise && (hh > HOURSPERDAY ||
 		(hh == HOURSPERDAY && (mm != 0 || ss != 0))))
 warning(_("values over 24 hours not handled by pre-2007 versions of zic"));
 	return oadd(sign * hh * SECSPERHOUR,
 		    sign * (mm * SECSPERMIN + ss));
 }
 
 static zic_t
 getsave(char *field, bool *isdst)
 {
   int dst = -1;
   zic_t save;
   ptrdiff_t fieldlen = strlen(field);
   if (fieldlen != 0) {
     char *ep = field + fieldlen - 1;
     switch (*ep) {
       case 'd': dst = 1; *ep = '\0'; break;
       case 's': dst = 0; *ep = '\0'; break;
     }
   }
   save = gethms(field, _("invalid saved time"));
   *isdst = dst < 0 ? save != 0 : dst;
   return save;
 }
 
 static void
 inrule(char **fields, int nfields)
 {
 	struct rule r = { 0 };
 
 	if (nfields != RULE_FIELDS) {
 		error(_("wrong number of fields on Rule line"));
 		return;
 	}
 	switch (*fields[RF_NAME]) {
 	  case '\0':
 	  case ' ': case '\f': case '\n': case '\r': case '\t': case '\v':
 	  case '+': case '-':
 	  case '0': case '1': case '2': case '3': case '4':
 	  case '5': case '6': case '7': case '8': case '9':
 		error(_("Invalid rule name \"%s\""), fields[RF_NAME]);
 		return;
 	}
 	r.r_filenum = filenum;
 	r.r_linenum = linenum;
 	r.r_save = getsave(fields[RF_SAVE], &r.r_isdst);
 	if (!rulesub(&r, fields[RF_LOYEAR], fields[RF_HIYEAR],
 		     fields[RF_COMMAND], fields[RF_MONTH], fields[RF_DAY],
 		     fields[RF_TOD]))
 	  return;
 	r.r_name = estrdup(fields[RF_NAME]);
 	r.r_abbrvar = estrdup(fields[RF_ABBRVAR]);
 	if (max_abbrvar_len < strlen(r.r_abbrvar))
 		max_abbrvar_len = strlen(r.r_abbrvar);
 	rules = growalloc(rules, sizeof *rules, nrules, &nrules_alloc);
 	rules[nrules++] = r;
 }
 
 static bool
 inzone(char **fields, int nfields)
 {
 	register ptrdiff_t i;
 
 	if (nfields < ZONE_MINFIELDS || nfields > ZONE_MAXFIELDS) {
 		error(_("wrong number of fields on Zone line"));
 		return false;
 	}
 	if (lcltime != NULL && strcmp(fields[ZF_NAME], tzdefault) == 0) {
 		error(
 _("\"Zone %s\" line and -l option are mutually exclusive"),
 			tzdefault);
 		return false;
 	}
 	if (strcmp(fields[ZF_NAME], TZDEFRULES) == 0 && psxrules != NULL) {
 		error(
 _("\"Zone %s\" line and -p option are mutually exclusive"),
 			TZDEFRULES);
 		return false;
 	}
 	for (i = 0; i < nzones; ++i)
 		if (zones[i].z_name != NULL &&
 			strcmp(zones[i].z_name, fields[ZF_NAME]) == 0) {
 				error(_("duplicate zone name %s"
 					" (file \"%s\", line %"PRIdMAX")"),
 				      fields[ZF_NAME],
 				      filename(zones[i].z_filenum),
 				      zones[i].z_linenum);
 				return false;
 		}
 	return inzsub(fields, nfields, false);
 }
 
 static bool
 inzcont(char **fields, int nfields)
 {
 	if (nfields < ZONEC_MINFIELDS || nfields > ZONEC_MAXFIELDS) {
 		error(_("wrong number of fields on Zone continuation line"));
 		return false;
 	}
 	return inzsub(fields, nfields, true);
 }
 
 static bool
 inzsub(char **fields, int nfields, bool iscont)
 {
 	register char *		cp;
 	char *			cp1;
 	struct zone		z = { 0 };
 	int format_len;
 	register int		i_stdoff, i_rule, i_format;
 	register int		i_untilyear, i_untilmonth;
 	register int		i_untilday, i_untiltime;
 	register bool		hasuntil;
 
 	if (iscont) {
 		i_stdoff = ZFC_STDOFF;
 		i_rule = ZFC_RULE;
 		i_format = ZFC_FORMAT;
 		i_untilyear = ZFC_TILYEAR;
 		i_untilmonth = ZFC_TILMONTH;
 		i_untilday = ZFC_TILDAY;
 		i_untiltime = ZFC_TILTIME;
 	} else if (!namecheck(fields[ZF_NAME]))
 		return false;
 	else {
 		i_stdoff = ZF_STDOFF;
 		i_rule = ZF_RULE;
 		i_format = ZF_FORMAT;
 		i_untilyear = ZF_TILYEAR;
 		i_untilmonth = ZF_TILMONTH;
 		i_untilday = ZF_TILDAY;
 		i_untiltime = ZF_TILTIME;
 	}
 	z.z_filenum = filenum;
 	z.z_linenum = linenum;
 	z.z_stdoff = gethms(fields[i_stdoff], _("invalid UT offset"));
 	if ((cp = strchr(fields[i_format], '%')) != 0) {
 		if ((*++cp != 's' && *cp != 'z') || strchr(cp, '%')
 		    || strchr(fields[i_format], '/')) {
 			error(_("invalid abbreviation format"));
 			return false;
 		}
 	}
 	z.z_format_specifier = cp ? *cp : '\0';
 	format_len = strlen(fields[i_format]);
 	if (max_format_len < format_len)
 	  max_format_len = format_len;
 	hasuntil = nfields > i_untilyear;
 	if (hasuntil) {
 		z.z_untilrule.r_filenum = filenum;
 		z.z_untilrule.r_linenum = linenum;
 		if (!rulesub(
 			&z.z_untilrule,
 			fields[i_untilyear],
 			"only",
 			"",
 			(nfields > i_untilmonth) ?
 			fields[i_untilmonth] : "Jan",
 			(nfields > i_untilday) ? fields[i_untilday] : "1",
 			(nfields > i_untiltime) ? fields[i_untiltime] : "0"))
 		  return false;
 		z.z_untiltime = rpytime(&z.z_untilrule,
 			z.z_untilrule.r_loyear);
 		if (iscont && nzones > 0 &&
 			z.z_untiltime > min_time &&
 			z.z_untiltime < max_time &&
 			zones[nzones - 1].z_untiltime > min_time &&
 			zones[nzones - 1].z_untiltime < max_time &&
 			zones[nzones - 1].z_untiltime >= z.z_untiltime) {
 				error(_(
 "Zone continuation line end time is not after end time of previous line"
 					));
 				return false;
 		}
 	}
 	z.z_name = iscont ? NULL : estrdup(fields[ZF_NAME]);
 	z.z_rule = estrdup(fields[i_rule]);
 	z.z_format = cp1 = estrdup(fields[i_format]);
 	if (z.z_format_specifier == 'z') {
 	  cp1[cp - fields[i_format]] = 's';
 	  if (noise)
 	    warning(_("format '%s' not handled by pre-2015 versions of zic"),
 		    fields[i_format]);
 	}
 	zones = growalloc(zones, sizeof *zones, nzones, &nzones_alloc);
 	zones[nzones++] = z;
 	/*
 	** If there was an UNTIL field on this line,
 	** there's more information about the zone on the next line.
 	*/
 	return hasuntil;
 }
 
 static zic_t
 getleapdatetime(char **fields, bool expire_line)
 {
 	register const char *		cp;
 	register const struct lookup *	lp;
 	register zic_t			i, j;
 	zic_t				year;
 	int				month, day;
 	zic_t				dayoff, tod;
 	zic_t				t;
 	char xs;
 
 	dayoff = 0;
 	cp = fields[LP_YEAR];
 	if (sscanf(cp, "%"SCNdZIC"%c", &year, &xs) != 1) {
 		/*
 		** Leapin' Lizards!
 		*/
 		error(_("invalid leaping year"));
 		return -1;
 	}
 	if (!expire_line) {
 	    if (!leapseen || leapmaxyear < year)
 		leapmaxyear = year;
 	    if (!leapseen || leapminyear > year)
 		leapminyear = year;
 	    leapseen = true;
 	}
 	j = EPOCH_YEAR;
 	while (j != year) {
 		if (year > j) {
 			i = len_years[isleap(j)];
 			++j;
 		} else {
 			--j;
 			i = -len_years[isleap(j)];
 		}
 		dayoff = oadd(dayoff, i);
 	}
 	if ((lp = byword(fields[LP_MONTH], mon_names)) == NULL) {
 		error(_("invalid month name"));
 		return -1;
 	}
 	month = lp->l_value;
 	j = TM_JANUARY;
 	while (j != month) {
 		i = len_months[isleap(year)][j];
 		dayoff = oadd(dayoff, i);
 		++j;
 	}
 	cp = fields[LP_DAY];
 	if (sscanf(cp, "%d%c", &day, &xs) != 1 ||
 		day <= 0 || day > len_months[isleap(year)][month]) {
 			error(_("invalid day of month"));
 			return -1;
 	}
 	dayoff = oadd(dayoff, day - 1);
 	if (dayoff < min_time / SECSPERDAY) {
 		error(_("time too small"));
 		return -1;
 	}
 	if (dayoff > max_time / SECSPERDAY) {
 		error(_("time too large"));
 		return -1;
 	}
 	t = dayoff * SECSPERDAY;
 	tod = gethms(fields[LP_TIME], _("invalid time of day"));
 	t = tadd(t, tod);
 	if (t < 0)
 	  error(_("leap second precedes Epoch"));
 	return t;
 }
 
 static void
 inleap(char **fields, int nfields)
 {
   if (nfields != LEAP_FIELDS)
     error(_("wrong number of fields on Leap line"));
   else {
     zic_t t = getleapdatetime(fields, false);
     if (0 <= t) {
       struct lookup const *lp = byword(fields[LP_ROLL], leap_types);
       if (!lp)
 	error(_("invalid Rolling/Stationary field on Leap line"));
       else {
 	int correction = 0;
 	if (!fields[LP_CORR][0]) /* infile() turns "-" into "".  */
 	  correction = -1;
 	else if (strcmp(fields[LP_CORR], "+") == 0)
 	  correction = 1;
 	else
 	  error(_("invalid CORRECTION field on Leap line"));
 	if (correction)
 	  leapadd(t, correction, lp->l_value);
       }
     }
   }
 }
 
 static void
 inexpires(char **fields, int nfields)
 {
   if (nfields != EXPIRES_FIELDS)
     error(_("wrong number of fields on Expires line"));
   else if (0 <= leapexpires)
     error(_("multiple Expires lines"));
   else
     leapexpires = getleapdatetime(fields, true);
 }
 
 static void
 inlink(char **fields, int nfields)
 {
 	struct link	l;
 
 	if (nfields != LINK_FIELDS) {
 		error(_("wrong number of fields on Link line"));
 		return;
 	}
 	if (*fields[LF_TARGET] == '\0') {
 		error(_("blank TARGET field on Link line"));
 		return;
 	}
 	if (! namecheck(fields[LF_LINKNAME]))
 	  return;
 	l.l_filenum = filenum;
 	l.l_linenum = linenum;
 	l.l_target = estrdup(fields[LF_TARGET]);
 	l.l_linkname = estrdup(fields[LF_LINKNAME]);
 	links = growalloc(links, sizeof *links, nlinks, &nlinks_alloc);
 	links[nlinks++] = l;
 }
 
 static bool
 rulesub(struct rule *rp, const char *loyearp, const char *hiyearp,
 	const char *typep, const char *monthp, const char *dayp,
 	const char *timep)
 {
 	register const struct lookup *	lp;
 	register const char *		cp;
 	register char *			dp;
 	register char *			ep;
 	char xs;
 
 	if ((lp = byword(monthp, mon_names)) == NULL) {
 		error(_("invalid month name"));
 		return false;
 	}
 	rp->r_month = lp->l_value;
 	rp->r_todisstd = false;
 	rp->r_todisut = false;
 	dp = estrdup(timep);
 	if (*dp != '\0') {
 		ep = dp + strlen(dp) - 1;
 		switch (lowerit(*ep)) {
 			case 's':	/* Standard */
 				rp->r_todisstd = true;
 				rp->r_todisut = false;
 				*ep = '\0';
 				break;
 			case 'w':	/* Wall */
 				rp->r_todisstd = false;
 				rp->r_todisut = false;
 				*ep = '\0';
 				break;
 			case 'g':	/* Greenwich */
 			case 'u':	/* Universal */
 			case 'z':	/* Zulu */
 				rp->r_todisstd = true;
 				rp->r_todisut = true;
 				*ep = '\0';
 				break;
 		}
 	}
 	rp->r_tod = gethms(dp, _("invalid time of day"));
 	free(dp);
 	/*
 	** Year work.
 	*/
 	cp = loyearp;
 	lp = byword(cp, begin_years);
 	rp->r_lowasnum = lp == NULL;
 	if (!rp->r_lowasnum) switch (lp->l_value) {
 		case YR_MINIMUM:
 			rp->r_loyear = ZIC_MIN;
 			break;
 		case YR_MAXIMUM:
 			rp->r_loyear = ZIC_MAX;
 			break;
 		default: unreachable();
 	} else if (sscanf(cp, "%"SCNdZIC"%c", &rp->r_loyear, &xs) != 1) {
 		error(_("invalid starting year"));
 		return false;
 	}
 	cp = hiyearp;
 	lp = byword(cp, end_years);
 	rp->r_hiwasnum = lp == NULL;
 	if (!rp->r_hiwasnum) switch (lp->l_value) {
 		case YR_MINIMUM:
 			rp->r_hiyear = ZIC_MIN;
 			break;
 		case YR_MAXIMUM:
 			rp->r_hiyear = ZIC_MAX;
 			break;
 		case YR_ONLY:
 			rp->r_hiyear = rp->r_loyear;
 			break;
 		default: unreachable();
 	} else if (sscanf(cp, "%"SCNdZIC"%c", &rp->r_hiyear, &xs) != 1) {
 		error(_("invalid ending year"));
 		return false;
 	}
 	if (rp->r_loyear > rp->r_hiyear) {
 		error(_("starting year greater than ending year"));
 		return false;
 	}
 	if (*typep != '\0') {
 		error(_("year type \"%s\" is unsupported; use \"-\" instead"),
 			typep);
 		return false;
 	}
 	/*
 	** Day work.
 	** Accept things such as:
 	**	1
 	**	lastSunday
 	**	last-Sunday (undocumented; warn about this)
 	**	Sun<=20
 	**	Sun>=7
 	*/
 	dp = estrdup(dayp);
 	if ((lp = byword(dp, lasts)) != NULL) {
 		rp->r_dycode = DC_DOWLEQ;
 		rp->r_wday = lp->l_value;
 		rp->r_dayofmonth = len_months[1][rp->r_month];
 	} else {
 		if ((ep = strchr(dp, '<')) != 0)
 			rp->r_dycode = DC_DOWLEQ;
 		else if ((ep = strchr(dp, '>')) != 0)
 			rp->r_dycode = DC_DOWGEQ;
 		else {
 			ep = dp;
 			rp->r_dycode = DC_DOM;
 		}
 		if (rp->r_dycode != DC_DOM) {
 			*ep++ = 0;
 			if (*ep++ != '=') {
 				error(_("invalid day of month"));
 				free(dp);
 				return false;
 			}
 			if ((lp = byword(dp, wday_names)) == NULL) {
 				error(_("invalid weekday name"));
 				free(dp);
 				return false;
 			}
 			rp->r_wday = lp->l_value;
 		}
 		if (sscanf(ep, "%d%c", &rp->r_dayofmonth, &xs) != 1 ||
 			rp->r_dayofmonth <= 0 ||
 			(rp->r_dayofmonth > len_months[1][rp->r_month])) {
 				error(_("invalid day of month"));
 				free(dp);
 				return false;
 		}
 	}
 	free(dp);
 	return true;
 }
 
 static void
 convert(uint_fast32_t val, char *buf)
 {
 	register int	i;
 	register int	shift;
 	unsigned char *const b = (unsigned char *) buf;
 
 	for (i = 0, shift = 24; i < 4; ++i, shift -= 8)
 	  b[i] = (val >> shift) & 0xff;
 }
 
 static void
 convert64(uint_fast64_t val, char *buf)
 {
 	register int	i;
 	register int	shift;
 	unsigned char *const b = (unsigned char *) buf;
 
 	for (i = 0, shift = 56; i < 8; ++i, shift -= 8)
 	  b[i] = (val >> shift) & 0xff;
 }
 
 static void
 puttzcode(zic_t val, FILE *fp)
 {
 	char	buf[4];
 
 	convert(val, buf);
 	fwrite(buf, sizeof buf, 1, fp);
 }
 
 static void
 puttzcodepass(zic_t val, FILE *fp, int pass)
 {
   if (pass == 1)
     puttzcode(val, fp);
   else {
 	char	buf[8];
 
 	convert64(val, buf);
 	fwrite(buf, sizeof buf, 1, fp);
   }
 }
 
 static int
 atcomp(const void *avp, const void *bvp)
 {
   struct attype const *ap = avp, *bp = bvp;
   zic_t a = ap->at, b = bp->at;
   return a < b ? -1 : a > b;
 }
 
 struct timerange {
   int defaulttype;
   ptrdiff_t base, count;
   int leapbase, leapcount;
   bool leapexpiry;
 };
 
 static struct timerange
 limitrange(struct timerange r, zic_t lo, zic_t hi,
 	   zic_t const *ats, unsigned char const *types)
 {
   /* Omit ordinary transitions < LO.  */
   while (0 < r.count && ats[r.base] < lo) {
     r.defaulttype = types[r.base];
     r.count--;
     r.base++;
   }
 
   /* Omit as many initial leap seconds as possible, such that the
      first leap second in the truncated list is <= LO, and is a
      positive leap second if and only if it has a positive correction.
      This supports common TZif readers that assume that the first leap
      second is positive if and only if its correction is positive.  */
   while (1 < r.leapcount && trans[r.leapbase + 1] <= lo) {
     r.leapcount--;
     r.leapbase++;
   }
   while (0 < r.leapbase
 	 && ((corr[r.leapbase - 1] < corr[r.leapbase])
 	     != (0 < corr[r.leapbase]))) {
     r.leapcount++;
     r.leapbase--;
   }
 
 
   /* Omit ordinary and leap second transitions greater than HI + 1.  */
   if (hi < max_time) {
     while (0 < r.count && hi + 1 < ats[r.base + r.count - 1])
       r.count--;
     while (0 < r.leapcount && hi + 1 < trans[r.leapbase + r.leapcount - 1])
       r.leapcount--;
   }
 
   /* Determine whether to append an expiration to the leap second table.  */
   r.leapexpiry = 0 <= leapexpires && leapexpires - 1 <= hi;
 
   return r;
 }
 
 static void
 writezone(const char *const name, const char *const string, char version,
 	  int defaulttype)
 {
 	register FILE *			fp;
 	register ptrdiff_t		i, j;
 	register size_t			u;
 	register int			pass;
 	char *tempname = NULL;
 	char const *outname = name;
 
 	/* Allocate the ATS and TYPES arrays via a single malloc,
 	   as this is a bit faster.  Do not malloc(0) if !timecnt,
 	   as that might return NULL even on success.  */
 	zic_t *ats = emalloc(align_to(size_product(timecnt + !timecnt,
 						   sizeof *ats + 1),
 				      alignof(zic_t)));
 	void *typesptr = ats + timecnt;
 	unsigned char *types = typesptr;
 	struct timerange rangeall = {0}, range32, range64;
 
 	/*
 	** Sort.
 	*/
 	if (timecnt > 1)
 		qsort(attypes, timecnt, sizeof *attypes, atcomp);
 	/*
 	** Optimize.
 	*/
 	{
 		ptrdiff_t fromi, toi;
 
 		toi = 0;
 		fromi = 0;
 		for ( ; fromi < timecnt; ++fromi) {
 			if (toi != 0
 			    && ((attypes[fromi].at
 				 + utoffs[attypes[toi - 1].type])
 				<= (attypes[toi - 1].at
 				    + utoffs[toi == 1 ? 0
 					     : attypes[toi - 2].type]))) {
 					attypes[toi - 1].type =
 						attypes[fromi].type;
 					continue;
 			}
 			if (toi == 0
 			    || attypes[fromi].dontmerge
 			    || (utoffs[attypes[toi - 1].type]
 				!= utoffs[attypes[fromi].type])
 			    || (isdsts[attypes[toi - 1].type]
 				!= isdsts[attypes[fromi].type])
 			    || (desigidx[attypes[toi - 1].type]
 				!= desigidx[attypes[fromi].type]))
 					attypes[toi++] = attypes[fromi];
 		}
 		timecnt = toi;
 	}
 
 	if (noise && timecnt > 1200) {
 	  if (timecnt > TZ_MAX_TIMES)
 		warning(_("reference clients mishandle"
 			  " more than %d transition times"),
 			TZ_MAX_TIMES);
 	  else
 		warning(_("pre-2014 clients may mishandle"
 			  " more than 1200 transition times"));
 	}
 	/*
 	** Transfer.
 	*/
 	for (i = 0; i < timecnt; ++i) {
 		ats[i] = attypes[i].at;
 		types[i] = attypes[i].type;
 	}
 
 	/*
 	** Correct for leap seconds.
 	*/
 	for (i = 0; i < timecnt; ++i) {
 		j = leapcnt;
 		while (--j >= 0)
 			if (ats[i] > trans[j] - corr[j]) {
 				ats[i] = tadd(ats[i], corr[j]);
 				break;
 			}
 	}
 
 	rangeall.defaulttype = defaulttype;
 	rangeall.count = timecnt;
 	rangeall.leapcount = leapcnt;
 	range64 = limitrange(rangeall, lo_time,
 			     max(hi_time,
 				 redundant_time - (ZIC_MIN < redundant_time)),
 			     ats, types);
 	range32 = limitrange(range64, ZIC32_MIN, ZIC32_MAX, ats, types);
 
 	/* TZif version 4 is needed if a no-op transition is appended to
 	   indicate the expiration of the leap second table, or if the first
 	   leap second transition is not to a +1 or -1 correction.  */
 	for (pass = 1; pass <= 2; pass++) {
 	  struct timerange const *r = pass == 1 ? &range32 : &range64;
 	  if (pass == 1 && !want_bloat())
 	    continue;
 	  if (r->leapexpiry) {
 	    if (noise)
 	      warning(_("%s: pre-2021b clients may mishandle"
 			" leap second expiry"),
 		      name);
 	    version = '4';
 	  }
 	  if (0 < r->leapcount
 	      && corr[r->leapbase] != 1 && corr[r->leapbase] != -1) {
 	    if (noise)
 	      warning(_("%s: pre-2021b clients may mishandle"
 			" leap second table truncation"),
 		      name);
 	    version = '4';
 	  }
 	  if (version == '4')
 	    break;
 	}
 
 	fp = open_outfile(&outname, &tempname);
 
 	for (pass = 1; pass <= 2; ++pass) {
 		register ptrdiff_t thistimei, thistimecnt, thistimelim;
 		register int	thisleapi, thisleapcnt, thisleaplim;
 		struct tzhead tzh;
 		int pretranstype = -1, thisdefaulttype;
 		bool locut, hicut, thisleapexpiry;
 		zic_t lo, thismin, thismax;
 		int old0;
 		char		omittype[TZ_MAX_TYPES];
 		int		typemap[TZ_MAX_TYPES];
 		int		thistypecnt, stdcnt, utcnt;
 		char		thischars[TZ_MAX_CHARS];
 		int		thischarcnt;
 		bool		toomanytimes;
 		int		indmap[TZ_MAX_CHARS];
 
 		if (pass == 1) {
 			thisdefaulttype = range32.defaulttype;
 			thistimei = range32.base;
 			thistimecnt = range32.count;
 			toomanytimes = thistimecnt >> 31 >> 1 != 0;
 			thisleapi = range32.leapbase;
 			thisleapcnt = range32.leapcount;
 			thisleapexpiry = range32.leapexpiry;
 			thismin = ZIC32_MIN;
 			thismax = ZIC32_MAX;
 		} else {
 			thisdefaulttype = range64.defaulttype;
 			thistimei = range64.base;
 			thistimecnt = range64.count;
 			toomanytimes = thistimecnt >> 31 >> 31 >> 2 != 0;
 			thisleapi = range64.leapbase;
 			thisleapcnt = range64.leapcount;
 			thisleapexpiry = range64.leapexpiry;
 			thismin = min_time;
 			thismax = max_time;
 		}
 		if (toomanytimes)
 		  error(_("too many transition times"));
 
 		locut = thismin < lo_time && lo_time <= thismax;
 		hicut = thismin <= hi_time && hi_time < thismax;
 		thistimelim = thistimei + thistimecnt;
 		memset(omittype, true, typecnt);
 
 		/* Determine whether to output a transition before the first
 		   transition in range.  This is needed when the output is
 		   truncated at the start, and is also useful when catering to
 		   buggy 32-bit clients that do not use time type 0 for
 		   timestamps before the first transition.  */
 		if ((locut || (pass == 1 && thistimei))
 		    && ! (thistimecnt && ats[thistimei] == lo_time)) {
 		  pretranstype = thisdefaulttype;
 		  omittype[pretranstype] = false;
 		}
 
 		/* Arguably the default time type in the 32-bit data
 		   should be range32.defaulttype, which is suited for
 		   timestamps just before ZIC32_MIN.  However, zic
 		   traditionally used the time type of the indefinite
 		   past instead.  Internet RFC 8532 says readers should
 		   ignore 32-bit data, so this discrepancy matters only
 		   to obsolete readers where the traditional type might
 		   be more appropriate even if it's "wrong".  So, use
 		   the historical zic value, unless -r specifies a low
 		   cutoff that excludes some 32-bit timestamps.  */
 		if (pass == 1 && lo_time <= thismin)
 		  thisdefaulttype = range64.defaulttype;
 
 		if (locut)
 		  thisdefaulttype = unspecifiedtype;
 		omittype[thisdefaulttype] = false;
 		for (i = thistimei; i < thistimelim; i++)
 		  omittype[types[i]] = false;
 		if (hicut)
 		  omittype[unspecifiedtype] = false;
 
 		/* Reorder types to make THISDEFAULTTYPE type 0.
 		   Use TYPEMAP to swap OLD0 and THISDEFAULTTYPE so that
 		   THISDEFAULTTYPE appears as type 0 in the output instead
 		   of OLD0.  TYPEMAP also omits unused types.  */
 		old0 = strlen(omittype);
 
 #ifndef LEAVE_SOME_PRE_2011_SYSTEMS_IN_THE_LURCH
 		/*
 		** For some pre-2011 systems: if the last-to-be-written
 		** standard (or daylight) type has an offset different from the
 		** most recently used offset,
 		** append an (unused) copy of the most recently used type
 		** (to help get global "altzone" and "timezone" variables
 		** set correctly).
 		*/
 		if (want_bloat()) {
 			register int	mrudst, mrustd, hidst, histd, type;
 
 			hidst = histd = mrudst = mrustd = -1;
 			if (0 <= pretranstype) {
 			  if (isdsts[pretranstype])
 			    mrudst = pretranstype;
 			  else
 			    mrustd = pretranstype;
 			}
 			for (i = thistimei; i < thistimelim; i++)
 				if (isdsts[types[i]])
 					mrudst = types[i];
 				else	mrustd = types[i];
 			for (i = old0; i < typecnt; i++) {
 			  int h = (i == old0 ? thisdefaulttype
 				   : i == thisdefaulttype ? old0 : i);
 			  if (!omittype[h]) {
 			    if (isdsts[h])
 			      hidst = i;
 			    else
 			      histd = i;
 			  }
 			}
 			if (hidst >= 0 && mrudst >= 0 && hidst != mrudst &&
 				utoffs[hidst] != utoffs[mrudst]) {
 					isdsts[mrudst] = -1;
 					type = addtype(utoffs[mrudst],
 						&chars[desigidx[mrudst]],
 						true,
 						ttisstds[mrudst],
 						ttisuts[mrudst]);
 					isdsts[mrudst] = 1;
 					omittype[type] = false;
 			}
 			if (histd >= 0 && mrustd >= 0 && histd != mrustd &&
 				utoffs[histd] != utoffs[mrustd]) {
 					isdsts[mrustd] = -1;
 					type = addtype(utoffs[mrustd],
 						&chars[desigidx[mrustd]],
 						false,
 						ttisstds[mrustd],
 						ttisuts[mrustd]);
 					isdsts[mrustd] = 0;
 					omittype[type] = false;
 			}
 		}
 #endif /* !defined LEAVE_SOME_PRE_2011_SYSTEMS_IN_THE_LURCH */
 		thistypecnt = 0;
 		for (i = old0; i < typecnt; i++)
 		  if (!omittype[i])
 		    typemap[i == old0 ? thisdefaulttype
 			    : i == thisdefaulttype ? old0 : i]
 		      = thistypecnt++;
 
 		for (u = 0; u < sizeof indmap / sizeof indmap[0]; ++u)
 			indmap[u] = -1;
 		thischarcnt = stdcnt = utcnt = 0;
 		for (i = old0; i < typecnt; i++) {
 			register char *	thisabbr;
 
 			if (omittype[i])
 				continue;
 			if (ttisstds[i])
 			  stdcnt = thistypecnt;
 			if (ttisuts[i])
 			  utcnt = thistypecnt;
 			if (indmap[desigidx[i]] >= 0)
 				continue;
 			thisabbr = &chars[desigidx[i]];
 			for (j = 0; j < thischarcnt; ++j)
 				if (strcmp(&thischars[j], thisabbr) == 0)
 					break;
 			if (j == thischarcnt) {
 				strcpy(&thischars[thischarcnt], thisabbr);
 				thischarcnt += strlen(thisabbr) + 1;
 			}
 			indmap[desigidx[i]] = j;
 		}
 		if (pass == 1 && !want_bloat()) {
 		  hicut = thisleapexpiry = false;
 		  pretranstype = -1;
 		  thistimecnt = thisleapcnt = 0;
 		  thistypecnt = thischarcnt = 1;
 		}
 #define DO(field)	fwrite(tzh.field, sizeof tzh.field, 1, fp)
 		memset(&tzh, 0, sizeof tzh);
 		memcpy(tzh.tzh_magic, TZ_MAGIC, sizeof tzh.tzh_magic);
 		tzh.tzh_version[0] = version;
 		convert(utcnt, tzh.tzh_ttisutcnt);
 		convert(stdcnt, tzh.tzh_ttisstdcnt);
 		convert(thisleapcnt + thisleapexpiry, tzh.tzh_leapcnt);
 		convert((0 <= pretranstype) + thistimecnt + hicut,
 			tzh.tzh_timecnt);
 		convert(thistypecnt, tzh.tzh_typecnt);
 		convert(thischarcnt, tzh.tzh_charcnt);
 		DO(tzh_magic);
 		DO(tzh_version);
 		DO(tzh_reserved);
 		DO(tzh_ttisutcnt);
 		DO(tzh_ttisstdcnt);
 		DO(tzh_leapcnt);
 		DO(tzh_timecnt);
 		DO(tzh_typecnt);
 		DO(tzh_charcnt);
 #undef DO
 		if (pass == 1 && !want_bloat()) {
 		  /* Output a minimal data block with just one time type.  */
 		  puttzcode(0, fp);	/* utoff */
 		  putc(0, fp);		/* dst */
 		  putc(0, fp);		/* index of abbreviation */
 		  putc(0, fp);		/* empty-string abbreviation */
 		  continue;
 		}
 
 		/* Output a LO_TIME transition if needed; see limitrange.
 		   But do not go below the minimum representable value
 		   for this pass.  */
 		lo = pass == 1 && lo_time < ZIC32_MIN ? ZIC32_MIN : lo_time;
 
 		if (0 <= pretranstype)
 		  puttzcodepass(lo, fp, pass);
 		for (i = thistimei; i < thistimelim; ++i) {
 		  puttzcodepass(ats[i], fp, pass);
 		}
 		if (hicut)
 		  puttzcodepass(hi_time + 1, fp, pass);
 		if (0 <= pretranstype)
 		  putc(typemap[pretranstype], fp);
 		for (i = thistimei; i < thistimelim; i++)
 		  putc(typemap[types[i]], fp);
 		if (hicut)
 		  putc(typemap[unspecifiedtype], fp);
 
 		for (i = old0; i < typecnt; i++) {
 		  int h = (i == old0 ? thisdefaulttype
 			   : i == thisdefaulttype ? old0 : i);
 		  if (!omittype[h]) {
 		    puttzcode(utoffs[h], fp);
 		    putc(isdsts[h], fp);
 		    putc(indmap[desigidx[h]], fp);
 		  }
 		}
 		if (thischarcnt != 0)
 			fwrite(thischars, sizeof thischars[0],
 				      thischarcnt, fp);
 		thisleaplim = thisleapi + thisleapcnt;
 		for (i = thisleapi; i < thisleaplim; ++i) {
 			register zic_t	todo;
 
 			if (roll[i]) {
 				if (timecnt == 0 || trans[i] < ats[0]) {
 					j = 0;
 					while (isdsts[j])
 						if (++j >= typecnt) {
 							j = 0;
 							break;
 						}
 				} else {
 					j = 1;
 					while (j < timecnt &&
 						trans[i] >= ats[j])
 							++j;
 					j = types[j - 1];
 				}
 				todo = tadd(trans[i], -utoffs[j]);
 			} else	todo = trans[i];
 			puttzcodepass(todo, fp, pass);
 			puttzcode(corr[i], fp);
 		}
 		if (thisleapexpiry) {
 		  /* Append a no-op leap correction indicating when the leap
 		     second table expires.  Although this does not conform to
 		     Internet RFC 8536, most clients seem to accept this and
 		     the plan is to amend the RFC to allow this in version 4
 		     TZif files.  */
 		  puttzcodepass(leapexpires, fp, pass);
 		  puttzcode(thisleaplim ? corr[thisleaplim - 1] : 0, fp);
 		}
 		if (stdcnt != 0)
 		  for (i = old0; i < typecnt; i++)
 			if (!omittype[i])
 				putc(ttisstds[i], fp);
 		if (utcnt != 0)
 		  for (i = old0; i < typecnt; i++)
 			if (!omittype[i])
 				putc(ttisuts[i], fp);
 	}
 	fprintf(fp, "\n%s\n", string);
 	close_file(fp, directory, name, tempname);
 	if (chmod(tempname, mflag) < 0) {
 		fprintf(stderr, _("cannot change mode of %s to %03o"),
 		    tempname, (unsigned)mflag);
 		exit(EXIT_FAILURE);
 	}
 	if ((uflag != (uid_t)-1 || gflag != (gid_t)-1)
 	    && chown(tempname, uflag, gflag) < 0) {
 		fprintf(stderr, _("cannot change ownership of %s"), 
 		    tempname);
 		exit(EXIT_FAILURE);
 	}
 	rename_dest(tempname, name);
 	free(ats);
 }
 
 static char const *
 abbroffset(char *buf, zic_t offset)
 {
   char sign = '+';
   int seconds, minutes;
 
   if (offset < 0) {
     offset = -offset;
     sign = '-';
   }
 
   seconds = offset % SECSPERMIN;
   offset /= SECSPERMIN;
   minutes = offset % MINSPERHOUR;
   offset /= MINSPERHOUR;
   if (100 <= offset) {
     error(_("%%z UT offset magnitude exceeds 99:59:59"));
     return "%z";
   } else {
     char *p = buf;
     *p++ = sign;
     *p++ = '0' + offset / 10;
     *p++ = '0' + offset % 10;
     if (minutes | seconds) {
       *p++ = '0' + minutes / 10;
       *p++ = '0' + minutes % 10;
       if (seconds) {
 	*p++ = '0' + seconds / 10;
 	*p++ = '0' + seconds % 10;
       }
     }
     *p = '\0';
     return buf;
   }
 }
 
 static char const disable_percent_s[] = "";
 
 static ptrdiff_t
 doabbr(char *abbr, struct zone const *zp, char const *letters,
        bool isdst, zic_t save, bool doquotes)
 {
 	register char *	cp;
 	register char *	slashp;
 	ptrdiff_t len;
 	char const *format = zp->z_format;
 
 	slashp = strchr(format, '/');
 	if (slashp == NULL) {
 	  char letterbuf[PERCENT_Z_LEN_BOUND + 1];
 	  if (zp->z_format_specifier == 'z')
 	    letters = abbroffset(letterbuf, zp->z_stdoff + save);
 	  else if (!letters)
 	    letters = "%s";
 	  else if (letters == disable_percent_s)
 	    return 0;
 	  sprintf(abbr, format, letters);
 	} else if (isdst) {
 		strcpy(abbr, slashp + 1);
 	} else {
 		memcpy(abbr, format, slashp - format);
 		abbr[slashp - format] = '\0';
 	}
 	len = strlen(abbr);
 	if (!doquotes)
 		return len;
 	for (cp = abbr; is_alpha(*cp); cp++)
 		continue;
 	if (len > 0 && *cp == '\0')
 		return len;
 	abbr[len + 2] = '\0';
 	abbr[len + 1] = '>';
 	memmove(abbr + 1, abbr, len);
 	abbr[0] = '<';
 	return len + 2;
 }
 
 static void
 updateminmax(const zic_t x)
 {
 	if (min_year > x)
 		min_year = x;
 	if (max_year < x)
 		max_year = x;
 }
 
 static int
 stringoffset(char *result, zic_t offset)
 {
 	register int	hours;
 	register int	minutes;
 	register int	seconds;
 	bool negative = offset < 0;
 	int len = negative;
 
 	if (negative) {
 		offset = -offset;
 		result[0] = '-';
 	}
 	seconds = offset % SECSPERMIN;
 	offset /= SECSPERMIN;
 	minutes = offset % MINSPERHOUR;
 	offset /= MINSPERHOUR;
 	hours = offset;
 	if (hours >= HOURSPERDAY * DAYSPERWEEK) {
 		result[0] = '\0';
 		return 0;
 	}
 	len += sprintf(result + len, "%d", hours);
 	if (minutes != 0 || seconds != 0) {
 		len += sprintf(result + len, ":%02d", minutes);
 		if (seconds != 0)
 			len += sprintf(result + len, ":%02d", seconds);
 	}
 	return len;
 }
 
 static int
 stringrule(char *result, struct rule *const rp, zic_t save, zic_t stdoff)
 {
 	register zic_t	tod = rp->r_tod;
 	register int	compat = 0;
 
 	if (rp->r_dycode == DC_DOM) {
 		register int	month, total;
 
 		if (rp->r_dayofmonth == 29 && rp->r_month == TM_FEBRUARY)
 			return -1;
 		total = 0;
 		for (month = 0; month < rp->r_month; ++month)
 			total += len_months[0][month];
 		/* Omit the "J" in Jan and Feb, as that's shorter.  */
 		if (rp->r_month <= 1)
 		  result += sprintf(result, "%d", total + rp->r_dayofmonth - 1);
 		else
 		  result += sprintf(result, "J%d", total + rp->r_dayofmonth);
 	} else {
 		register int	week;
 		register int	wday = rp->r_wday;
 		register int	wdayoff;
 
 		if (rp->r_dycode == DC_DOWGEQ) {
 			wdayoff = (rp->r_dayofmonth - 1) % DAYSPERWEEK;
 			if (wdayoff)
 				compat = 2013;
 			wday -= wdayoff;
 			tod += wdayoff * SECSPERDAY;
 			week = 1 + (rp->r_dayofmonth - 1) / DAYSPERWEEK;
 		} else if (rp->r_dycode == DC_DOWLEQ) {
 			if (rp->r_dayofmonth == len_months[1][rp->r_month])
 				week = 5;
 			else {
 				wdayoff = rp->r_dayofmonth % DAYSPERWEEK;
 				if (wdayoff)
 					compat = 2013;
 				wday -= wdayoff;
 				tod += wdayoff * SECSPERDAY;
 				week = rp->r_dayofmonth / DAYSPERWEEK;
 			}
 		} else	return -1;	/* "cannot happen" */
 		if (wday < 0)
 			wday += DAYSPERWEEK;
 		result += sprintf(result, "M%d.%d.%d",
 				  rp->r_month + 1, week, wday);
 	}
 	if (rp->r_todisut)
 	  tod += stdoff;
 	if (rp->r_todisstd && !rp->r_isdst)
 	  tod += save;
 	if (tod != 2 * SECSPERMIN * MINSPERHOUR) {
 		*result++ = '/';
 		if (! stringoffset(result, tod))
 			return -1;
 		if (tod < 0) {
 			if (compat < 2013)
 				compat = 2013;
 		} else if (SECSPERDAY <= tod) {
 			if (compat < 1994)
 				compat = 1994;
 		}
 	}
 	return compat;
 }
 
 static int
 rule_cmp(struct rule const *a, struct rule const *b)
 {
 	if (!a)
 		return -!!b;
 	if (!b)
 		return 1;
 	if (a->r_hiyear != b->r_hiyear)
 		return a->r_hiyear < b->r_hiyear ? -1 : 1;
 	if (a->r_hiyear == ZIC_MAX)
 		return 0;
 	if (a->r_month - b->r_month != 0)
 		return a->r_month - b->r_month;
 	return a->r_dayofmonth - b->r_dayofmonth;
 }
 
 static int
 stringzone(char *result, struct zone const *zpfirst, ptrdiff_t zonecount)
 {
 	register const struct zone *	zp;
 	register struct rule *		rp;
 	register struct rule *		stdrp;
 	register struct rule *		dstrp;
 	register ptrdiff_t		i;
 	register int			compat = 0;
 	register int			c;
 	int				offsetlen;
 	struct rule			stdr, dstr;
 	ptrdiff_t len;
 	int dstcmp;
 	struct rule *lastrp[2] = { NULL, NULL };
 	struct zone zstr[2];
 	struct zone const *stdzp;
 	struct zone const *dstzp;
 
 	result[0] = '\0';
 
 	/* Internet RFC 8536 section 5.1 says to use an empty TZ string if
 	   future timestamps are truncated.  */
 	if (hi_time < max_time)
 	  return -1;
 
 	zp = zpfirst + zonecount - 1;
 	for (i = 0; i < zp->z_nrules; ++i) {
 		struct rule **last;
 		int cmp;
 		rp = &zp->z_rules[i];
 		last = &lastrp[rp->r_isdst];
 		cmp = rule_cmp(*last, rp);
 		if (cmp < 0)
 		  *last = rp;
 		else if (cmp == 0)
 		  return -1;
 	}
 	stdrp = lastrp[false];
 	dstrp = lastrp[true];
 	dstcmp = zp->z_nrules ? rule_cmp(dstrp, stdrp) : zp->z_isdst ? 1 : -1;
 	stdzp = dstzp = zp;
 
 	if (dstcmp < 0) {
 	  /* Standard time all year.  */
 	  dstrp = NULL;
 	} else if (0 < dstcmp) {
 	  /* DST all year.  Use an abbreviation like
 	     "XXX3EDT4,0/0,J365/23" for EDT (-04) all year.  */
 	  zic_t save = dstrp ? dstrp->r_save : zp->z_save;
 	  if (0 <= save)
 	    {
 	      /* Positive DST, the typical case for all-year DST.
 		 Fake a timezone with negative DST.  */
 	      stdzp = &zstr[0];
 	      dstzp = &zstr[1];
 	      zstr[0].z_stdoff = zp->z_stdoff + 2 * save;
 	      zstr[0].z_format = "XXX";  /* Any 3 letters will do.  */
 	      zstr[0].z_format_specifier = 0;
 	      zstr[1].z_stdoff = zstr[0].z_stdoff;
 	      zstr[1].z_format = zp->z_format;
 	      zstr[1].z_format_specifier = zp->z_format_specifier;
 	    }
 	  dstr.r_month = TM_JANUARY;
 	  dstr.r_dycode = DC_DOM;
 	  dstr.r_dayofmonth = 1;
 	  dstr.r_tod = 0;
 	  dstr.r_todisstd = dstr.r_todisut = false;
 	  dstr.r_isdst = true;
 	  dstr.r_save = save < 0 ? save : -save;
 	  dstr.r_abbrvar = dstrp ? dstrp->r_abbrvar : NULL;
 	  stdr.r_month = TM_DECEMBER;
 	  stdr.r_dycode = DC_DOM;
 	  stdr.r_dayofmonth = 31;
 	  stdr.r_tod = SECSPERDAY + dstr.r_save;
 	  stdr.r_todisstd = stdr.r_todisut = false;
 	  stdr.r_isdst = false;
 	  stdr.r_save = 0;
 	  stdr.r_abbrvar = save < 0 && stdrp ? stdrp->r_abbrvar : NULL;
 	  dstrp = &dstr;
 	  stdrp = &stdr;
 	}
 	len = doabbr(result, stdzp, stdrp ? stdrp->r_abbrvar : NULL,
 		     false, 0, true);
 	offsetlen = stringoffset(result + len, - stdzp->z_stdoff);
 	if (! offsetlen) {
 		result[0] = '\0';
 		return -1;
 	}
 	len += offsetlen;
 	if (dstrp == NULL)
 		return compat;
 	len += doabbr(result + len, dstzp, dstrp->r_abbrvar,
 		      dstrp->r_isdst, dstrp->r_save, true);
 	if (dstrp->r_save != SECSPERMIN * MINSPERHOUR) {
 	  offsetlen = stringoffset(result + len,
 				   - (dstzp->z_stdoff + dstrp->r_save));
 	  if (! offsetlen) {
 	    result[0] = '\0';
 	    return -1;
 	  }
 	  len += offsetlen;
 	}
 	result[len++] = ',';
 	c = stringrule(result + len, dstrp, dstrp->r_save, stdzp->z_stdoff);
 	if (c < 0) {
 		result[0] = '\0';
 		return -1;
 	}
 	if (compat < c)
 		compat = c;
 	len += strlen(result + len);
 	result[len++] = ',';
 	c = stringrule(result + len, stdrp, dstrp->r_save, stdzp->z_stdoff);
 	if (c < 0) {
 		result[0] = '\0';
 		return -1;
 	}
 	if (compat < c)
 		compat = c;
 	return compat;
 }
 
 static void
 outzone(const struct zone *zpfirst, ptrdiff_t zonecount)
 {
 	register ptrdiff_t		i, j;
 	register zic_t			starttime, untiltime;
 	register bool			startttisstd;
 	register bool			startttisut;
 	register char *			startbuf;
 	register char *			ab;
 	register char *			envvar;
 	register int			max_abbr_len;
 	register int			max_envvar_len;
 	register bool			prodstic; /* all rules are min to max */
 	register int			compat;
 	register bool			do_extend;
 	register char			version;
 	ptrdiff_t lastatmax = -1;
 	zic_t max_year0;
 	int defaulttype = -1;
 
 	check_for_signal();
 
 	/* This cannot overflow; see FORMAT_LEN_GROWTH_BOUND.  */
 	max_abbr_len = 2 + max_format_len + max_abbrvar_len;
 	max_envvar_len = 2 * max_abbr_len + 5 * 9;
 
 	startbuf = emalloc(max_abbr_len + 1);
 	ab = emalloc(max_abbr_len + 1);
 	envvar = emalloc(max_envvar_len + 1);
 	INITIALIZE(untiltime);
 	INITIALIZE(starttime);
 	/*
 	** Now. . .finally. . .generate some useful data!
 	*/
 	timecnt = 0;
 	typecnt = 0;
 	charcnt = 0;
 	prodstic = zonecount == 1;
 	/*
 	** Thanks to Earl Chew
 	** for noting the need to unconditionally initialize startttisstd.
 	*/
 	startttisstd = false;
 	startttisut = false;
 	min_year = max_year = EPOCH_YEAR;
 	if (leapseen) {
 		updateminmax(leapminyear);
 		updateminmax(leapmaxyear + (leapmaxyear < ZIC_MAX));
 	}
 	for (i = 0; i < zonecount; ++i) {
 		struct zone const *zp = &zpfirst[i];
 		if (i < zonecount - 1)
 			updateminmax(zp->z_untilrule.r_loyear);
 		for (j = 0; j < zp->z_nrules; ++j) {
 			struct rule *rp = &zp->z_rules[j];
 			if (rp->r_lowasnum)
 				updateminmax(rp->r_loyear);
 			if (rp->r_hiwasnum)
 				updateminmax(rp->r_hiyear);
 			if (rp->r_lowasnum || rp->r_hiwasnum)
 				prodstic = false;
 		}
 	}
 	/*
 	** Generate lots of data if a rule can't cover all future times.
 	*/
 	compat = stringzone(envvar, zpfirst, zonecount);
 	version = compat < 2013 ? '2' : '3';
 	do_extend = compat < 0;
 	if (noise) {
 		if (!*envvar)
 			warning("%s %s",
 				_("no POSIX environment variable for zone"),
 				zpfirst->z_name);
 		else if (compat != 0) {
 			/* Circa-COMPAT clients, and earlier clients, might
 			   not work for this zone when given dates before
 			   1970 or after 2038.  */
 			warning(_("%s: pre-%d clients may mishandle"
 				  " distant timestamps"),
 				zpfirst->z_name, compat);
 		}
 	}
 	if (do_extend) {
 		/*
 		** Search through a couple of extra years past the obvious
 		** 400, to avoid edge cases.  For example, suppose a non-POSIX
 		** rule applies from 2012 onwards and has transitions in March
 		** and September, plus some one-off transitions in November
 		** 2013.  If zic looked only at the last 400 years, it would
 		** set max_year=2413, with the intent that the 400 years 2014
 		** through 2413 will be repeated.  The last transition listed
 		** in the tzfile would be in 2413-09, less than 400 years
 		** after the last one-off transition in 2013-11.  Two years
 		** might be overkill, but with the kind of edge cases
 		** available we're not sure that one year would suffice.
 		*/
 		enum { years_of_observations = YEARSPERREPEAT + 2 };
 
 		if (min_year >= ZIC_MIN + years_of_observations)
 			min_year -= years_of_observations;
 		else	min_year = ZIC_MIN;
 		if (max_year <= ZIC_MAX - years_of_observations)
 			max_year += years_of_observations;
 		else	max_year = ZIC_MAX;
 		/*
 		** Regardless of any of the above,
 		** for a "proDSTic" zone which specifies that its rules
 		** always have and always will be in effect,
 		** we only need one cycle to define the zone.
 		*/
 		if (prodstic) {
 			min_year = 1900;
 			max_year = min_year + years_of_observations;
 		}
 	}
 	max_year = max(max_year, (redundant_time / (SECSPERDAY * DAYSPERNYEAR)
 				  + EPOCH_YEAR + 1));
 	max_year0 = max_year;
 	if (want_bloat()) {
 	  /* For the benefit of older systems,
 	     generate data from 1900 through 2038.  */
 	  if (min_year > 1900)
 		min_year = 1900;
 	  if (max_year < 2038)
 		max_year = 2038;
 	}
 
 	if (min_time < lo_time || hi_time < max_time)
 	  unspecifiedtype = addtype(0, "-00", false, false, false);
 
 	for (i = 0; i < zonecount; ++i) {
 		struct rule *prevrp = NULL;
 		/*
 		** A guess that may well be corrected later.
 		*/
 		zic_t save = 0;
 		struct zone const *zp = &zpfirst[i];
 		bool usestart = i > 0 && (zp - 1)->z_untiltime > min_time;
 		bool useuntil = i < (zonecount - 1);
 		zic_t stdoff = zp->z_stdoff;
 		zic_t startoff = stdoff;
 		zic_t prevktime;
 		INITIALIZE(prevktime);
 		if (useuntil && zp->z_untiltime <= min_time)
 			continue;
 		eat(zp->z_filenum, zp->z_linenum);
 		*startbuf = '\0';
 		if (zp->z_nrules == 0) {
 			int type;
 			save = zp->z_save;
 			doabbr(startbuf, zp, NULL, zp->z_isdst, save, false);
 			type = addtype(oadd(zp->z_stdoff, save),
 				startbuf, zp->z_isdst, startttisstd,
 				startttisut);
 			if (usestart) {
 				addtt(starttime, type);
 				usestart = false;
 			} else
 				defaulttype = type;
 		} else {
 		  zic_t year;
 		  for (year = min_year; year <= max_year; ++year) {
 			if (useuntil && year > zp->z_untilrule.r_hiyear)
 				break;
 			/*
 			** Mark which rules to do in the current year.
 			** For those to do, calculate rpytime(rp, year);
 			** The former TYPE field was also considered here.
 			*/
 			for (j = 0; j < zp->z_nrules; ++j) {
 				zic_t one = 1;
 				zic_t y2038_boundary = one << 31;
 				struct rule *rp = &zp->z_rules[j];
 				eats(zp->z_filenum, zp->z_linenum,
 				     rp->r_filenum, rp->r_linenum);
 				rp->r_todo = year >= rp->r_loyear &&
 						year <= rp->r_hiyear;
 				if (rp->r_todo) {
 					rp->r_temp = rpytime(rp, year);
 					rp->r_todo
 					  = (rp->r_temp < y2038_boundary
 					     || year <= max_year0);
 				}
 			}
 			for ( ; ; ) {
 				register ptrdiff_t k;
 				register zic_t	jtime, ktime;
 				register zic_t	offset;
 				struct rule *rp;
 				int type;
 
 				INITIALIZE(ktime);
 				if (useuntil) {
 					/*
 					** Turn untiltime into UT
 					** assuming the current stdoff and
 					** save values.
 					*/
 					untiltime = zp->z_untiltime;
 					if (!zp->z_untilrule.r_todisut)
 						untiltime = tadd(untiltime,
 								 -stdoff);
 					if (!zp->z_untilrule.r_todisstd)
 						untiltime = tadd(untiltime,
 								 -save);
 				}
 				/*
 				** Find the rule (of those to do, if any)
 				** that takes effect earliest in the year.
 				*/
 				k = -1;
 				for (j = 0; j < zp->z_nrules; ++j) {
 					struct rule *r = &zp->z_rules[j];
 					if (!r->r_todo)
 						continue;
 					eats(zp->z_filenum, zp->z_linenum,
 					     r->r_filenum, r->r_linenum);
 					offset = r->r_todisut ? 0 : stdoff;
 					if (!r->r_todisstd)
 						offset = oadd(offset, save);
 					jtime = r->r_temp;
 					if (jtime == min_time ||
 						jtime == max_time)
 							continue;
 					jtime = tadd(jtime, -offset);
 					if (k < 0 || jtime < ktime) {
 						k = j;
 						ktime = jtime;
 					} else if (jtime == ktime) {
 					  char const *dup_rules_msg =
 					    _("two rules for same instant");
 					  eats(zp->z_filenum, zp->z_linenum,
 					       r->r_filenum, r->r_linenum);
 					  warning("%s", dup_rules_msg);
 					  r = &zp->z_rules[k];
 					  eats(zp->z_filenum, zp->z_linenum,
 					       r->r_filenum, r->r_linenum);
 					  error("%s", dup_rules_msg);
 					}
 				}
 				if (k < 0)
 					break;	/* go on to next year */
 				rp = &zp->z_rules[k];
 				rp->r_todo = false;
 				if (useuntil && ktime >= untiltime) {
 					if (!*startbuf
 					    && (oadd(zp->z_stdoff, rp->r_save)
 						== startoff))
 					  doabbr(startbuf, zp, rp->r_abbrvar,
 						 rp->r_isdst, rp->r_save,
 						 false);
 					break;
 				}
 				save = rp->r_save;
 				if (usestart && ktime == starttime)
 					usestart = false;
 				if (usestart) {
 					if (ktime < starttime) {
 						startoff = oadd(zp->z_stdoff,
 								save);
 						doabbr(startbuf, zp,
 							rp->r_abbrvar,
 							rp->r_isdst,
 							rp->r_save,
 							false);
 						continue;
 					}
 					if (*startbuf == '\0'
 					    && startoff == oadd(zp->z_stdoff,
 								save)) {
 							doabbr(startbuf,
 								zp,
 								rp->r_abbrvar,
 								rp->r_isdst,
 								rp->r_save,
 								false);
 					}
 				}
 				eats(zp->z_filenum, zp->z_linenum,
 				     rp->r_filenum, rp->r_linenum);
 				doabbr(ab, zp, rp->r_abbrvar,
 				       rp->r_isdst, rp->r_save, false);
 				offset = oadd(zp->z_stdoff, rp->r_save);
 				if (!want_bloat() && !useuntil && !do_extend
 				    && prevrp && lo_time <= prevktime
 				    && redundant_time <= ktime
 				    && rp->r_hiyear == ZIC_MAX
 				    && prevrp->r_hiyear == ZIC_MAX)
 				  break;
 				type = addtype(offset, ab, rp->r_isdst,
 					rp->r_todisstd, rp->r_todisut);
 				if (defaulttype < 0 && !rp->r_isdst)
 				  defaulttype = type;
 				if (rp->r_hiyear == ZIC_MAX
 				    && ! (0 <= lastatmax
 					  && ktime < attypes[lastatmax].at))
 				  lastatmax = timecnt;
 				addtt(ktime, type);
 				prevrp = rp;
 				prevktime = ktime;
 			}
 		  }
 		}
 		if (usestart) {
 			bool isdst = startoff != zp->z_stdoff;
 			if (*startbuf == '\0' && zp->z_format)
 			  doabbr(startbuf, zp, disable_percent_s,
 				 isdst, save, false);
 			eat(zp->z_filenum, zp->z_linenum);
 			if (*startbuf == '\0')
 error(_("can't determine time zone abbreviation to use just after until time"));
 			else {
 			  int type = addtype(startoff, startbuf, isdst,
 					     startttisstd, startttisut);
 			  if (defaulttype < 0 && !isdst)
 			    defaulttype = type;
 			  addtt(starttime, type);
 			}
 		}
 		/*
 		** Now we may get to set starttime for the next zone line.
 		*/
 		if (useuntil) {
 			startttisstd = zp->z_untilrule.r_todisstd;
 			startttisut = zp->z_untilrule.r_todisut;
 			starttime = zp->z_untiltime;
 			if (!startttisstd)
 			  starttime = tadd(starttime, -save);
 			if (!startttisut)
 			  starttime = tadd(starttime, -stdoff);
 		}
 	}
 	if (defaulttype < 0)
 	  defaulttype = 0;
 	if (0 <= lastatmax)
 	  attypes[lastatmax].dontmerge = true;
 	if (do_extend) {
 		/*
 		** If we're extending the explicitly listed observations
 		** for 400 years because we can't fill the POSIX-TZ field,
 		** check whether we actually ended up explicitly listing
 		** observations through that period.  If there aren't any
 		** near the end of the 400-year period, add a redundant
 		** one at the end of the final year, to make it clear
 		** that we are claiming to have definite knowledge of
 		** the lack of transitions up to that point.
 		*/
 		struct rule xr;
 		struct attype *lastat;
 		xr.r_month = TM_JANUARY;
 		xr.r_dycode = DC_DOM;
 		xr.r_dayofmonth = 1;
 		xr.r_tod = 0;
 		for (lastat = attypes, i = 1; i < timecnt; i++)
 			if (attypes[i].at > lastat->at)
 				lastat = &attypes[i];
 		if (!lastat || lastat->at < rpytime(&xr, max_year - 1)) {
 			addtt(rpytime(&xr, max_year + 1),
 			      lastat ? lastat->type : defaulttype);
 			attypes[timecnt - 1].dontmerge = true;
 		}
 	}
 	writezone(zpfirst->z_name, envvar, version, defaulttype);
 	free(startbuf);
 	free(ab);
 	free(envvar);
 }
 
 static void
 addtt(zic_t starttime, int type)
 {
 	attypes = growalloc(attypes, sizeof *attypes, timecnt, &timecnt_alloc);
 	attypes[timecnt].at = starttime;
 	attypes[timecnt].dontmerge = false;
 	attypes[timecnt].type = type;
 	++timecnt;
 }
 
 static int
 addtype(zic_t utoff, char const *abbr, bool isdst, bool ttisstd, bool ttisut)
 {
 	register int	i, j;
 
 	if (! (-1L - 2147483647L <= utoff && utoff <= 2147483647L)) {
 		error(_("UT offset out of range"));
 		exit(EXIT_FAILURE);
 	}
 	if (!want_bloat())
 	  ttisstd = ttisut = false;
 
 	for (j = 0; j < charcnt; ++j)
 		if (strcmp(&chars[j], abbr) == 0)
 			break;
 	if (j == charcnt)
 		newabbr(abbr);
 	else {
 	  /* If there's already an entry, return its index.  */
 	  for (i = 0; i < typecnt; i++)
 	    if (utoff == utoffs[i] && isdst == isdsts[i] && j == desigidx[i]
 		&& ttisstd == ttisstds[i] && ttisut == ttisuts[i])
 	      return i;
 	}
 	/*
 	** There isn't one; add a new one, unless there are already too
 	** many.
 	*/
 	if (typecnt >= TZ_MAX_TYPES) {
 		error(_("too many local time types"));
 		exit(EXIT_FAILURE);
 	}
 	i = typecnt++;
 	utoffs[i] = utoff;
 	isdsts[i] = isdst;
 	ttisstds[i] = ttisstd;
 	ttisuts[i] = ttisut;
 	desigidx[i] = j;
 	return i;
 }
 
 static void
 leapadd(zic_t t, int correction, int rolling)
 {
 	register int i;
 
 	if (TZ_MAX_LEAPS <= leapcnt) {
 		error(_("too many leap seconds"));
 		exit(EXIT_FAILURE);
 	}
 	if (rolling && (lo_time != min_time || hi_time != max_time)) {
 	  error(_("Rolling leap seconds not supported with -r"));
 	  exit(EXIT_FAILURE);
 	}
 	for (i = 0; i < leapcnt; ++i)
 		if (t <= trans[i])
 			break;
 	memmove(&trans[i + 1], &trans[i], (leapcnt - i) * sizeof *trans);
 	memmove(&corr[i + 1], &corr[i], (leapcnt - i) * sizeof *corr);
 	memmove(&roll[i + 1], &roll[i], (leapcnt - i) * sizeof *roll);
 	trans[i] = t;
 	corr[i] = correction;
 	roll[i] = rolling;
 	++leapcnt;
 }
 
 static void
 adjleap(void)
 {
 	register int	i;
 	register zic_t	last = 0;
 	register zic_t	prevtrans = 0;
 
 	/*
 	** propagate leap seconds forward
 	*/
 	for (i = 0; i < leapcnt; ++i) {
 		if (trans[i] - prevtrans < 28 * SECSPERDAY) {
 		  error(_("Leap seconds too close together"));
 		  exit(EXIT_FAILURE);
 		}
 		prevtrans = trans[i];
 		trans[i] = tadd(trans[i], last);
 		last = corr[i] += last;
 	}
 
 	if (0 <= leapexpires) {
 	  leapexpires = oadd(leapexpires, last);
 	  if (! (leapcnt == 0 || (trans[leapcnt - 1] < leapexpires))) {
 	    error(_("last Leap time does not precede Expires time"));
 	    exit(EXIT_FAILURE);
 	  }
 	}
 }
 
 /* Is A a space character in the C locale?  */
 static bool
 is_space(char a)
 {
 	switch (a) {
 	  default:
 		return false;
 	  case ' ': case '\f': case '\n': case '\r': case '\t': case '\v':
 		return true;
 	}
 }
 
 /* Is A an alphabetic character in the C locale?  */
 static bool
 is_alpha(char a)
 {
 	switch (a) {
 	  default:
 		return false;
 	  case 'A': case 'B': case 'C': case 'D': case 'E': case 'F': case 'G':
 	  case 'H': case 'I': case 'J': case 'K': case 'L': case 'M': case 'N':
 	  case 'O': case 'P': case 'Q': case 'R': case 'S': case 'T': case 'U':
 	  case 'V': case 'W': case 'X': case 'Y': case 'Z':
 	  case 'a': case 'b': case 'c': case 'd': case 'e': case 'f': case 'g':
 	  case 'h': case 'i': case 'j': case 'k': case 'l': case 'm': case 'n':
 	  case 'o': case 'p': case 'q': case 'r': case 's': case 't': case 'u':
 	  case 'v': case 'w': case 'x': case 'y': case 'z':
 		return true;
 	}
 }
 
 /* If A is an uppercase character in the C locale, return its lowercase
    counterpart.  Otherwise, return A.  */
 static char
 lowerit(char a)
 {
 	switch (a) {
 	  default: return a;
 	  case 'A': return 'a'; case 'B': return 'b'; case 'C': return 'c';
 	  case 'D': return 'd'; case 'E': return 'e'; case 'F': return 'f';
 	  case 'G': return 'g'; case 'H': return 'h'; case 'I': return 'i';
 	  case 'J': return 'j'; case 'K': return 'k'; case 'L': return 'l';
 	  case 'M': return 'm'; case 'N': return 'n'; case 'O': return 'o';
 	  case 'P': return 'p'; case 'Q': return 'q'; case 'R': return 'r';
 	  case 'S': return 's'; case 'T': return 't'; case 'U': return 'u';
 	  case 'V': return 'v'; case 'W': return 'w'; case 'X': return 'x';
 	  case 'Y': return 'y'; case 'Z': return 'z';
 	}
 }
 
 /* case-insensitive equality */
-static ATTRIBUTE_REPRODUCIBLE bool
+ATTRIBUTE_REPRODUCIBLE static bool
 ciequal(register const char *ap, register const char *bp)
 {
 	while (lowerit(*ap) == lowerit(*bp++))
 		if (*ap++ == '\0')
 			return true;
 	return false;
 }
 
-static ATTRIBUTE_REPRODUCIBLE bool
+ATTRIBUTE_REPRODUCIBLE static bool
 itsabbr(register const char *abbr, register const char *word)
 {
 	if (lowerit(*abbr) != lowerit(*word))
 		return false;
 	++word;
 	while (*++abbr != '\0')
 		do {
 			if (*word == '\0')
 				return false;
 		} while (lowerit(*word++) != lowerit(*abbr));
 	return true;
 }
 
 /* Return true if ABBR is an initial prefix of WORD, ignoring ASCII case.  */
 
-static ATTRIBUTE_REPRODUCIBLE bool
+ATTRIBUTE_REPRODUCIBLE static bool
 ciprefix(char const *abbr, char const *word)
 {
   do
     if (!*abbr)
       return true;
   while (lowerit(*abbr++) == lowerit(*word++));
 
   return false;
 }
 
 static const struct lookup *
 byword(const char *word, const struct lookup *table)
 {
 	register const struct lookup *	foundlp;
 	register const struct lookup *	lp;
 
 	if (word == NULL || table == NULL)
 		return NULL;
 
 	/* If TABLE is LASTS and the word starts with "last" followed
 	   by a non-'-', skip the "last" and look in WDAY_NAMES instead.
 	   Warn about any usage of the undocumented prefix "last-".  */
 	if (table == lasts && ciprefix("last", word) && word[4]) {
 	  if (word[4] == '-')
 	    warning(_("\"%s\" is undocumented; use \"last%s\" instead"),
 		    word, word + 5);
 	  else {
 	    word += 4;
 	    table = wday_names;
 	  }
 	}
 
 	/*
 	** Look for exact match.
 	*/
 	for (lp = table; lp->l_word != NULL; ++lp)
 		if (ciequal(word, lp->l_word))
 			return lp;
 	/*
 	** Look for inexact match.
 	*/
 	foundlp = NULL;
 	for (lp = table; lp->l_word != NULL; ++lp)
 		if (ciprefix(word, lp->l_word)) {
 			if (foundlp == NULL)
 				foundlp = lp;
 			else	return NULL;	/* multiple inexact matches */
 		}
 
 	if (foundlp && noise) {
 	  /* Warn about any backward-compatibility issue with pre-2017c zic.  */
 	  bool pre_2017c_match = false;
 	  for (lp = table; lp->l_word; lp++)
 	    if (itsabbr(word, lp->l_word)) {
 	      if (pre_2017c_match) {
 		warning(_("\"%s\" is ambiguous in pre-2017c zic"), word);
 		break;
 	      }
 	      pre_2017c_match = true;
 	    }
 	}
 
 	return foundlp;
 }
 
 static int
 getfields(char *cp, char **array, int arrayelts)
 {
 	register char *		dp;
 	register int		nsubs;
 
 	nsubs = 0;
 	for ( ; ; ) {
 		char *dstart;
 		while (is_space(*cp))
 				++cp;
 		if (*cp == '\0' || *cp == '#')
 			break;
 		dstart = dp = cp;
 		do {
 			if ((*dp = *cp++) != '"')
 				++dp;
 			else while ((*dp = *cp++) != '"')
 				if (*dp != '\0')
 					++dp;
 				else {
 				  error(_("Odd number of quotation marks"));
 				  exit(EXIT_FAILURE);
 				}
 		} while (*cp && *cp != '#' && !is_space(*cp));
 		if (is_space(*cp))
 			++cp;
 		*dp = '\0';
 		if (nsubs == arrayelts) {
 		  error(_("Too many input fields"));
 		  exit(EXIT_FAILURE);
 		}
 		array[nsubs++] = dstart + (*dstart == '-' && dp == dstart + 1);
 	}
 	return nsubs;
 }
 
-static ATTRIBUTE_NORETURN void
+ATTRIBUTE_NORETURN static void
 time_overflow(void)
 {
   error(_("time overflow"));
   exit(EXIT_FAILURE);
 }
 
-static ATTRIBUTE_REPRODUCIBLE zic_t
+ATTRIBUTE_REPRODUCIBLE static zic_t
 oadd(zic_t t1, zic_t t2)
 {
 #ifdef ckd_add
   zic_t sum;
   if (!ckd_add(&sum, t1, t2))
     return sum;
 #else
   if (t1 < 0 ? ZIC_MIN - t1 <= t2 : t2 <= ZIC_MAX - t1)
     return t1 + t2;
 #endif
   time_overflow();
 }
 
-static ATTRIBUTE_REPRODUCIBLE zic_t
+ATTRIBUTE_REPRODUCIBLE static zic_t
 tadd(zic_t t1, zic_t t2)
 {
 #ifdef ckd_add
   zic_t sum;
   if (!ckd_add(&sum, t1, t2) && min_time <= sum && sum <= max_time)
     return sum;
 #else
   if (t1 < 0 ? min_time - t1 <= t2 : t2 <= max_time - t1)
     return t1 + t2;
 #endif
   if (t1 == min_time || t1 == max_time)
     return t1;
   time_overflow();
 }
 
 /*
 ** Given a rule, and a year, compute the date (in seconds since January 1,
 ** 1970, 00:00 LOCAL time) in that year that the rule refers to.
 */
 
 static zic_t
 rpytime(const struct rule *rp, zic_t wantedy)
 {
 	register int	m, i;
 	register zic_t	dayoff;			/* with a nod to Margaret O. */
 	register zic_t	t, y;
 	int yrem;
 
 	if (wantedy == ZIC_MIN)
 		return min_time;
 	if (wantedy == ZIC_MAX)
 		return max_time;
 	m = TM_JANUARY;
 	y = EPOCH_YEAR;
 
 	/* dayoff = floor((wantedy - y) / YEARSPERREPEAT) * DAYSPERREPEAT,
 	   sans overflow.  */
 	yrem = wantedy % YEARSPERREPEAT - y % YEARSPERREPEAT;
 	dayoff = ((wantedy / YEARSPERREPEAT - y / YEARSPERREPEAT
 		   + yrem / YEARSPERREPEAT - (yrem % YEARSPERREPEAT < 0))
 		  * DAYSPERREPEAT);
 	/* wantedy = y + ((wantedy - y) mod YEARSPERREPEAT), sans overflow.  */
 	wantedy = y + (yrem + 2 * YEARSPERREPEAT) % YEARSPERREPEAT;
 
 	while (wantedy != y) {
 		i = len_years[isleap(y)];
 		dayoff = oadd(dayoff, i);
 		y++;
 	}
 	while (m != rp->r_month) {
 		i = len_months[isleap(y)][m];
 		dayoff = oadd(dayoff, i);
 		++m;
 	}
 	i = rp->r_dayofmonth;
 	if (m == TM_FEBRUARY && i == 29 && !isleap(y)) {
 		if (rp->r_dycode == DC_DOWLEQ)
 			--i;
 		else {
 			error(_("use of 2/29 in non leap-year"));
 			exit(EXIT_FAILURE);
 		}
 	}
 	--i;
 	dayoff = oadd(dayoff, i);
 	if (rp->r_dycode == DC_DOWGEQ || rp->r_dycode == DC_DOWLEQ) {
 		/*
 		** Don't trust mod of negative numbers.
 		*/
 		zic_t wday = ((EPOCH_WDAY + dayoff % DAYSPERWEEK + DAYSPERWEEK)
 			      % DAYSPERWEEK);
 		while (wday != rp->r_wday)
 			if (rp->r_dycode == DC_DOWGEQ) {
 				dayoff = oadd(dayoff, 1);
 				if (++wday >= DAYSPERWEEK)
 					wday = 0;
 				++i;
 			} else {
 				dayoff = oadd(dayoff, -1);
 				if (--wday < 0)
 					wday = DAYSPERWEEK - 1;
 				--i;
 			}
 		if (i < 0 || i >= len_months[isleap(y)][m]) {
 			if (noise)
 				warning(_("rule goes past start/end of month; \
 will not work with pre-2004 versions of zic"));
 		}
 	}
 	if (dayoff < min_time / SECSPERDAY)
 		return min_time;
 	if (dayoff > max_time / SECSPERDAY)
 		return max_time;
 	t = (zic_t) dayoff * SECSPERDAY;
 	return tadd(t, rp->r_tod);
 }
 
 static void
 newabbr(const char *string)
 {
 	register int	i;
 
 	if (strcmp(string, GRANDPARENTED) != 0) {
 		register const char *	cp;
 		const char *		mp;
 
 		cp = string;
 		mp = NULL;
 		while (is_alpha(*cp) || ('0' <= *cp && *cp <= '9')
 		       || *cp == '-' || *cp == '+')
 				++cp;
 		if (noise && cp - string < 3)
 		  mp = _("time zone abbreviation has fewer than 3 characters");
 		if (cp - string > ZIC_MAX_ABBR_LEN_WO_WARN)
 		  mp = _("time zone abbreviation has too many characters");
 		if (*cp != '\0')
 mp = _("time zone abbreviation differs from POSIX standard");
 		if (mp != NULL)
 			warning("%s (%s)", mp, string);
 	}
 	i = strlen(string) + 1;
 	if (charcnt + i > TZ_MAX_CHARS) {
 		error(_("too many, or too long, time zone abbreviations"));
 		exit(EXIT_FAILURE);
 	}
 	strcpy(&chars[charcnt], string);
 	charcnt += i;
 }
 
 /* Ensure that the directories of ARGNAME exist, by making any missing
    ones.  If ANCESTORS, do this only for ARGNAME's ancestors; otherwise,
    do it for ARGNAME too.  Exit with failure if there is trouble.
    Do not consider an existing file to be trouble.  */
 static void
 mkdirs(char const *argname, bool ancestors)
 {
 	/*
 	 * If -D was specified, do not create directories.  A subsequent
 	 * file operation will fail and produce an appropriate error
 	 * message.
 	 */
 	if (Dflag)
 		return;
 
 	char *name = estrdup(argname);
 	char *cp = name;
 
 	/* On MS-Windows systems, do not worry about drive letters or
 	   backslashes, as this should suffice in practice.  Time zone
 	   names do not use drive letters and backslashes.  If the -d
 	   option of zic does not name an already-existing directory,
 	   it can use slashes to separate the already-existing
 	   ancestor prefix from the to-be-created subdirectories.  */
 
 	/* Do not mkdir a root directory, as it must exist.  */
 	while (*cp == '/')
 	  cp++;
 
 	while (cp && ((cp = strchr(cp, '/')) || !ancestors)) {
 		if (cp)
 		  *cp = '\0';
 		/*
 		** Try to create it.  It's OK if creation fails because
 		** the directory already exists, perhaps because some
 		** other process just created it.  For simplicity do
 		** not check first whether it already exists, as that
 		** is checked anyway if the mkdir fails.
 		*/
 		if (mkdir(name, MKDIR_UMASK) != 0) {
 			/* Do not report an error if err == EEXIST, because
 			   some other process might have made the directory
 			   in the meantime.  Likewise for ENOSYS, because
 			   Solaris 10 mkdir fails with ENOSYS if the
 			   directory is an automounted mount point.
 			   Likewise for EACCES, since mkdir can fail
 			   with EACCES merely because the parent directory
 			   is unwritable.  Likewise for most other error
 			   numbers.  */
 			int err = errno;
 			if (err == ELOOP || err == ENAMETOOLONG
 			    || err == ENOENT || err == ENOTDIR) {
 				error(_("%s: Can't create directory %s: %s"),
 				      progname, name, strerror(err));
 				exit(EXIT_FAILURE);
 			}
 		}
 		if (cp)
 		  *cp++ = '/';
 	}
 	free(name);
 }
 
 #include 
 #include 
 
 static void
 setgroup(gid_t *flag, const char *name)
 {
 	struct group *gr;
 
 	if (*flag != (gid_t)-1) {
 		fprintf(stderr, _("multiple -g flags specified"));
 		exit(EXIT_FAILURE);
 	}
 
 	gr = getgrnam(name);
 	if (gr == 0) {
 		char *ep;
 		unsigned long ul;
 
 		ul = strtoul(name, &ep, 10);
 		if (ul == (unsigned long)(gid_t)ul && *ep == '\0') {
 			*flag = ul;
 			return;
 		}
 		fprintf(stderr, _("group `%s' not found"), name);
 		exit(EXIT_FAILURE);
 	}
 	*flag = gr->gr_gid;
 }
 
 static void
 setuser(uid_t *flag, const char *name)
 {
 	struct passwd *pw;
 
 	if (*flag != (gid_t)-1) {
 		fprintf(stderr, _("multiple -u flags specified"));
 		exit(EXIT_FAILURE);
 	}
 
 	pw = getpwnam(name);
 	if (pw == 0) {
 		char *ep;
 		unsigned long ul;
 
 		ul = strtoul(name, &ep, 10);
 		if (ul == (unsigned long)(gid_t)ul && *ep == '\0') {
 			*flag = ul;
 			return;
 		}
 		fprintf(stderr, _("user `%s' not found"), name);
 		exit(EXIT_FAILURE);
 	}
 	*flag = pw->pw_uid;
 }
 
 /*
 ** UNIX was a registered trademark of The Open Group in 2003.
 */
diff --git a/lib/libc/stdtime/Symbol.map b/lib/libc/stdtime/Symbol.map
index bc113c650d2f..acdd3bbb89b4 100644
--- a/lib/libc/stdtime/Symbol.map
+++ b/lib/libc/stdtime/Symbol.map
@@ -1,34 +1,35 @@
 /*
  */
 
 FBSD_1.0 {
 	_time32_to_time;
 	_time_to_time32;
 	_time64_to_time;
 	_time_to_time64;
 	_time_to_long;
 	_long_to_time;
 	_time_to_int;
 	_int_to_time;
 	strptime;
 	strftime;
 	tzname;
 	tzsetwall;
 	tzset;
 	localtime;
 	localtime_r;
 	gmtime;
 	gmtime_r;
 	offtime;
+	offtime_r;
 	ctime;
 	ctime_r;
 	mktime;
 	timelocal;
 	timegm;
 	timeoff;
 	time2posix;
 	posix2time;
 	difftime;
 	asctime_r;
 	asctime;
 };