diff --git a/contrib/tzcode/stdtime/ctime.3 b/contrib/tzcode/stdtime/ctime.3
--- a/contrib/tzcode/stdtime/ctime.3
+++ b/contrib/tzcode/stdtime/ctime.3
@@ -279,6 +279,14 @@
 long tm_gmtoff;	/* offset from UTC in seconds */
 .Ed
 .Pp
+The field
+.Fa tm_sec
+range of 0-60 seconds allows for positive and negative leap seconds.
+.Pp
+The field
+.Fa tm_yday
+range of 0-365 days allows for leap years.
+.Pp
 The
 field
 .Fa tm_isdst