IANA 2023d

tz/.gitignore

@@ -18,6 +18,7 @@ ChangeLog
 check_*
 date
 leapseconds
+tzdir.h
 tzselect
 version
 version.h

tz/NEWS

@@ -1,5 +1,109 @@
 News for the tz database
 
+Release 2023d - 2023-12-21 20:02:24 -0800
+
+  Briefly:
+    Ittoqqortoormiit, Greenland changes time zones on 2024-03-31.
+    Vostok, Antarctica changed time zones on 2023-12-18.
+    Casey, Antarctica changed time zones five times since 2020.
+    Code and data fixes for Palestine timestamps starting in 2072.
+    A new data file zonenow.tab for timestamps starting now.
+
+  Changes to future timestamps
+
+    Ittoqqortoormiit, Greenland (America/Scoresbysund) joins most of
+    the rest of Greenland's timekeeping practice on 2024-03-31, by
+    changing its time zone from -01/+00 to -02/-01 at the same moment
+    as the spring-forward transition.  Its clocks will therefore not
+    spring forward as previously scheduled.  The time zone change
+    reverts to its common practice before 1981.
+
+    Fix predictions for DST transitions in Palestine in 2072-2075,
+    correcting a typo introduced in 2023a.
+
+  Changes to past and future timestamps
+
+    Vostok, Antarctica changed to +05 on 2023-12-18.  It had been at
+    +07 (not +06) for years.  (Thanks to Zakhary V. Akulov.)
+
+    Change data for Casey, Antarctica to agree with timeanddate.com,
+    by adding five time zone changes since 2020.  Casey is now at +08
+    instead of +11.
+
+  Changes to past tm_isdst flags
+
+    Much of Greenland, represented by America/Nuuk, changed its
+    standard time from -03 to -02 on 2023-03-25, not on 2023-10-28.
+    This does not affect UTC offsets, only the tm_isdst flag.
+    (Thanks to Thomas M. Steenholdt.)
+
+  New data file
+
+    A new data file zonenow.tab helps configure applications that use
+    timestamps dated from now on.  This simplifies configuration,
+    since users choose from a smaller Zone set.  The file's format is
+    experimental and subject to change.
+
+  Changes to code
+
+    localtime.c no longer mishandles TZif files that contain a single
+    transition into a DST regime.  Previously, it incorrectly assumed
+    DST was in effect before the transition too.  (Thanks to Alois
+    Treindl for debugging help.)
+
+    localtime.c's timeoff no longer collides with OpenBSD 7.4.
+
+    The C code now uses _Generic only if __STDC_VERSION__ says the
+    compiler is C11 or later.
+
+    tzselect now optionally reads zonenow.tab, to simplify when
+    configuring only for timestamps dated from now on.
+
+    tzselect no longer creates temporary files.
+
+    tzselect no longer mishandles the following:
+
+      Spaces and most other special characters in BUGEMAIL, PACKAGE,
+      TZDIR, and VERSION.
+
+      TZ strings when using mawk 1.4.3, which mishandles regular
+      expressions of the form /X{2,}/.
+
+      ISO 6709 coordinates when using an awk that lacks the GNU
+      extension of newlines in -v option-arguments.
+
+      Non UTF-8 locales when using an iconv command that lacks the GNU
+      //TRANSLIT extension.
+
+    zic no longer mishandles data for Palestine after the year 2075.
+    Previously, it incorrectly omitted post-2075 transitions that are
+    predicted for just before and just after Ramadan.  (Thanks to Ken
+    Murchison for debugging help.)
+
+    zic now works again on Linux 2.6.16 and 2.6.17 (2006).
+    (Problem reported by Rune Torgersen.)
+
+  Changes to build procedure
+
+    The Makefile is now more compatible with POSIX:
+     * It no longer defines AR, CC, CFLAGS, LDFLAGS, and SHELL.
+     * It no longer uses its own 'cc' in place of CC.
+     * It now uses ARFLAGS, with default specified by POSIX.
+     * It does not use LFLAGS incompatibly with POSIX.
+     * It uses the special .POSIX target.
+     * It quotes special characters more carefully.
+     * It no longer mishandles builds in an ISO 8859 locale.
+    Due to the CC changes, TZDIR is now #defined in a file tzfile.h
+    built by 'make', not in a $(CC) -D option.  Also, TZDEFAULT is
+    now treated like TZDIR as they have similar roles.
+
+  Changes to commentary
+
+     Limitations and hazards of the optional support for obsolescent
+     C89 platforms are documented better, along with a tentative
+     schedule for removing this support.
+
+
 Release 2023c - 2023-03-28 12:42:14 -0700
 
   Changes to past and future timestamps
@@ -76,11 +180,14 @@ Release 2023a - 2023-03-22 12:39:33 -0700
     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 by default is now designed for C99 or later.  To build on
+    a mostly-C89 platform, compile with -DPORT_TO_C89; this should
+    work on C89 platforms that also support C99 'long long' and
+    perhaps a few other extensions to C89.  To support C89 callers of
+    tzcode's library, compile with -DSUPPORT_C89; however, this could
+    trigger latent bugs in C99-or-later callers.  The two new macros
+    are transitional aids planned to be removed in a future version
+    (say, in 2029), 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.
@@ -723,6 +830,8 @@ Release 2021b - 2021-09-24 16:23:00 -0700
     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.
+    The old-format "#expires" comments are now treated solely as
+    comments and have no effect on the TZif files.
 
     zic -L LEAPFILE -r @LO no longer generates an invalid TZif file
     that omits leap second information for the range LO..B when LO
@@ -4302,7 +4411,7 @@ Release 2012j - 2012-11-12 18:34:49 -0800
   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
+  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,
@@ -4467,8 +4576,8 @@ 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)
+  made in all 4 Ukrainian zones, rather than just Europe/Kiev
+  (again, thanks to Tim Parenti, and also Denys Gavrysh).
 
   In addition, I added Europe/Tiraspol to zone.tab.
 

tz/README

@@ -11,14 +11,17 @@ changes made by political bodies to time zone boundaries, UTC offsets,
 and daylight-saving rules.
 
 See <https://www.iana.org/time-zones/repository/tz-link.html> or the
-file tz-link.html for how to acquire the code and data.  Once acquired,
-read the comments in the file 'Makefile' and make any changes needed
-to make things right for your system, especially if you are using some
-platform other than GNU/Linux.  Then run the following commands,
-substituting your desired installation directory for "$HOME/tzdir":
-
-	make TOPDIR=$HOME/tzdir install
-	$HOME/tzdir/usr/bin/zdump -v America/Los_Angeles
+file tz-link.html for how to acquire the code and data.
+
+Once acquired, read the leading comments in the file "Makefile"
+and make any changes needed to make things right for your system,
+especially when using a platform other than current GNU/Linux.
+
+Then run the following commands, substituting your desired
+installation directory for "$HOME/tzdir":
+
+	make TOPDIR="$HOME/tzdir" install
+	"$HOME/tzdir/usr/bin/zdump" -v America/Los_Angeles
 
 See the file tz-how-to.html for examples of how to read the data files.
 

tz/africa

@@ -285,13 +285,6 @@ Rule	Egypt	2007	only	-	Sep	Thu>=1	24:00	0	-
 # reproduced by other (more accessible) sites[, e.g.,]...
 # http://elgornal.net/news/news.aspx?id=4699258
 
-# From Paul Eggert (2014-06-04):
-# Sarah El Deeb and Lee Keath of AP report that the Egyptian government says
-# the change is because of blackouts in Cairo, even though Ahram Online (cited
-# above) says DST had no affect on electricity consumption.  There is
-# no information about when DST will end this fall.  See:
-# http://abcnews.go.com/International/wireStory/el-sissi-pushes-egyptians-line-23614833
-
 # From Steffen Thorsen (2015-04-08):
 # Egypt will start DST on midnight after Thursday, April 30, 2015.
 # This is based on a law (no 35) from May 15, 2014 saying it starts the last

tz/antarctica

@@ -80,6 +80,11 @@
 # - 2018 Oct  7 4:00 - 2019 Mar 17 3:00 - 2019 Oct  4 3:00 - 2020 Mar  8 3:00
 # and now - 2020 Oct  4 0:01
 
+# From Paul Eggert (2023-12-20):
+# Transitions from 2021 on are taken from:
+# https://www.timeanddate.com/time/zone/antarctica/casey
+# retrieved at various dates.
+
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
 Zone Antarctica/Casey	 0	-	-00	1969
 			 8:00	-	+08	2009 Oct 18  2:00
@@ -93,7 +98,12 @@ Zone Antarctica/Casey	 0	-	-00	1969
 			 8:00	-	+08	2019 Oct  4  3:00
 			11:00	-	+11	2020 Mar  8  3:00
 			 8:00	-	+08	2020 Oct  4  0:01
-			11:00	-	+11
+			11:00	-	+11	2021 Mar 14  0:00
+			 8:00	-	+08	2021 Oct  3  0:01
+			11:00	-	+11	2022 Mar 13  0:00
+			 8:00	-	+08	2022 Oct  2  0:01
+			11:00	-	+11	2023 Mar  9  3:00
+			 8:00	-	+08
 Zone Antarctica/Davis	0	-	-00	1957 Jan 13
 			7:00	-	+07	1964 Nov
 			0	-	-00	1969 Feb
@@ -240,7 +250,50 @@ Zone Antarctica/Troll	0	-	-00	2005 Feb 12
 #	year-round from 1960/61 to 1992
 
 # Vostok, since 1957-12-16, temporarily closed 1994-02/1994-11
-# See Asia/Urumqi.
+# From Craig Mundell (1994-12-15):
+# http://quest.arc.nasa.gov/antarctica/QA/computers/Directions,Time,ZIP
+# Vostok, which is one of the Russian stations, is set on the same
+# time as Moscow, Russia.
+#
+# From Lee Hotz (2001-03-08):
+# I queried the folks at Columbia who spent the summer at Vostok and this is
+# what they had to say about time there:
+# "in the US Camp (East Camp) we have been on New Zealand (McMurdo)
+# time, which is 12 hours ahead of GMT. The Russian Station Vostok was
+# 6 hours behind that (although only 2 miles away, i.e. 6 hours ahead
+# of GMT). This is a time zone I think two hours east of Moscow. The
+# natural time zone is in between the two: 8 hours ahead of GMT."
+#
+# From Paul Eggert (2001-05-04):
+# This seems to be hopelessly confusing, so I asked Lee Hotz about it
+# in person.  He said that some Antarctic locations set their local
+# time so that noon is the warmest part of the day, and that this
+# changes during the year and does not necessarily correspond to mean
+# solar noon.  So the Vostok time might have been whatever the clocks
+# happened to be during their visit.  So we still don't really know what time
+# it is at Vostok.
+#
+# From Zakhary V. Akulov (2023-12-17 22:00:48 +0700):
+# ... from December, 18, 2023 00:00 by my decision the local time of
+# the Antarctic research base Vostok will correspond to UTC+5.
+# (2023-12-19): We constantly interact with Progress base, with company who
+# builds new wintering station, with sledge convoys, with aviation - they all
+# use UTC+5. Besides, difference between Moscow time is just 2 hours now, not 4.
+# (2023-12-19, in response to the question "Has local time at Vostok
+# been UTC+6 ever since 1957, or has it changed before?"): No. At least
+# since my antarctic career start, 10 years ago, Vostok base has UTC+7.
+# (In response to a 2023-12-18 question "from 02:00 to 00:00 today"): This.
+#
+# From Paul Eggert (2023-12-18):
+# For lack of better info, guess Vostok was at +07 from founding through today,
+# except when closed.
+
+# Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
+Zone Antarctica/Vostok	0	-	-00	1957 Dec 16
+			7:00	-	+07	1994 Feb
+			0	-	-00	1994 Nov
+			7:00	-	+07	2023 Dec 18  2:00
+			5:00	-	+05
 
 # S Africa - year-round bases
 # Marion Island, -4653+03752

tz/asia

@@ -655,7 +655,6 @@ Zone	Asia/Shanghai	8:05:43	-	LMT	1901
 			8:00	PRC	C%sT
 # Xinjiang time, used by many in western China; represented by Ürümqi / Ürümchi
 # / Wulumuqi.  (Please use Asia/Shanghai if you prefer Beijing time.)
-# Vostok base in Antarctica matches this since 1970.
 Zone	Asia/Urumqi	5:50:20	-	LMT	1928
 			6:00	-	+06
 
@@ -3427,6 +3426,9 @@ Zone	Asia/Karachi	4:28:12 -	LMT	1907
 # From Heba Hamad (2023-03-22):
 # ... summer time will begin in Palestine from Saturday 04-29-2023,
 # 02:00 AM by 60 minutes forward.
+# From Heba Hemad (2023-10-09):
+# ... winter time will begin in Palestine from Saturday 10-28-2023,
+# 02:00 AM by 60 minutes back.
 #
 # From Paul Eggert (2023-03-22):
 # For now, guess that spring and fall transitions will normally
@@ -3548,13 +3550,13 @@ Rule Palestine	2070	only	-	Oct	 4	2:00	0	-
 Rule Palestine	2071	only	-	Sep	19	2:00	0	-
 Rule Palestine	2072	only	-	Sep	10	2:00	0	-
 Rule Palestine	2072	only	-	Oct	15	2:00	1:00	S
+Rule Palestine	2072	max	-	Oct	Sat<=30	2:00	0	-
 Rule Palestine	2073	only	-	Sep	 2	2:00	0	-
 Rule Palestine	2073	only	-	Oct	 7	2:00	1:00	S
 Rule Palestine	2074	only	-	Aug	18	2:00	0	-
 Rule Palestine	2074	only	-	Sep	29	2:00	1:00	S
 Rule Palestine	2075	only	-	Aug	10	2:00	0	-
 Rule Palestine	2075	only	-	Sep	14	2:00	1:00	S
-Rule Palestine	2075	max	-	Oct	Sat<=30	2:00	0	-
 Rule Palestine	2076	only	-	Jul	25	2:00	0	-
 Rule Palestine	2076	only	-	Sep	 5	2:00	1:00	S
 Rule Palestine	2077	only	-	Jul	17	2:00	0	-

tz/australasia

@@ -391,8 +391,14 @@ Zone Antarctica/Macquarie 0	-	-00	1899 Nov
 # Please note that there will not be any daylight savings time change
 # in Fiji for 2022-2023....
 # https://www.facebook.com/FijianGovernment/posts/pfbid0mmWVTYmTibn66ybpFda75pDcf34SSpoSaskJW5gXwaKo5Sgc7273Q4fXWc6kQV6Hl
+
+# From Almaz Mingaleev (2023-10-06):
+# Cabinet approved the suspension of Daylight Saving and appropriate
+# legislative changes will be considered including the repeal of the
+# Daylight Saving Act 1998
+# https://www.fiji.gov.fj/Media-Centre/Speeches/English/CABINET-DECISIONS-3-OCTOBER-2023
 #
-# From Paul Eggert (2022-10-27):
+# From Paul Eggert (2023-10-06):
 # For now, assume DST is suspended indefinitely.
 
 # Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S

tz/backward

@@ -205,7 +205,6 @@ Link	America/Puerto_Rico	America/Tortola
 Link	Pacific/Port_Moresby	Antarctica/DumontDUrville
 Link	Pacific/Auckland	Antarctica/McMurdo
 Link	Asia/Riyadh		Antarctica/Syowa
-Link	Asia/Urumqi		Antarctica/Vostok
 Link	Europe/Berlin		Arctic/Longyearbyen
 Link	Asia/Riyadh		Asia/Aden
 Link	Asia/Qatar		Asia/Bahrain

tz/backzone

@@ -963,35 +963,6 @@ Link Antarctica/McMurdo Antarctica/South_Pole
 Zone Antarctica/Syowa	0	-	-00	1957 Jan 29
 			3:00	-	+03
 
-# Vostok, Antarctica
-#
-# Vostok, since 1957-12-16, temporarily closed 1994-02/1994-11
-# From Craig Mundell (1994-12-15):
-# http://quest.arc.nasa.gov/antarctica/QA/computers/Directions,Time,ZIP
-# Vostok, which is one of the Russian stations, is set on the same
-# time as Moscow, Russia.
-#
-# From Lee Hotz (2001-03-08):
-# I queried the folks at Columbia who spent the summer at Vostok and this is
-# what they had to say about time there:
-# "in the US Camp (East Camp) we have been on New Zealand (McMurdo)
-# time, which is 12 hours ahead of GMT. The Russian Station Vostok was
-# 6 hours behind that (although only 2 miles away, i.e. 6 hours ahead
-# of GMT). This is a time zone I think two hours east of Moscow. The
-# natural time zone is in between the two: 8 hours ahead of GMT."
-#
-# From Paul Eggert (2001-05-04):
-# This seems to be hopelessly confusing, so I asked Lee Hotz about it
-# in person.  He said that some Antarctic locations set their local
-# time so that noon is the warmest part of the day, and that this
-# changes during the year and does not necessarily correspond to mean
-# solar noon.  So the Vostok time might have been whatever the clocks
-# happened to be during their visit.  So we still don't really know what time
-# it is at Vostok.  But we'll guess +06.
-#
-Zone Antarctica/Vostok	0	-	-00	1957 Dec 16
-			6:00	-	+06
-
 # Yemen
 # Milne says 2:59:54 was the meridian of the saluting battery at Aden,
 # and that Yemen was at 1:55:56, the meridian of the Hagia Sophia.