IANA 2024a

tz/Makefile

@@ -53,7 +53,7 @@ DATAFORM=		main
 
 LOCALTIME=	Factory
 
-# The POSIXRULES macro controls interpretation of POSIX-like TZ
+# The POSIXRULES macro controls interpretation of POSIX-2017.1-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 # Any other value for POSIXRULES is obsolete and should not be relied on, as:
@@ -274,7 +274,7 @@ LDLIBS=
 #  -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 for POSIX-style TZ strings lacking them,
+#	DST transitions for POSIX.1-2017-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.
@@ -340,9 +340,10 @@ GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \
 # 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.
+# and define NO_TM_ZONE to suppress any guessing.
+# Although these two fields are not required by POSIX.1-2017,
+# POSIX 202x/D4 requires 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
@@ -352,7 +353,7 @@ GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \
 # #	-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.
+# # to the "CFLAGS=" line.  "tzname" is required by POSIX.1-1988 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,
@@ -362,8 +363,8 @@ GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \
 # #	-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.
+# # to the "CFLAGS=" line; "timezone" and "daylight" are inspired by Unix
+# # Systems Group code and are required by POSIX.1-2008 and later (with XSI).
 # # If not defined, the code attempts to guess USG_COMPAT from other macros.
 # #
 # # To support the external variable "altzone", add
@@ -427,7 +428,7 @@ GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \
 
 # The name of a POSIX-like library archiver, its flags, C compiler,
 # linker flags, and 'make' utility.  Ordinarily the defaults suffice.
-# The commented-out values are the defaults specified by POSIX 202x/D3.
+# The commented-out values are the defaults specified by POSIX.1-202x/D4.
 #AR = ar
 #ARFLAGS = -rv
 #CC = c17
@@ -439,6 +440,12 @@ GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \
 
 LEAPSECONDS=
 
+# Where to fetch leap-seconds.list from.
+leaplist_URI = \
+  https://hpiers.obspm.fr/iers/bul/bulc/ntp/leap-seconds.list
+# The file is generated by the IERS Earth Orientation Centre, in Paris.
+leaplist_TZ = Europe/Paris
+
 # The zic command and its arguments.
 
 zic=		./zic
@@ -471,7 +478,8 @@ AWK=		awk
 # is typically nicer if it works.
 KSHELL=		/bin/bash
 
-# Name of curl <https://curl.haxx.se/>, used for HTML validation.
+# Name of curl <https://curl.haxx.se/>, used for HTML validation
+# and to fetch leap-seconds.list from upstream.
 CURL=		curl
 
 # Name of GNU Privacy Guard <https://gnupg.org/>, used to sign distributions.
@@ -718,6 +726,28 @@ leapseconds:	$(LEAP_DEPS)
 		  -f leapseconds.awk leap-seconds.list >$@.out
 		mv $@.out $@
 
+# Awk script to extract a Git-style author from leap-seconds.list comments.
+EXTRACT_AUTHOR = \
+  author_line { sub(/^.[[:space:]]*/, ""); \
+      sub(/:[[:space:]]*/, " <"); \
+      printf "%s>\n", $$0; \
+      success = 1; \
+      exit \
+  } \
+  /Questions or comments to:/ { author_line = 1 } \
+  END { exit !success }
+
+# Fetch leap-seconds.list from upstream.
+fetch-leap-seconds.list:
+		$(CURL) -OR $(leaplist_URI)
+
+# Fetch leap-seconds.list from upstream and commit it to the local repository.
+commit-leap-seconds.list: fetch-leap-seconds.list
+		author=$$($(AWK) '$(EXTRACT_AUTHOR)' leap-seconds.list) && \
+		date=$$(TZ=$(leaplist_TZ) stat -c%y leap-seconds.list) && \
+		git commit --author="$$author" --date="$$date" -m'make $@' \
+		  leap-seconds.list
+
 # Arguments to pass to submakes of install_data.
 # They can be overridden by later submake arguments.
 INSTALLARGS = \
@@ -1315,7 +1345,8 @@ zic.o:		private.h tzfile.h tzdir.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: clean clean_misc commit-leap-seconds.list dummy.zd
+.PHONY: fetch-leap-seconds.list force_tzs
 .PHONY: install install_data maintainer-clean names
 .PHONY: posix_only posix_right public
 .PHONY: rearguard_signatures rearguard_signatures_version

tz/NEWS

@@ -1,5 +1,73 @@
 News for the tz database
 
+Release 2024a - 2024-02-01 09:28:56 -0800
+
+  Briefly:
+    Kazakhstan unifies on UTC+5 beginning 2024-03-01.
+    Palestine springs forward a week later after Ramadan.
+    zic no longer pretends to support indefinite-past DST.
+    localtime no longer mishandles Ciudad Juárez in 2422.
+
+  Changes to future timestamps
+
+    Kazakhstan unifies on UTC+5.  This affects Asia/Almaty and
+    Asia/Qostanay which together represent the eastern portion of the
+    country that will transition from UTC+6 on 2024-03-01 at 00:00 to
+    join the western portion.  (Thanks to Zhanbolat Raimbekov.)
+
+    Palestine springs forward a week later than previously predicted
+    in 2024 and 2025.  (Thanks to Heba Hamad.)  Change spring-forward
+    predictions to the second Saturday after Ramadan, not the first;
+    this also affects other predictions starting in 2039.
+
+  Changes to past timestamps
+
+    Asia/Ho_Chi_Minh's 1955-07-01 transition occurred at 01:00
+    not 00:00.  (Thanks to Đoàn Trần Công Danh.)
+
+    From 1947 through 1949, Toronto's transitions occurred at 02:00
+    not 00:00.  (Thanks to Chris Walton.)
+
+    In 1911 Miquelon adopted standard time on June 15, not May 15.
+
+  Changes to code
+
+    The FROM and TO columns of Rule lines can no longer be "minimum"
+    or an abbreviation of "minimum", because TZif files do not support
+    DST rules that extend into the indefinite past - although these
+    rules were supported when TZif files had only 32-bit data, this
+    stopped working when 64-bit TZif files were introduced in 1995.
+    This should not be a problem for realistic data, since DST was
+    first used in the 20th century.  As a transition aid, FROM columns
+    like "minimum" are now diagnosed and then treated as if they were
+    the year 1900; this should suffice for TZif files on old systems
+    with only 32-bit time_t, and it is more compatible with bugs in
+    2023c-and-earlier localtime.c.  (Problem reported by Yoshito
+    Umaoka.)
+
+    localtime and related functions no longer mishandle some
+    timestamps that occur about 400 years after a switch to a time
+    zone with a DST schedule.  In 2023d data this problem was visible
+    for some timestamps in November 2422, November 2822, etc. in
+    America/Ciudad_Juarez.  (Problem reported by Gilmore Davidson.)
+
+    strftime %s now uses tm_gmtoff if available.  (Problem and draft
+    patch reported by Dag-Erling Smørgrav.)
+
+  Changes to build procedure
+
+    The leap-seconds.list file is now copied from the IERS instead of
+    from its downstream counterpart at NIST, as the IERS version is
+    now in the public domain too and tends to be more up-to-date.
+    (Thanks to Martin Burnicki for liaisoning with the IERS.)
+
+  Changes to documentation
+
+    The strftime man page documents which struct tm members affect
+    which conversion specs, and that tzset is called.  (Problems
+    reported by Robert Elz and Steve Summit.)
+
+
 Release 2023d - 2023-12-21 20:02:24 -0800
 
   Briefly:

tz/africa

@@ -30,6 +30,10 @@
 # Milne J. Civil time. Geogr J. 1899 Feb;13(2):173-94.
 # https://www.jstor.org/stable/1774359
 #
+# For the 1911/1912 establishment of standard time in French possessions, see:
+# Société Française de Physique, Recueil de constantes physiques (1913),
+# page 752, 18b.
+#
 # European-style abbreviations are commonly used along the Mediterranean.
 # For sub-Saharan Africa abbreviations were less standardized.
 # Previous editions of this database used WAT, CAT, SAT, and EAT
@@ -113,7 +117,7 @@ Zone Atlantic/Cape_Verde -1:34:04 -	LMT	1912 Jan 01  2:00u # Praia
 
 # Chad
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
-Zone	Africa/Ndjamena	1:00:12 -	LMT	1912        # N'Djamena
+Zone	Africa/Ndjamena	1:00:12 -	LMT	1912 Jan  1 # N'Djamena
 			1:00	-	WAT	1979 Oct 14
 			1:00	1:00	WAST	1980 Mar  8
 			1:00	-	WAT
@@ -139,7 +143,7 @@ Zone	Africa/Ndjamena	1:00:12 -	LMT	1912        # N'Djamena
 #	Inaccessible, Nightingale: uninhabited
 
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
-Zone	Africa/Abidjan	-0:16:08 -	LMT	1912
+Zone	Africa/Abidjan	-0:16:08 -	LMT	1912 Jan  1
 			 0:00	-	GMT
 
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