contrib/tzdata: import tzdata 2023d

Changes: https://github.com/eggert/tz/blob/2023d/NEWS

MFC after:	1 day

20 files changed, 763 insertions, 168 deletions

diff --git a/contrib/tzdata/Makefile b/contrib/tzdata/Makefile
index 6edc73cc6ffb..4e45f93b915c 100644
--- a/contrib/tzdata/Makefile
+++ b/contrib/tzdata/Makefile
@@ -1,7 +1,25 @@
 # 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.
+# Request POSIX conformance; this must be the first non-comment line.
+.POSIX:
+# On older platforms you may need to scrounge for a POSIX-conforming 'make'.
+# For example, on Solaris 10 (2005), use /usr/sfw/bin/gmake or
+# /usr/xpg4/bin/make, not /usr/ccs/bin/make.
+
+# To affect how this Makefile works, you can run a shell script like this:
+#
+#	#!/bin/sh
+#	make CC='gcc -std=gnu11' "$@"
+#
+# This example script is appropriate for a pre-2017 GNU/Linux system
+# where a non-default setting is needed to support this package's use of C99.
+#
+# Alternatively, you can simply edit this Makefile to tailor the following
+# macro definitions.
+
+###############################################################################
+# Start of macros that one plausibly might want to tailor.
 
 # Package name for the code distribution.
 PACKAGE=	tzcode
@@ -191,8 +209,9 @@ UTF8_LOCALE=	en_US.utf8
 # 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".
+# Add the following to an uncommented "CFLAGS=" line as needed
+# to override defaults specified in the source code or by the system.
+# "-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
@@ -234,11 +253,16 @@ LDLIBS=
 #  -DHAVE_UNISTD_H=0 if <unistd.h> does not work*
 #  -DHAVE_UTMPX_H=0 if <utmpx.h> 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+
+#  -DPORT_TO_C89 if tzcode should also run on mostly-C89 platforms+
+#	Typically it is better to use a later standard.  For example,
+#	with GCC 4.9.4 (2016), prefer '-std=gnu11' to '-DPORT_TO_C89'.
+#	Even with -DPORT_TO_C89, the code needs at least one C99
+#	feature (integers at least 64 bits wide) and maybe more.
 #  -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+
+#	However, this might trigger latent bugs in C99-or-later 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;
@@ -270,11 +294,15 @@ LDLIBS=
 #  -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)
+#  -g to generate symbolic debugging info
+#  -Idir to include from directory 'dir'
+#  -O0 to disable optimization; other -O options to enable more optimization
+#  -Uname to remove any definition of the macro 'name'
 #  $(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.
+#   once the code assumes C99 or later, say in the year 2029.
 #
 # Select instrumentation via "make GCC_INSTRUMENT='whatever'".
 GCC_INSTRUMENT = \
@@ -353,9 +381,11 @@ GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \
 # 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.
-# "timelocal" is equivalent to "mktime".
+# I.e., "offtime" is like calling "localtime_rz" with a fixed-offset zone.
+# "timelocal" is nearly 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.
+# I.e., "timeoff" is like calling "mktime_z" with a fixed-offset zone.
 # "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
@@ -378,7 +408,7 @@ GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \
 #
 # 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
+# which claims to test C and POSIX conformance.  If you want to pass PCTS, add
 #	-DPCTS
 # to the end of the "CFLAGS=" line.
 #
@@ -388,13 +418,21 @@ GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \
 # 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.
+#
+# POSIX says CFLAGS defaults to "-O 1".
+# Uncomment the following line and edit its contents as needed.
 
-CFLAGS=
+#CFLAGS= -O 1
 
-# Linker flags.  Default to $(LFLAGS) for backwards compatibility
-# to release 2012h and earlier.
 
-LDFLAGS=	$(LFLAGS)
+# 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.
+#AR = ar
+#ARFLAGS = -rv
+#CC = c17
+#LDFLAGS =
+#MAKE = make
 
 # For leap seconds, this Makefile uses LEAPSECONDS='-L leapseconds' in
 # submake command lines.  The default is no leap seconds.
@@ -418,18 +456,18 @@ ZFLAGS=
 
 ZIC_INSTALL=	$(ZIC) -d '$(DESTDIR)$(TZDIR)' $(LEAPSECONDS)
 
-# The name of a Posix-compliant 'awk' on your system.
+# 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 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
+# lacks 'select' or doesn't completely conform to POSIX, but /bin/bash
 # is typically nicer if it works.
 KSHELL=		/bin/bash
 
@@ -503,17 +541,16 @@ GZIPFLAGS=	-9n
 DIFF_TZS=	 diff -u$$(! diff -u -F'^TZ=' - - <>/dev/null >&0 2>&1 \
 			   || echo ' -F^TZ=')
 
-###############################################################################
-
-#MAKE=		make
+# ':' on typical hosts; 'ranlib' on the ancient hosts that still need ranlib.
+RANLIB=		:
 
-cc=		cc
-CC=		$(cc) -DTZDIR='"$(TZDIR)"'
+# POSIX prohibits defining or using SHELL.  However, csh users on systems
+# that use the user shell for Makefile commands may need to define SHELL.
+#SHELL=		/bin/sh
 
-AR=		ar
+# End of macros that one plausibly might want to tailor.
+###############################################################################
 
-# ':' 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
@@ -543,7 +580,7 @@ YDATA=		$(PRIMARY_YDATA) etcetera
 NDATA=		factory
 TDATA_TO_CHECK=	$(YDATA) $(NDATA) backward
 TDATA=		$(YDATA) $(NDATA) $(BACKWARD)
-ZONETABLES=	zone1970.tab zone.tab
+ZONETABLES=	zone.tab zone1970.tab zonenow.tab
 TABDATA=	iso3166.tab $(TZDATA_TEXT) $(ZONETABLES)
 LEAP_DEPS=	leapseconds.awk leap-seconds.list
 TZDATA_ZI_DEPS=	ziguard.awk zishrink.awk version $(TDATA) \
@@ -551,7 +588,7 @@ TZDATA_ZI_DEPS=	ziguard.awk zishrink.awk version $(TDATA) \
 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 \
+AWK_SCRIPTS=	checklinks.awk checknow.awk checktab.awk leapseconds.awk \
 			ziguard.awk zishrink.awk
 MISC=		$(AWK_SCRIPTS)
 TZS_YEAR=	2050
@@ -572,7 +609,7 @@ VERSION_DEPS= \
 		calendars CONTRIBUTING LICENSE Makefile NEWS README SECURITY \
 		africa antarctica asctime.c asia australasia \
 		backward backzone \
-		checklinks.awk checktab.awk \
+		checklinks.awk checknow.awk checktab.awk \
 		date.1 date.c difftime.c \
 		etcetera europe factory iso3166.tab \
 		leap-seconds.list leapseconds.awk localtime.c \
@@ -582,12 +619,7 @@ VERSION_DEPS= \
 		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
+		zone.tab zone1970.tab zonenow.tab
 
 all:		tzselect zic zdump libtz.a $(TABDATA) \
 		  vanguard.zi main.zi rearguard.zi
@@ -657,6 +689,16 @@ tzdata.zi:	$(DATAFORM).zi version zishrink.awk
 		    $(DATAFORM).zi >$@.out
 		mv $@.out $@
 
+tzdir.h:
+		printf '%s\n' >$@.out \
+		  '#ifndef TZDEFAULT' \
+		  '# define TZDEFAULT "$(TZDEFAULT)" /* default zone */' \
+		  '#endif' \
+		  '#ifndef TZDIR' \
+		  '# define TZDIR "$(TZDIR)" /* TZif directory */' \
+		  '#endif'
+		mv $@.out $@
+
 version.h:	version
 		VERSION=`cat version` && printf '%s\n' \
 		  'static char const PKGVERSION[]="($(PACKAGE)) ";' \
@@ -763,7 +805,7 @@ force_tzs:	$(TZS_NEW)
 
 libtz.a:	$(LIBOBJS)
 		rm -f $@
-		$(AR) -rc $@ $(LIBOBJS)
+		$(AR) $(ARFLAGS) $@ $(LIBOBJS)
 		$(RANLIB) $@
 
 date:		$(DATEOBJS)
@@ -771,26 +813,32 @@ date:		$(DATEOBJS)
 
 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
+		  -e "s'#!/bin/bash'#!"'$(KSHELL)'\' \
+		  -e s\''\(AWK\)=[^}]*'\''\1=\'\''$(AWK)\'\'\' \
+		  -e s\''\(PKGVERSION\)=.*'\''\1=\'\''($(PACKAGE)) \'\'\' \
+		  -e s\''\(REPORT_BUGS_TO\)=.*'\''\1=\'\''$(BUGEMAIL)\'\'\' \
+		  -e s\''\(TZDIR\)=[^}]*'\''\1=\'\''$(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_name_lengths check_now \
+		  check_slashed_abbrs check_sorted \
 		  check_tables check_web check_ziguard check_zishrink check_tzs
 
+# True if UTF8_LOCALE does not work;
+# otherwise, false but with LC_ALL set to $(UTF8_LOCALE).
+UTF8_LOCALE_MISSING = \
+  { test ! '$(UTF8_LOCALE)' \
+    || ! printf 'A\304\200B\n' \
+         | LC_ALL='$(UTF8_LOCALE)' grep -q '^A.B$$' >/dev/null 2>&1 \
+    || { LC_ALL='$(UTF8_LOCALE)'; export LC_ALL; false; }; }
+
 check_character_set: $(ENCHILADA)
-	test ! '$(UTF8_LOCALE)' || \
-	! printf 'A\304\200B\n' | \
-	  LC_ALL='$(UTF8_LOCALE)' grep -q '^A.B$$' >/dev/null 2>&1 || { \
-		LC_ALL='$(UTF8_LOCALE)' && export LC_ALL && \
+	$(UTF8_LOCALE_MISSING) || { \
 		sharp='#' && \
 		! grep -Env $(SAFE_LINE) $(MANS) date.1 $(MANTXTS) \
 			$(MISC) $(SOURCES) $(WEB_PAGES) \
@@ -805,12 +853,12 @@ check_character_set: $(ENCHILADA)
 	touch $@
 
 check_white_space: $(ENCHILADA)
+	$(UTF8_LOCALE_MISSING) || { \
 		patfmt=' \t|[\f\r\v]' && pat=`printf "$$patfmt\\n"` && \
-		! grep -En "$$pat" \
-			$$(ls $(ENCHILADA) | grep -Fvx leap-seconds.list)
-		! grep -n '[$s]$$' \
-			$$(ls $(ENCHILADA) | grep -Fvx leap-seconds.list)
-		touch $@
+		! grep -En "$$pat|[$s]\$$" \
+			$$(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}
@@ -851,7 +899,29 @@ check_links:	checklinks.awk tzdata.zi
 		  -f checklinks.awk tzdata.zi
 		touch $@
 
-check_tables:	checktab.awk $(YDATA) backward $(ZONETABLES)
+# Check timestamps from now through 28 years from now, to make sure
+# that zonenow.tab contains all sequences of planned timestamps,
+# without any duplicate sequences.  In theory this might require
+# 2800 years but that would take a long time to check.
+CHECK_NOW_TIMESTAMP = `./date +%s`
+CHECK_NOW_FUTURE_YEARS = 28
+CHECK_NOW_FUTURE_SECS = $(CHECK_NOW_FUTURE_YEARS) '*' 366 '*' 24 '*' 60 '*' 60
+check_now:	checknow.awk date tzdata.zi zdump zic zone1970.tab zonenow.tab
+		rm -fr $@.dir
+		mkdir $@.dir
+		./zic -d $@.dir tzdata.zi
+		now=$(CHECK_NOW_TIMESTAMP) && \
+		  future=`expr $(CHECK_NOW_FUTURE_SECS) + $$now` && \
+		  ./zdump -i -t $$now,$$future \
+		     $$(find $$PWD/$@.dir/????*/ -type f) \
+		     >$@.dir/zdump.tab
+		$(AWK) \
+		  -v zdump_table=$@.dir/zdump.tab \
+		  -f checknow.awk zonenow.tab
+		rm -fr $@.dir
+		touch $@
+
+check_tables:	checktab.awk $(YDATA) backward zone.tab zone1970.tab
 		for tab in $(ZONETABLES); do \
 		  test "$$tab" = zone.tab && links='$(BACKWARD)' || links=''; \
 		  $(AWK) -f checktab.awk -v zone_table=$$tab $(YDATA) $$links \
@@ -911,10 +981,10 @@ check_zishrink_posix check_zishrink_right: \
 		touch $@
 
 clean_misc:
-		rm -fr check_*.dir
+		rm -fr check_*.dir typecheck_*.dir
 		rm -f *.o *.out $(TIME_T_ALTERNATIVES) \
 		  check_* core typecheck_* \
-		  date tzselect version.h zdump zic libtz.a
+		  date tzdir.h tzselect version.h zdump zic libtz.a
 clean:		clean_misc
 		rm -fr *.dir tzdb-*/
 		rm -f *.zi $(TZS_NEW)
@@ -952,12 +1022,18 @@ $(MANTXTS):	workman.sh
 # 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" && \
+  <"$$dest" && \
   if test $$n != 0 && \
-     lsout=`ls -n --time-style="+%s" "$$dest" 2>/dev/null`; then \
+     lsout=`ls -nt --time-style="+%s" "$$@" 2>/dev/null`; then \
     set x $$lsout && \
-    touch -cmd @`expr $$7 + $$n` "$$dest"; \
-  else :; fi'
+    timestamp=`expr $$7 + $$n` && \
+    echo "+ touch -md @$$timestamp $$dest" && \
+    touch -md @$$timestamp "$$dest"; \
+  else \
+    newest=`ls -t "$$@" | sed 1q` && \
+    echo "+ touch -mr $$newest $$dest" && \
+    touch -mr "$$newest" "$$dest"; \
+  fi'
 # If DEST depends on A B C ... in this Makefile, callers should use
 # $(SET_TIMESTAMP_DEP) DEST A B C ..., for the benefit of any
 # downstream 'make' that considers equal timestamps to be out of date.
@@ -982,8 +1058,12 @@ set-timestamps.out: $(EIGHT_YARDS)
 		  rm -f test.out && \
 		  for file in $$files; do \
 		    if git diff --quiet $$file; then \
-		      time=`git log -1 --format='tformat:%ct' $$file` && \
-		      touch -cmd @$$time $$file; \
+		      time=`TZ=UTC0 git log -1 \
+			--format='tformat:%cd' \
+			--date='format:%Y-%m-%dT%H:%M:%SZ' \
+			$$file` && \
+		      echo "+ touch -md $$time $$file" && \
+		      touch -md $$time $$file; \
 		    else \
 		      echo >&2 "$$file: warning: does not match repository"; \
 		    fi || exit; \
@@ -1008,7 +1088,8 @@ 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
+		cd public.dir \
+		  && $(MAKE) CFLAGS='$(GCC_DEBUG_FLAGS)' TZDIR='$(TZDIR)' ALL
 		for i in $(TDATA_TO_CHECK) public.dir/tzdata.zi \
 		    public.dir/vanguard.zi public.dir/main.zi \
 		    public.dir/rearguard.zi; \
@@ -1139,7 +1220,7 @@ tzdata$(VERSION)-rearguard.tar.gz: rearguard.zi set-timestamps.out
 		sed '1s/$$/-rearguard/' <version >$@.dir/version
 		: The dummy pacificnew pacifies TZUpdater 2.3.1 and earlier.
 		$(CREATE_EMPTY) $@.dir/pacificnew
-		touch -cmr version $@.dir/version
+		touch -mr version $@.dir/version
 		LC_ALL=C && export LC_ALL && \
 		  (cd $@.dir && \
 		   tar $(TARFLAGS) -cf - \
@@ -1163,7 +1244,7 @@ tzdata$(VERSION)-tailored.tar.gz: set-timestamps.out
 		  `test $(DATAFORM) = vanguard || echo pacificnew`
 		(grep '^#' tzdata.zi && echo && cat $(DATAFORM).zi) \
 		  >$@.dir/etcetera
-		touch -cmr tzdata.zi $@.dir/etcetera
+		touch -mr tzdata.zi $@.dir/etcetera
 		sed -n \
 		  -e '/^# *version  *\(.*\)/h' \
 		  -e '/^# *ddeps  */H' \
@@ -1174,7 +1255,7 @@ tzdata$(VERSION)-tailored.tar.gz: set-timestamps.out
 		  -e 's/ /-/g' \
 		  -e 'p' \
 		  <tzdata.zi >$@.dir/version
-		touch -cmr version $@.dir/version
+		touch -mr version $@.dir/version
 		links= && \
 		  for file in $(TZDATA_DIST); do \
 		    test -f $@.dir/$$file || links="$$links $$file"; \
@@ -1226,10 +1307,10 @@ zonenames:	tzdata.zi
 asctime.o:	private.h tzfile.h
 date.o:		private.h
 difftime.o:	private.h
-localtime.o:	private.h tzfile.h
+localtime.o:	private.h tzfile.h tzdir.h
 strftime.o:	private.h tzfile.h
 zdump.o:	version.h
-zic.o:		private.h tzfile.h version.h
+zic.o:		private.h tzfile.h tzdir.h version.h
 
 .PHONY: ALL INSTALL all
 .PHONY: check check_mild check_time_t_alternatives
diff --git a/contrib/tzdata/NEWS b/contrib/tzdata/NEWS
index b54538aa4a82..031ba6a8a250 100644
--- a/contrib/tzdata/NEWS
+++ b/contrib/tzdata/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.
 
diff --git a/contrib/tzdata/README b/contrib/tzdata/README
index 145aacd495b7..edabd2e0690f 100644
--- a/contrib/tzdata/README
+++ b/contrib/tzdata/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.
 
diff --git a/contrib/tzdata/africa b/contrib/tzdata/africa
index 6cf4e39c8c45..6fae18c0979f 100644
--- a/contrib/tzdata/africa
+++ b/contrib/tzdata/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
diff --git a/contrib/tzdata/antarctica b/contrib/tzdata/antarctica
index fc603e9996de..763c27253c99 100644
--- a/contrib/tzdata/antarctica
+++ b/contrib/tzdata/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
diff --git a/contrib/tzdata/asia b/contrib/tzdata/asia
index a29a4dc0c4de..04526c196931 100644
--- a/contrib/tzdata/asia
+++ b/contrib/tzdata/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	-
diff --git a/contrib/tzdata/australasia b/contrib/tzdata/australasia
index 0633a30efd8b..dc98c1e2de17 100644
--- a/contrib/tzdata/australasia
+++ b/contrib/tzdata/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
diff --git a/contrib/tzdata/backward b/contrib/tzdata/backward
index 421f2ec6b9f8..65c711b37bf4 100644
--- a/contrib/tzdata/backward
+++ b/contrib/tzdata/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
diff --git a/contrib/tzdata/backzone b/contrib/tzdata/backzone
index 44d81c29e5ae..f45250340493 100644
--- a/contrib/tzdata/backzone
+++ b/contrib/tzdata/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.
diff --git a/contrib/tzdata/checknow.awk b/contrib/tzdata/checknow.awk
new file mode 100644
index 000000000000..d722c03fd689
--- /dev/null
+++ b/contrib/tzdata/checknow.awk
@@ -0,0 +1,54 @@
+# Check zonenow.tab for consistency with primary data.
+
+# Contributed by Paul Eggert.  This file is in the public domain.
+
+function record_zone(zone, data) {
+  if (zone) {
+    zone_data[zone] = data
+    zones[data] = zones[data] " " zone
+  }
+}
+
+BEGIN {
+  while (getline <zdump_table) {
+    if ($0 ~ /^TZ/) {
+      record_zone(zone, data)
+      zone = $0
+      sub(/.*\.dir\//, "", zone)
+      sub(/\/\//, "/", zone)
+      sub(/"/, "", zone)
+      data = ""
+    } else if ($0 ~ /./)
+      data = data $0 "\n"
+  }
+  record_zone(zone, data)
+  FS = "\t"
+}
+
+/^[^#]/ {
+  zone = $3
+  data = zone_data[zone]
+  if (!data) {
+    printf "%s: no data\n", zone
+    status = 1
+  } else {
+    zone2 = zonenow[data]
+    if (zone2) {
+      printf "zones %s and %s identical from now on\n", zone, zone2
+      status = 1
+    } else
+      zonenow[data] = zone
+  }
+}
+
+END {
+ for (zone in zone_data) {
+    data = zone_data[zone]
+    if (!zonenow[data]) {
+      printf "checknow.tab should have one of:%s\n", zones[data]
+      zonenow[data] = zone # This suppresses duplicate diagnostics.
+      status = 1
+    }
+ }
+ exit status
+}
diff --git a/contrib/tzdata/checktab.awk b/contrib/tzdata/checktab.awk
index 2dbf485fda3a..9a26e4655ddb 100644
--- a/contrib/tzdata/checktab.awk
+++ b/contrib/tzdata/checktab.awk
@@ -83,7 +83,7 @@ BEGIN {
 		    cc = cca[i]
 		    if (cc2name[cc]) {
 			cc_used[cc]++
-		    } else {
+		    } else if (! (cc == "XX" && zone_table == "zonenow.tab")) {
 			printf "%s:%d: %s: unknown country code\n", \
 				zone_table, zone_NR, cc >>"/dev/stderr"
 			status = 1
@@ -110,7 +110,7 @@ BEGIN {
 	      used_max_cc = cc
 	    }
 	  }
-	  if (used_max <= 1 && comments) {
+	  if (used_max <= 1 && comments && zone_table != "zonenow.tab") {
 	    printf "%s:%d: unnecessary comment '%s'\n", \
 	      zone_table, i, comments \
 	      >>"/dev/stderr"
@@ -149,7 +149,8 @@ $1 ~ /^#/ { next }
 		if ($3 ~ /%/) rulePercentUsed[$2] = 1
 	}
 	if (tz && tz ~ /\// && tz !~ /^Etc\//) {
-		if (!tztab[tz] && FILENAME != "backward") {
+		if (!tztab[tz] && FILENAME != "backward" \
+		    && zone_table != "zonenow.tab") {
 			printf "%s: no data for '%s'\n", zone_table, tz \
 				>>"/dev/stderr"
 			status = 1
diff --git a/contrib/tzdata/europe b/contrib/tzdata/europe
index 3907c055140a..27f821e77600 100644
--- a/contrib/tzdata/europe
+++ b/contrib/tzdata/europe
@@ -1123,6 +1123,23 @@ Zone Atlantic/Faroe	-0:27:04 -	LMT	1908 Jan 11 # Tórshavn
 # 2. The shift *from* DST in 2023 happens as normal, but coincides with the
 #    shift to UTC-02 normaltime (people will not change their clocks here).
 # 3. After this, DST is still observed, but as -02/-01 instead of -03/-02.
+#
+# From Múte Bourup Egede via Jógvan Svabo Samuelsen (2023-03-15):
+# Greenland will not switch to Daylight Saving Time this year, 2023,
+# because the standard time for Greenland will change from UTC -3 to UTC -2.
+# However, Greenland will change to Daylight Saving Time again in 2024
+# and onwards.
+
+# From a contributor who wishes to remain anonymous for now (2023-10-29):
+# https://www.dr.dk/nyheder/seneste/i-nat-skal-uret-stilles-en-time-tilbage-men-foerste-gang-sker-det-ikke-i-groenland
+# with a link to that page:
+# https://naalakkersuisut.gl/Nyheder/2023/10/2710_sommertid
+# ... Ittoqqortoormiit joins the time of Nuuk at March 2024.
+# What would mean that America/Scoresbysund would either be in -01 year round
+# or in -02/-01 like America/Nuuk, but no longer in -01/+00.
+#
+# From Paul Eggert (2023-10-29):
+# For now, assume it will be like America/Nuuk.
 
 # Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Thule	1991	1992	-	Mar	lastSun	2:00	1:00	D
@@ -1143,10 +1160,12 @@ Zone America/Danmarkshavn -1:14:40 -	LMT	1916 Jul 28
 Zone America/Scoresbysund -1:27:52 -	LMT	1916 Jul 28 # Ittoqqortoormiit
 			-2:00	-	-02	1980 Apr  6  2:00
 			-2:00	C-Eur	-02/-01	1981 Mar 29
-			-1:00	EU	-01/+00
+			-1:00	EU	-01/+00 2024 Mar 31
+			-2:00	EU	-02/-01
 Zone America/Nuuk	-3:26:56 -	LMT	1916 Jul 28 # Godthåb
 			-3:00	-	-03	1980 Apr  6  2:00
-			-3:00	EU	-03/-02	2023 Oct 29  1:00u
+			-3:00	EU	-03/-02	2023 Mar 26  1:00u
+			-2:00	-	-02	2023 Oct 29  1:00u
 			-2:00	EU	-02/-01
 Zone America/Thule	-4:35:08 -	LMT	1916 Jul 28 # Pituffik
 			-4:00	Thule	A%sT
@@ -3711,11 +3730,7 @@ Zone	Europe/Istanbul	1:55:52 -	LMT	1880
 # and not at 3:00 as would have been under EU rules.
 # This is why I have set the change to EU rules into May 1996,
 # so that the change in March is stil covered by the Ukraine rule.
-# The next change in October 1996 happened under EU rules....
-# TZ database holds three other zones for Ukraine.... I have not yet
-# worked out the consequences for these three zones, as we (me and my
-# US colleague David Cochrane) are still trying to get more
-# information upon these local deviations from Kiev rules.
+# The next change in October 1996 happened under EU rules.
 #
 # From Paul Eggert (2022-08-27):
 # For now, assume that Ukraine's zones all followed the same rules,
diff --git a/contrib/tzdata/leap-seconds.list b/contrib/tzdata/leap-seconds.list
index 17e3a100f943..3fe9a1210e3c 100644
--- a/contrib/tzdata/leap-seconds.list
+++ b/contrib/tzdata/leap-seconds.list
@@ -204,10 +204,10 @@
 #	current -- the update time stamp, the data and the name of the file
 #	will not change.
 #
-#	Updated through IERS Bulletin C65
-#	File expires on:  28 December 2023
+#	Updated through IERS Bulletin C66
+#	File expires on:  28 June 2024
 #
-#@	3912710400
+#@	3928521600
 #
 2272060800	10	# 1 Jan 1972
 2287785600	11	# 1 Jul 1972
@@ -252,4 +252,4 @@
 #	the hash line is also ignored in the
 #	computation.
 #
-#h 	e76a99dc 65f15cc7 e613e040 f5078b5e b23834fe
+#h 	16edd0f0 3666784f 37db6bdd e74ced87 59af48f1
diff --git a/contrib/tzdata/leapseconds b/contrib/tzdata/leapseconds
index a6a170aa7028..8938c763e0ed 100644
--- a/contrib/tzdata/leapseconds
+++ b/contrib/tzdata/leapseconds
@@ -72,11 +72,11 @@ Leap	2016	Dec	31	23:59:60	+	S
 # Any additional leap seconds will come after this.
 # This Expires line is commented out for now,
 # so that pre-2020a zic implementations do not reject this file.
-#Expires 2023	Dec	28	00:00:00
+#Expires 2024	Jun	28	00:00:00
 
 # POSIX timestamps for the data in this file:
 #updated 1467936000 (2016-07-08 00:00:00 UTC)
-#expires 1703721600 (2023-12-28 00:00:00 UTC)
+#expires 1719532800 (2024-06-28 00:00:00 UTC)
 
-#	Updated through IERS Bulletin C65
-#	File expires on:  28 December 2023
+#	Updated through IERS Bulletin C66
+#	File expires on:  28 June 2024
diff --git a/contrib/tzdata/northamerica b/contrib/tzdata/northamerica
index d8e3601ca219..8ac106ab2229 100644
--- a/contrib/tzdata/northamerica
+++ b/contrib/tzdata/northamerica
@@ -1453,7 +1453,7 @@ Rule	StJohns	1989	2006	-	Apr	Sun>=1	0:01	1:00	D
 Rule	StJohns	2007	2011	-	Mar	Sun>=8	0:01	1:00	D
 Rule	StJohns	2007	2010	-	Nov	Sun>=1	0:01	0	S
 #
-# St John's has an apostrophe, but Posix file names can't have apostrophes.
+# St John's has an apostrophe, but POSIX file names can't have apostrophes.
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
 Zone America/St_Johns	-3:30:52 -	LMT	1884
 			-3:30:52 StJohns N%sT	1918
diff --git a/contrib/tzdata/southamerica b/contrib/tzdata/southamerica
index e55c5f0842c0..19c7e4566cd4 100644
--- a/contrib/tzdata/southamerica
+++ b/contrib/tzdata/southamerica
@@ -1697,6 +1697,12 @@ Rule	Para	2010	2012	-	Apr	Sun>=8	0:00	0	-
 # From Carlos Raúl Perasso (2014-02-28):
 # Decree 1264 can be found at:
 # http://www.presidencia.gov.py/archivos/documentos/DECRETO1264_ey9r8zai.pdf
+#
+# From Paul Eggert (2023-07-26):
+# Transition dates are now set by Law No. 7115, not by presidential decree.
+# https://www.abc.com.py/politica/2023/07/12/promulgacion-el-cambio-de-hora-sera-por-ley/
+# From Carlos Raúl Perasso (2023-07-27):
+# http://silpy.congreso.gov.py/descarga/ley-144138
 Rule	Para	2013	max	-	Mar	Sun>=22	0:00	0	-
 
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
diff --git a/contrib/tzdata/version b/contrib/tzdata/version
index 7daa77e00d99..cd9c3f6d6e52 100644
--- a/contrib/tzdata/version
+++ b/contrib/tzdata/version
@@ -1 +1 @@
-2023c
+2023d
diff --git a/contrib/tzdata/zone.tab b/contrib/tzdata/zone.tab
index dbcb61793eeb..3fa9306afbad 100644
--- a/contrib/tzdata/zone.tab
+++ b/contrib/tzdata/zone.tab
@@ -48,7 +48,7 @@ AR	-3124-06411	America/Argentina/Cordoba	Argentina (most areas: CB, CC, CN, ER,
 AR	-2447-06525	America/Argentina/Salta	Salta (SA, LP, NQ, RN)
 AR	-2411-06518	America/Argentina/Jujuy	Jujuy (JY)
 AR	-2649-06513	America/Argentina/Tucuman	Tucuman (TM)
-AR	-2828-06547	America/Argentina/Catamarca	Catamarca (CT); Chubut (CH)
+AR	-2828-06547	America/Argentina/Catamarca	Catamarca (CT), Chubut (CH)
 AR	-2926-06651	America/Argentina/La_Rioja	La Rioja (LR)
 AR	-3132-06831	America/Argentina/San_Juan	San Juan (SJ)
 AR	-3253-06849	America/Argentina/Mendoza	Mendoza (MZ)
@@ -87,7 +87,7 @@ BN	+0456+11455	Asia/Brunei
 BO	-1630-06809	America/La_Paz
 BQ	+120903-0681636	America/Kralendijk
 BR	-0351-03225	America/Noronha	Atlantic islands
-BR	-0127-04829	America/Belem	Para (east); Amapa
+BR	-0127-04829	America/Belem	Para (east), Amapa
 BR	-0343-03830	America/Fortaleza	Brazil (northeast: MA, PI, CE, RN, PB)
 BR	-0803-03454	America/Recife	Pernambuco
 BR	-0712-04812	America/Araguaina	Tocantins
@@ -107,21 +107,21 @@ BT	+2728+08939	Asia/Thimphu
 BW	-2439+02555	Africa/Gaborone
 BY	+5354+02734	Europe/Minsk
 BZ	+1730-08812	America/Belize
-CA	+4734-05243	America/St_Johns	Newfoundland; Labrador (southeast)
-CA	+4439-06336	America/Halifax	Atlantic - NS (most areas); PE
+CA	+4734-05243	America/St_Johns	Newfoundland, Labrador (SE)
+CA	+4439-06336	America/Halifax	Atlantic - NS (most areas), PE
 CA	+4612-05957	America/Glace_Bay	Atlantic - NS (Cape Breton)
 CA	+4606-06447	America/Moncton	Atlantic - New Brunswick
 CA	+5320-06025	America/Goose_Bay	Atlantic - Labrador (most areas)
 CA	+5125-05707	America/Blanc-Sablon	AST - QC (Lower North Shore)
-CA	+4339-07923	America/Toronto	Eastern - ON, QC (most areas)
+CA	+4339-07923	America/Toronto	Eastern - ON & QC (most areas)
 CA	+6344-06828	America/Iqaluit	Eastern - NU (most areas)
-CA	+484531-0913718	America/Atikokan	EST - ON (Atikokan); NU (Coral H)
-CA	+4953-09709	America/Winnipeg	Central - ON (west); Manitoba
+CA	+484531-0913718	America/Atikokan	EST - ON (Atikokan), NU (Coral H)
+CA	+4953-09709	America/Winnipeg	Central - ON (west), Manitoba
 CA	+744144-0944945	America/Resolute	Central - NU (Resolute)
 CA	+624900-0920459	America/Rankin_Inlet	Central - NU (central)
 CA	+5024-10439	America/Regina	CST - SK (most areas)
 CA	+5017-10750	America/Swift_Current	CST - SK (midwest)
-CA	+5333-11328	America/Edmonton	Mountain - AB; BC (E); NT (E); SK (W)
+CA	+5333-11328	America/Edmonton	Mountain - AB, BC(E), NT(E), SK(W)
 CA	+690650-1050310	America/Cambridge_Bay	Mountain - NU (west)
 CA	+682059-1334300	America/Inuvik	Mountain - NT (west)
 CA	+4906-11631	America/Creston	MST - BC (Creston)
@@ -207,8 +207,8 @@ HT	+1832-07220	America/Port-au-Prince
 HU	+4730+01905	Europe/Budapest
 ID	-0610+10648	Asia/Jakarta	Java, Sumatra
 ID	-0002+10920	Asia/Pontianak	Borneo (west, central)
-ID	-0507+11924	Asia/Makassar	Borneo (east, south); Sulawesi/Celebes, Bali, Nusa Tengarra; Timor (west)
-ID	-0232+14042	Asia/Jayapura	New Guinea (West Papua / Irian Jaya); Malukus/Moluccas
+ID	-0507+11924	Asia/Makassar	Borneo (east, south), Sulawesi/Celebes, Bali, Nusa Tengarra, Timor (west)
+ID	-0232+14042	Asia/Jayapura	New Guinea (West Papua / Irian Jaya), Malukus/Moluccas
 IE	+5320-00615	Europe/Dublin
 IL	+314650+0351326	Asia/Jerusalem
 IM	+5409-00428	Europe/Isle_of_Man
@@ -355,7 +355,7 @@ RU	+4310+13156	Asia/Vladivostok	MSK+07 - Amur River
 RU	+643337+1431336	Asia/Ust-Nera	MSK+07 - Oymyakonsky
 RU	+5934+15048	Asia/Magadan	MSK+08 - Magadan
 RU	+4658+14242	Asia/Sakhalin	MSK+08 - Sakhalin Island
-RU	+6728+15343	Asia/Srednekolymsk	MSK+08 - Sakha (E); N Kuril Is
+RU	+6728+15343	Asia/Srednekolymsk	MSK+08 - Sakha (E), N Kuril Is
 RU	+5301+15839	Asia/Kamchatka	MSK+09 - Kamchatka
 RU	+6445+17729	Asia/Anadyr	MSK+09 - Bering Sea
 RW	-0157+03004	Africa/Kigali
@@ -418,7 +418,7 @@ US	+470659-1011757	America/North_Dakota/Center	Central - ND (Oliver)
 US	+465042-1012439	America/North_Dakota/New_Salem	Central - ND (Morton rural)
 US	+471551-1014640	America/North_Dakota/Beulah	Central - ND (Mercer)
 US	+394421-1045903	America/Denver	Mountain (most areas)
-US	+433649-1161209	America/Boise	Mountain - ID (south); OR (east)
+US	+433649-1161209	America/Boise	Mountain - ID (south), OR (east)
 US	+332654-1120424	America/Phoenix	MST - AZ (except Navajo)
 US	+340308-1181434	America/Los_Angeles	Pacific
 US	+611305-1495401	America/Anchorage	Alaska (most areas)
diff --git a/contrib/tzdata/zone1970.tab b/contrib/tzdata/zone1970.tab
index 0cd2e06ee998..a01f26d94a2d 100644
--- a/contrib/tzdata/zone1970.tab
+++ b/contrib/tzdata/zone1970.tab
@@ -38,7 +38,7 @@
 #country-
 #codes	coordinates	TZ	comments
 AD	+4230+00131	Europe/Andorra
-AE,OM,RE,SC,TF	+2518+05518	Asia/Dubai	Crozet, Scattered Is
+AE,OM,RE,SC,TF	+2518+05518	Asia/Dubai	Crozet
 AF	+3431+06912	Asia/Kabul
 AL	+4120+01950	Europe/Tirane
 AM	+4011+04430	Asia/Yerevan
@@ -48,12 +48,13 @@ AQ	-6736+06253	Antarctica/Mawson	Mawson
 AQ	-6448-06406	Antarctica/Palmer	Palmer
 AQ	-6734-06808	Antarctica/Rothera	Rothera
 AQ	-720041+0023206	Antarctica/Troll	Troll
+AQ	-7824+10654	Antarctica/Vostok	Vostok
 AR	-3436-05827	America/Argentina/Buenos_Aires	Buenos Aires (BA, CF)
 AR	-3124-06411	America/Argentina/Cordoba	most areas: CB, CC, CN, ER, FM, MN, SE, SF
 AR	-2447-06525	America/Argentina/Salta	Salta (SA, LP, NQ, RN)
 AR	-2411-06518	America/Argentina/Jujuy	Jujuy (JY)
 AR	-2649-06513	America/Argentina/Tucuman	Tucumán (TM)
-AR	-2828-06547	America/Argentina/Catamarca	Catamarca (CT); Chubut (CH)
+AR	-2828-06547	America/Argentina/Catamarca	Catamarca (CT), Chubut (CH)
 AR	-2926-06651	America/Argentina/La_Rioja	La Rioja (LR)
 AR	-3132-06831	America/Argentina/San_Juan	San Juan (SJ)
 AR	-3253-06849	America/Argentina/Mendoza	Mendoza (MZ)
@@ -82,7 +83,7 @@ BG	+4241+02319	Europe/Sofia
 BM	+3217-06446	Atlantic/Bermuda
 BO	-1630-06809	America/La_Paz
 BR	-0351-03225	America/Noronha	Atlantic islands
-BR	-0127-04829	America/Belem	Pará (east); Amapá
+BR	-0127-04829	America/Belem	Pará (east), Amapá
 BR	-0343-03830	America/Fortaleza	Brazil (northeast: MA, PI, CE, RN, PB)
 BR	-0803-03454	America/Recife	Pernambuco
 BR	-0712-04812	America/Araguaina	Tocantins
@@ -100,19 +101,19 @@ BR	-0958-06748	America/Rio_Branco	Acre
 BT	+2728+08939	Asia/Thimphu
 BY	+5354+02734	Europe/Minsk
 BZ	+1730-08812	America/Belize
-CA	+4734-05243	America/St_Johns	Newfoundland; Labrador (southeast)
-CA	+4439-06336	America/Halifax	Atlantic - NS (most areas); PE
+CA	+4734-05243	America/St_Johns	Newfoundland, Labrador (SE)
+CA	+4439-06336	America/Halifax	Atlantic - NS (most areas), PE
 CA	+4612-05957	America/Glace_Bay	Atlantic - NS (Cape Breton)
 CA	+4606-06447	America/Moncton	Atlantic - New Brunswick
 CA	+5320-06025	America/Goose_Bay	Atlantic - Labrador (most areas)
-CA,BS	+4339-07923	America/Toronto	Eastern - ON, QC (most areas)
+CA,BS	+4339-07923	America/Toronto	Eastern - ON & QC (most areas)
 CA	+6344-06828	America/Iqaluit	Eastern - NU (most areas)
-CA	+4953-09709	America/Winnipeg	Central - ON (west); Manitoba
+CA	+4953-09709	America/Winnipeg	Central - ON (west), Manitoba
 CA	+744144-0944945	America/Resolute	Central - NU (Resolute)
 CA	+624900-0920459	America/Rankin_Inlet	Central - NU (central)
 CA	+5024-10439	America/Regina	CST - SK (most areas)
 CA	+5017-10750	America/Swift_Current	CST - SK (midwest)
-CA	+5333-11328	America/Edmonton	Mountain - AB; BC (E); NT (E); SK (W)
+CA	+5333-11328	America/Edmonton	Mountain - AB, BC(E), NT(E), SK(W)
 CA	+690650-1050310	America/Cambridge_Bay	Mountain - NU (west)
 CA	+682059-1334300	America/Inuvik	Mountain - NT (west)
 CA	+5546-12014	America/Dawson_Creek	MST - BC (Dawson Cr, Ft St John)
@@ -127,7 +128,7 @@ CL	-3327-07040	America/Santiago	most of Chile
 CL	-5309-07055	America/Punta_Arenas	Region of Magallanes
 CL	-2709-10926	Pacific/Easter	Easter Island
 CN	+3114+12128	Asia/Shanghai	Beijing Time
-CN,AQ	+4348+08735	Asia/Urumqi	Xinjiang Time, Vostok
+CN	+4348+08735	Asia/Urumqi	Xinjiang Time
 CO	+0436-07405	America/Bogota
 CR	+0956-08405	America/Costa_Rica
 CU	+2308-08222	America/Havana
@@ -172,8 +173,8 @@ HT	+1832-07220	America/Port-au-Prince
 HU	+4730+01905	Europe/Budapest
 ID	-0610+10648	Asia/Jakarta	Java, Sumatra
 ID	-0002+10920	Asia/Pontianak	Borneo (west, central)
-ID	-0507+11924	Asia/Makassar	Borneo (east, south); Sulawesi/Celebes, Bali, Nusa Tengarra; Timor (west)
-ID	-0232+14042	Asia/Jayapura	New Guinea (West Papua / Irian Jaya); Malukus/Moluccas
+ID	-0507+11924	Asia/Makassar	Borneo (east, south), Sulawesi/Celebes, Bali, Nusa Tengarra, Timor (west)
+ID	-0232+14042	Asia/Jayapura	New Guinea (West Papua / Irian Jaya), Malukus/Moluccas
 IE	+5320-00615	Europe/Dublin
 IL	+314650+0351326	Asia/Jerusalem
 IN	+2232+08822	Asia/Kolkata
@@ -252,7 +253,7 @@ PK	+2452+06703	Asia/Karachi
 PL	+5215+02100	Europe/Warsaw
 PM	+4703-05620	America/Miquelon
 PN	-2504-13005	Pacific/Pitcairn
-PR,AG,CA,AI,AW,BL,BQ,CW,DM,GD,GP,KN,LC,MF,MS,SX,TT,VC,VG,VI	+182806-0660622	America/Puerto_Rico	AST
+PR,AG,CA,AI,AW,BL,BQ,CW,DM,GD,GP,KN,LC,MF,MS,SX,TT,VC,VG,VI	+182806-0660622	America/Puerto_Rico	AST - QC (Lower North Shore)
 PS	+3130+03428	Asia/Gaza	Gaza Strip
 PS	+313200+0350542	Asia/Hebron	West Bank
 PT	+3843-00908	Europe/Lisbon	Portugal (mainland)
@@ -288,7 +289,7 @@ RU	+4310+13156	Asia/Vladivostok	MSK+07 - Amur River
 RU	+643337+1431336	Asia/Ust-Nera	MSK+07 - Oymyakonsky
 RU	+5934+15048	Asia/Magadan	MSK+08 - Magadan
 RU	+4658+14242	Asia/Sakhalin	MSK+08 - Sakhalin Island
-RU	+6728+15343	Asia/Srednekolymsk	MSK+08 - Sakha (E); N Kuril Is
+RU	+6728+15343	Asia/Srednekolymsk	MSK+08 - Sakha (E), N Kuril Is
 RU	+5301+15839	Asia/Kamchatka	MSK+09 - Kamchatka
 RU	+6445+17729	Asia/Anadyr	MSK+09 - Bering Sea
 SA,AQ,KW,YE	+2438+04643	Asia/Riyadh	Syowa
@@ -330,7 +331,7 @@ US	+470659-1011757	America/North_Dakota/Center	Central - ND (Oliver)
 US	+465042-1012439	America/North_Dakota/New_Salem	Central - ND (Morton rural)
 US	+471551-1014640	America/North_Dakota/Beulah	Central - ND (Mercer)
 US	+394421-1045903	America/Denver	Mountain (most areas)
-US	+433649-1161209	America/Boise	Mountain - ID (south); OR (east)
+US	+433649-1161209	America/Boise	Mountain - ID (south), OR (east)
 US,CA	+332654-1120424	America/Phoenix	MST - AZ (most areas), Creston BC
 US	+340308-1181434	America/Los_Angeles	Pacific
 US	+611305-1495401	America/Anchorage	Alaska (most areas)
diff --git a/contrib/tzdata/zonenow.tab b/contrib/tzdata/zonenow.tab
new file mode 100644
index 000000000000..2dbe8f00d1b8
--- /dev/null
+++ b/contrib/tzdata/zonenow.tab
@@ -0,0 +1,301 @@
+# tzdb timezone descriptions, for users who do not care about old timestamps
+#
+# This file is in the public domain.
+#
+# From Paul Eggert (2023-12-18):
+# This file contains a table where each row stands for a timezone
+# where civil timestamps are predicted to agree from now on.
+# This file is like zone1970.tab (see zone1970.tab's coments),
+# but with the following changes:
+#
+# 1.  Each timezone corresponds to a set of clocks that are planned
+#     to agree from now on.  This is a larger set of clocks than in
+#     zone1970.tab, where each timezone's clocks must agree from 1970 on.
+# 2.  The first column is irrelevant and ignored.
+# 3.  The table is sorted in a different way:
+#     first by standard time UTC offset;
+#     then, if DST is used, by daylight saving UTC offset;
+#     then by time zone abbreviation.
+# 4.  Every timezone has a nonempty comments column, with wording
+#     distinguishing the timezone only from other timezones with the
+#     same UTC offset at some point during the year.
+#
+# The format of this table is experimental, and may change in future versions.
+#
+# This table is intended as an aid for users, to help them select timezones
+# appropriate for their practical needs.  It is not intended to take or
+# endorse any position on legal or territorial claims.
+#
+#XX	coordinates	TZ	comments
+#
+# -11 - SST
+XX	-1416-17042	Pacific/Pago_Pago	Midway; Samoa ("SST")
+#
+# -11
+XX	-1901-16955	Pacific/Niue	Niue
+#
+# -10 - HST
+XX	+211825-1575130	Pacific/Honolulu	Hawaii ("HST")
+#
+# -10
+XX	-1732-14934	Pacific/Tahiti	Tahiti; Cook Islands
+#
+# -10/-09 - HST / HDT (North America DST)
+XX	+515248-1763929	America/Adak	western Aleutians in Alaska ("HST/HDT")
+#
+# -09:30
+XX	-0900-13930	Pacific/Marquesas	Marquesas
+#
+# -09
+XX	-2308-13457	Pacific/Gambier	Gambier
+#
+# -09/-08 - AKST/AKDT (North America DST)
+XX	+611305-1495401	America/Anchorage	most of Alaska ("AKST/AKDT")
+#
+# -08
+XX	-2504-13005	Pacific/Pitcairn	Pitcairn
+#
+# -08/-07 - PST/PDT (North America DST)
+XX	+340308-1181434	America/Los_Angeles	Pacific ("PST/PDT") - US & Canada; Mexico near US border
+#
+# -07 - MST
+XX	+332654-1120424	America/Phoenix	Mountain Standard ("MST") - Arizona; western Mexico; Yukon
+#
+# -07/-06 - MST/MDT (North America DST)
+XX	+394421-1045903	America/Denver	Mountain ("MST/MDT") - US & Canada; Mexico near US border
+#
+# -06
+XX	-0054-08936	Pacific/Galapagos	Galápagos
+#
+# -06 - CST
+XX	+1924-09909	America/Mexico_City	Central Standard ("CST") - Saskatchewan; central Mexico; Central America
+#
+# -06/-05 (Chile DST)
+XX	-2709-10926	Pacific/Easter	Easter Island
+#
+# -06/-05 - CST/CDT (North America DST)
+XX	+415100-0873900	America/Chicago	Central ("CST/CDT") - US & Canada; Mexico near US border
+#
+# -05
+XX	-1203-07703	America/Lima	eastern South America
+#
+# -05 - EST
+XX	+175805-0764736	America/Jamaica	Eastern Standard ("EST") - Caymans; Jamaica; eastern Mexico; Panama
+#
+# -05/-04 - CST/CDT (Cuba DST)
+XX	+2308-08222	America/Havana	Cuba
+#
+# -05/-04 - EST/EDT (North America DST)
+XX	+404251-0740023	America/New_York	Eastern ("EST/EDT") - US & Canada
+#
+# -04
+XX	+1030-06656	America/Caracas	western South America
+#
+# -04 - AST
+XX	+1828-06954	America/Santo_Domingo	Atlantic Standard ("AST") - eastern Caribbean
+#
+# -04/-03 (Chile DST)
+XX	-3327-07040	America/Santiago	most of Chile
+#
+# -04/-03 (Paraguay DST)
+XX	-2516-05740	America/Asuncion	Paraguay
+#
+# -04/-03 - AST/ADT (North America DST)
+XX	+4439-06336	America/Halifax	Atlantic ("AST/ADT") - Canada; Bermuda
+#
+# -03:30/-02:30 - NST/NDT (North America DST)
+XX	+4734-05243	America/St_Johns	Newfoundland ("NST/NDT")
+#
+# -03
+XX	-2332-04637	America/Sao_Paulo	eastern South America
+#
+# -03/-02 (North America DST)
+XX	+4703-05620	America/Miquelon	St Pierre & Miquelon
+#
+# -02
+XX	-0351-03225	America/Noronha	Fernando de Noronha; South Georgia
+#
+# -02/-01 (EU DST)
+XX	+6411-05144	America/Nuuk	most of Greenland
+#
+# -01
+XX	+1455-02331	Atlantic/Cape_Verde	Cape Verde
+#
+# -01/+00 (EU DST)
+XX	+3744-02540	Atlantic/Azores	Azores
+# -01/+00 (EU DST) until 2024-03-31; then -02/-01 (EU DST)
+XX	+7029-02158	America/Scoresbysund	Ittoqqortoormiit
+#
+# +00 - GMT
+XX	+0519-00402	Africa/Abidjan	far western Africa; Iceland ("GMT")
+#
+# +00/+01 - GMT/BST (EU DST)
+XX	+513030-0000731	Europe/London	United Kingdom ("GMT/BST")
+#
+# +00/+01 - WET/WEST (EU DST)
+XX	+3843-00908	Europe/Lisbon	western Europe ("WET/WEST")
+#
+# +00/+02 - Troll DST
+XX	-720041+0023206	Antarctica/Troll	Troll Station in Antarctica
+#
+# +01 - CET
+XX	+3647+00303	Africa/Algiers	Algeria, Tunisia ("CET")
+#
+# +01 - WAT
+XX	+0627+00324	Africa/Lagos	western Africa ("WAT")
+#
+# +01/+00 - IST/GMT (EU DST in reverse)
+XX	+5320-00615	Europe/Dublin	Ireland ("IST/GMT")
+#
+# +01/+00 - (Morocco DST)
+XX	+3339-00735	Africa/Casablanca	Morocco
+#
+# +01/+02 - CET/CEST (EU DST)
+XX	+4852+00220	Europe/Paris	central Europe ("CET/CEST")
+#
+# +02 - CAT
+XX	-2558+03235	Africa/Maputo	central Africa ("CAT")
+#
+# +02 - EET
+XX	+3254+01311	Africa/Tripoli	Libya; Kaliningrad ("EET")
+#
+# +02 - SAST
+XX	-2615+02800	Africa/Johannesburg	southern Africa ("SAST")
+#
+# +02/+03 - EET/EEST (EU DST)
+XX	+3758+02343	Europe/Athens	eastern Europe ("EET/EEST")
+#
+# +02/+03 - EET/EEST (Egypt DST)
+XX	+3003+03115	Africa/Cairo	Egypt
+#
+# +02/+03 - EET/EEST (Lebanon DST)
+XX	+3353+03530	Asia/Beirut	Lebanon
+#
+# +02/+03 - EET/EEST (Moldova DST)
+XX	+4700+02850	Europe/Chisinau	Moldova
+#
+# +02/+03 - EET/EEST (Palestine DST)
+XX	+3130+03428	Asia/Gaza	Palestine
+#
+# +02/+03 - IST/IDT (Israel DST)
+XX	+314650+0351326	Asia/Jerusalem	Israel
+#
+# +03
+XX	+4101+02858	Europe/Istanbul	Near East; Belarus
+#
+# +03 - EAT
+XX	-0117+03649	Africa/Nairobi	eastern Africa ("EAT")
+#
+# +03 - MSK
+XX	+554521+0373704	Europe/Moscow	Moscow ("MSK")
+#
+# +03:30
+XX	+3540+05126	Asia/Tehran	Iran
+#
+# +04
+XX	+2518+05518	Asia/Dubai	Russia; Caucasus; Persian Gulf; Seychelles; Réunion
+#
+# +04:30
+XX	+3431+06912	Asia/Kabul	Afghanistan
+#
+# +05
+XX	+4120+06918	Asia/Tashkent	Russia; Tajikistan; Turkmenistan; Uzbekistan; Maldives
+#
+# +05 - PKT
+XX	+2452+06703	Asia/Karachi	Pakistan ("PKT")
+#
+# +05:30
+XX	+0656+07951	Asia/Colombo	Sri Lanka
+#
+# +05:30 - IST
+XX	+2232+08822	Asia/Kolkata	India ("IST")
+#
+# +05:45
+XX	+2743+08519	Asia/Kathmandu	Nepal
+#
+# +06
+XX	+2343+09025	Asia/Dhaka	Russia; Kyrgyzstan; Bhutan; Bangladesh; Chagos
+#
+# +06:30
+XX	+1647+09610	Asia/Yangon	Myanmar; Cocos
+#
+# +07
+XX	+1345+10031	Asia/Bangkok	Russia; Indochina; Christmas Island
+#
+# +07 - WIB
+XX	-0610+10648	Asia/Jakarta	Indonesia ("WIB")
+#
+# +08
+XX	+0117+10351	Asia/Singapore	Russia; Brunei; Malaysia; Singapore
+#
+# +08 - AWST
+XX	-3157+11551	Australia/Perth	Western Australia ("AWST")
+#
+# +08 - CST
+XX	+3114+12128	Asia/Shanghai	China ("CST")
+#
+# +08 - HKT
+XX	+2217+11409	Asia/Hong_Kong	Hong Kong ("HKT")
+#
+# +08 - PHT
+XX	+1435+12100	Asia/Manila	Philippines ("PHT")
+#
+# +08 - WITA
+XX	-0507+11924	Asia/Makassar	Indonesia ("WITA")
+#
+# +08:45
+XX	-3143+12852	Australia/Eucla	Eucla
+#
+# +09
+XX	+5203+11328	Asia/Chita	Russia; Palau; East Timor
+#
+# +09 - JST
+XX	+353916+1394441	Asia/Tokyo	Japan ("JST")
+#
+# +09 - KST
+XX	+3733+12658	Asia/Seoul	Korea ("KST")
+#
+# +09 - WIT
+XX	-0232+14042	Asia/Jayapura	Indonesia ("WIT")
+#
+# +09:30 - ACST
+XX	-1228+13050	Australia/Darwin	Northern Territory ("ACST")
+#
+# +09:30/+10:30 - ACST/ACDT (Australia DST)
+XX	-3455+13835	Australia/Adelaide	South Australia ("ACST/ACDT")
+#
+# +10
+XX	+4310+13156	Asia/Vladivostok	Russia; Yap; Chuuk; Papua New Guinea; Dumont d'Urville
+#
+# +10 - AEST
+XX	-2728+15302	Australia/Brisbane	Queensland ("AEST")
+#
+# +10 - ChST
+XX	+1328+14445	Pacific/Guam	Mariana Islands ("ChST")
+#
+# +10/+11 - AEST/AEDT (Australia DST)
+XX	-3352+15113	Australia/Sydney	southeast Australia ("AEST/AEDT")
+#
+# +10:30/+11
+XX	-3133+15905	Australia/Lord_Howe	Lord Howe Island
+#
+# +11
+XX	-0613+15534	Pacific/Bougainville	Russia; Kosrae; Bougainville; Solomons
+#
+# +11/+12 (Australia DST)
+XX	-2903+16758	Pacific/Norfolk	Norfolk Island
+#
+# +12
+XX	+5301+15839	Asia/Kamchatka	Russia; Tuvalu; Fiji; etc.
+#
+# +12/+13 (New Zealand DST)
+XX	-3652+17446	Pacific/Auckland	New Zealand ("NZST/NZDT")
+#
+# +12:45/+13:45 (Chatham DST)
+XX	-4357-17633	Pacific/Chatham	Chatham Islands
+#
+# +13
+XX	-210800-1751200	Pacific/Tongatapu	Kanton; Tokelau; Samoa (western); Tonga
+#
+# +14
+XX	+0152-15720	Pacific/Kiritimati	Kiritimati