Import tzdata 2023avendor/tzdata/tzdata2023a

21 files changed, 505 insertions, 254 deletions

diff --git a/CONTRIBUTING b/CONTRIBUTING
index 4c0f56a50265..6d800e4c03a3 100644
--- a/CONTRIBUTING
+++ b/CONTRIBUTING
@@ -18,7 +18,7 @@ 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"
 <https://www.iana.org/time-zones/repository/theory.html>.
diff --git a/Makefile b/Makefile
index afb9d538a203..6edc73cc6ffb 100644
--- a/Makefile
+++ b/Makefile
@@ -35,22 +35,14 @@ DATAFORM=		main
 
 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 # Any other value for POSIXRULES is obsolete and should not be relied on, as: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).
@@ -63,7 +55,7 @@ LOCALTIME=	Factory
 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.
@@ -211,7 +203,7 @@ LDLIBS=
 #  -DHAVE_DECL_ENVIRON if <unistd.h> declares 'environ'
 #  -DHAVE_DECL_TIMEGM=0 if <time.h> does not declare timegm
 #  -DHAVE_DIRECT_H if mkdir needs <direct.h> (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),
@@ -220,7 +212,7 @@ LDLIBS=
 #  -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 <inttypes.h> does not work*
+#  -DHAVE_INTTYPES_H=0 if <inttypes.h> 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
@@ -229,22 +221,24 @@ LDLIBS=
 #  -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 <stdckdint.h> nor substitutes like
 #	__builtin_add_overflow work*
-#  -DHAVE_STDINT_H=0 if <stdint.h> does not work*
+#  -DHAVE_STDINT_H=0 if <stdint.h> does not work*+
 #  -DHAVE_STRFTIME_L if <time.h> 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 <sys/stat.h> does not work*
 #  -DHAVE_TZSET=0 if your system lacks a tzset function
 #  -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+
 #  -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;
@@ -256,7 +250,13 @@ 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 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
@@ -273,6 +273,8 @@ LDLIBS=
 #  $(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 = \
@@ -363,7 +365,7 @@ GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \
 #	-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
@@ -455,16 +457,13 @@ 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:]
@@ -833,7 +832,7 @@ check_slashed_abbrs: $(TDATA_TO_CHECK)
 
 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
diff --git a/NEWS b/NEWS
index 701e490e4834..cd5cafe3f3c6 100644
--- a/NEWS
+++ b/NEWS
@@ -1,5 +1,100 @@
 News for the tz database
 
+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:
@@ -596,7 +691,7 @@ Release 2021b - 2021-09-24 16:23:00 -0700
     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
@@ -616,7 +711,7 @@ Release 2021b - 2021-09-24 16:23:00 -0700
     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
@@ -670,7 +765,7 @@ Release 2021b - 2021-09-24 16:23:00 -0700
     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
@@ -691,7 +786,7 @@ Release 2021b - 2021-09-24 16:23:00 -0700
     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.)
@@ -2311,7 +2406,7 @@ Release 2016g - 2016-09-13 08:56:38 -0700
     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.)
@@ -2333,7 +2428,7 @@ Release 2016g - 2016-09-13 08:56:38 -0700
     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'.
 
@@ -2964,7 +3059,7 @@ Release 2014i - 2014-10-21 22:04:57 -0700
 
     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
@@ -3056,7 +3151,7 @@ Release 2014h - 2014-09-25 18:59:03 -0700
 
   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
 
@@ -3557,7 +3652,7 @@ Release 2014a - 2014-03-07 23:30:29 -0800
 
   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
@@ -3811,7 +3906,7 @@ Release 2013e - 2013-09-19 23:50:04 -0700
     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
@@ -3819,7 +3914,7 @@ Release 2013e - 2013-09-19 23:50:04 -0700
 
     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
@@ -3908,13 +4003,13 @@ Release 2013e - 2013-09-19 23:50:04 -0700
 
     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
@@ -4098,7 +4193,7 @@ Release 2013c - 2013-04-19 16:17:40 -0700
     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.)
 
 
@@ -5322,7 +5417,7 @@ Release data1998g - 1998-08-11 03:28:35 -0000
 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.
 
 
diff --git a/africa b/africa
index cfb9283c045d..6cf4e39c8c45 100644
--- a/africa
+++ b/africa
@@ -321,6 +321,14 @@ Rule	Egypt	2007	only	-	Sep	Thu>=1	24:00	0	-
 # From Mina Samuel (2016-07-04):
 # Egyptian government took the decision to cancel the DST,
 
+# From Ahmad ElDardiry (2023-03-01):
+# Egypt officially announced today that daylight savings will be
+# applied from last Friday of April to last Thursday of October.
+# From Paul Eggert (2023-03-01):
+# Assume transitions are at 00:00 and 24:00 respectively.
+# From Amir Adib (2023-03-07):
+# https://www.facebook.com/EgyptianCabinet/posts/638829614954129/
+
 Rule	Egypt	2008	only	-	Aug	lastThu	24:00	0	-
 Rule	Egypt	2009	only	-	Aug	20	24:00	0	-
 Rule	Egypt	2010	only	-	Aug	10	24:00	0	-
@@ -330,6 +338,8 @@ Rule	Egypt	2014	only	-	May	15	24:00	1:00	S
 Rule	Egypt	2014	only	-	Jun	26	24:00	0	-
 Rule	Egypt	2014	only	-	Jul	31	24:00	1:00	S
 Rule	Egypt	2014	only	-	Sep	lastThu	24:00	0	-
+Rule	Egypt	2023	max	-	Apr	lastFri	 0:00	1:00	S
+Rule	Egypt	2023	max	-	Oct	lastThu	24:00	0	-
 
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
 		#STDOFF	2:05:08.9
@@ -429,7 +439,7 @@ Zone	Africa/Nairobi	2:27:16	-	LMT	1908 May
 # President William R. Tolbert, Jr., July 23, 1971-July 31, 1972.
 # Monrovia: Executive Mansion.
 #
-# Use the abbreviation "MMT" before 1972, as the more-accurate numeric
+# Use the abbreviation "MMT" before 1972, as the more accurate numeric
 # abbreviation "-004430" would be one byte over the POSIX limit.
 #
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
@@ -566,8 +576,8 @@ Zone	Africa/Tripoli	0:52:44 -	LMT	1920
 # DST the coming summer...
 #
 # Some sources, in French:
-# http://www.defimedia.info/news/946/Rashid-Beebeejaun-:-%C2%AB-L%E2%80%99heure-d%E2%80%99%C3%A9t%C3%A9-ne-sera-pas-appliqu%C3%A9e-cette-ann%C3%A9e-%C2%BB
-# http://lexpress.mu/Story/3398~Beebeejaun---Les-objectifs-d-%C3%A9conomie-d-%C3%A9nergie-de-l-heure-d-%C3%A9t%C3%A9-ont-%C3%A9t%C3%A9-atteints-
+# http://www.defimedia.info/news/946/Rashid-Beebeejaun-:-«-L%E2%80%99heure-d%E2%80%99été-ne-sera-pas-appliquée-cette-année-»
+# http://lexpress.mu/Story/3398~Beebeejaun---Les-objectifs-d-économie-d-énergie-de-l-heure-d-été-ont-été-atteints-
 #
 # Our wrap-up:
 # https://www.timeanddate.com/news/time/mauritius-dst-will-not-repeat.html
@@ -698,7 +708,7 @@ Zone Indian/Mauritius	3:50:00 -	LMT	1907 # Port Louis
 # More articles in the press
 # https://www.yabiladi.com/articles/details/5058/secret-l-heure-d-ete-maroc-leve.html
 # http://www.lematin.ma/Actualite/Express/Article.asp?id=148923
-# http://www.lavieeco.com/actualite/Le-Maroc-passe-sur-GMT%2B1-a-partir-de-dim
+# http://www.lavieeco.com/actualite/Le-Maroc-passe-sur-GMT+1-a-partir-de-dim
 
 # From Petr Machata (2011-03-30):
 # They have it written in English here:
@@ -713,7 +723,7 @@ Zone Indian/Mauritius	3:50:00 -	LMT	1907 # Port Louis
 # According to Infomédiaire web site from Morocco (infomediaire.ma),
 # on March 9, 2012, (in French) Heure légale:
 # Le Maroc adopte officiellement l'heure d'été
-# http://www.infomediaire.ma/news/maroc/heure-l%C3%A9gale-le-maroc-adopte-officiellement-lheure-d%C3%A9t%C3%A9
+# http://www.infomediaire.ma/news/maroc/heure-légale-le-maroc-adopte-officiellement-lheure-dété
 # Governing Council adopted draft decree, that Morocco DST starts on
 # the last Sunday of March (March 25, 2012) and ends on
 # last Sunday of September (September 30, 2012)
@@ -837,19 +847,28 @@ Zone Indian/Mauritius	3:50:00 -	LMT	1907 # Port Louis
 # Friday or Saturday (and so the 2 days off are on a weekend), the next time
 # shift will be the next weekend.
 #
-# From Paul Eggert (2020-05-31):
+# From Milamber (2021-03-31, 2022-03-10):
+# https://www.mmsp.gov.ma/fr/actualites.aspx?id=2076
+# https://www.ecoactu.ma/horaires-administration-ramadan-gmtheure-gmt-a-partir-de-dimanche-27-mars/
+#
+# From Milamber (2023-03-14, 2023-03-15):
+# The return to legal GMT time will take place this Sunday, March 19 at 3 a.m.
+# ... the return to GMT+1 will be made on Sunday April 23, 2023 at 2 a.m.
+# https://www.mmsp.gov.ma/fr/actualites/passage-à-l%E2%80%99heure-gmt-à-partir-du-dimanche-19-mars-2023
+#
+# From Paul Eggert (2023-03-14):
 # For now, guess that in the future Morocco will fall back at 03:00
 # the last Sunday before Ramadan, and spring forward at 02:00 the
-# first Sunday after two days after Ramadan.  To implement this,
+# first Sunday after one day after Ramadan.  To implement this,
 # transition dates and times for 2019 through 2087 were determined by
-# running the following program under GNU Emacs 26.3.  (This algorithm
+# running the following program under GNU Emacs 28.2.  (This algorithm
 # also produces the correct transition dates for 2016 through 2018,
 # though the times differ due to Morocco's time zone change in 2018.)
 # (let ((islamic-year 1440))
 #   (require 'cal-islam)
 #   (while (< islamic-year 1511)
 #     (let ((a (calendar-islamic-to-absolute (list 9 1 islamic-year)))
-#           (b (+ 2 (calendar-islamic-to-absolute (list 10 1 islamic-year))))
+#           (b (+ 1 (calendar-islamic-to-absolute (list 10 1 islamic-year))))
 #           (sunday 0))
 #       (while (/= sunday (mod (setq a (1- a)) 7)))
 #       (while (/= sunday (mod b 7))
@@ -863,10 +882,6 @@ Zone Indian/Mauritius	3:50:00 -	LMT	1907 # Port Louis
 #         (car (cdr (cdr a))) (calendar-month-name (car a) t) (car (cdr a))
 #         (car (cdr (cdr b))) (calendar-month-name (car b) t) (car (cdr b)))))
 #     (setq islamic-year (+ 1 islamic-year))))
-#
-# From Milamber (2021-03-31, 2022-03-10), confirming these predictions:
-# https://www.mmsp.gov.ma/fr/actualites.aspx?id=2076
-# https://www.ecoactu.ma/horaires-administration-ramadan-gmtheure-gmt-a-partir-de-dimanche-27-mars/
 
 # Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Morocco	1939	only	-	Sep	12	 0:00	1:00	-
@@ -919,7 +934,7 @@ Rule	Morocco	2021	only	-	May	16	 2:00	0	-
 Rule	Morocco	2022	only	-	Mar	27	 3:00	-1:00	-
 Rule	Morocco	2022	only	-	May	 8	 2:00	0	-
 Rule	Morocco	2023	only	-	Mar	19	 3:00	-1:00	-
-Rule	Morocco	2023	only	-	Apr	30	 2:00	0	-
+Rule	Morocco	2023	only	-	Apr	23	 2:00	0	-
 Rule	Morocco	2024	only	-	Mar	10	 3:00	-1:00	-
 Rule	Morocco	2024	only	-	Apr	14	 2:00	0	-
 Rule	Morocco	2025	only	-	Feb	23	 3:00	-1:00	-
@@ -935,7 +950,7 @@ Rule	Morocco	2029	only	-	Feb	18	 2:00	0	-
 Rule	Morocco	2029	only	-	Dec	30	 3:00	-1:00	-
 Rule	Morocco	2030	only	-	Feb	10	 2:00	0	-
 Rule	Morocco	2030	only	-	Dec	22	 3:00	-1:00	-
-Rule	Morocco	2031	only	-	Feb	 2	 2:00	0	-
+Rule	Morocco	2031	only	-	Jan	26	 2:00	0	-
 Rule	Morocco	2031	only	-	Dec	14	 3:00	-1:00	-
 Rule	Morocco	2032	only	-	Jan	18	 2:00	0	-
 Rule	Morocco	2032	only	-	Nov	28	 3:00	-1:00	-
@@ -951,7 +966,7 @@ Rule	Morocco	2036	only	-	Nov	23	 2:00	0	-
 Rule	Morocco	2037	only	-	Oct	 4	 3:00	-1:00	-
 Rule	Morocco	2037	only	-	Nov	15	 2:00	0	-
 Rule	Morocco	2038	only	-	Sep	26	 3:00	-1:00	-
-Rule	Morocco	2038	only	-	Nov	 7	 2:00	0	-
+Rule	Morocco	2038	only	-	Oct	31	 2:00	0	-
 Rule	Morocco	2039	only	-	Sep	18	 3:00	-1:00	-
 Rule	Morocco	2039	only	-	Oct	23	 2:00	0	-
 Rule	Morocco	2040	only	-	Sep	 2	 3:00	-1:00	-
@@ -967,7 +982,7 @@ Rule	Morocco	2044	only	-	Aug	28	 2:00	0	-
 Rule	Morocco	2045	only	-	Jul	 9	 3:00	-1:00	-
 Rule	Morocco	2045	only	-	Aug	20	 2:00	0	-
 Rule	Morocco	2046	only	-	Jul	 1	 3:00	-1:00	-
-Rule	Morocco	2046	only	-	Aug	12	 2:00	0	-
+Rule	Morocco	2046	only	-	Aug	 5	 2:00	0	-
 Rule	Morocco	2047	only	-	Jun	23	 3:00	-1:00	-
 Rule	Morocco	2047	only	-	Jul	28	 2:00	0	-
 Rule	Morocco	2048	only	-	Jun	 7	 3:00	-1:00	-
@@ -983,7 +998,7 @@ Rule	Morocco	2052	only	-	Jun	 2	 2:00	0	-
 Rule	Morocco	2053	only	-	Apr	13	 3:00	-1:00	-
 Rule	Morocco	2053	only	-	May	25	 2:00	0	-
 Rule	Morocco	2054	only	-	Apr	 5	 3:00	-1:00	-
-Rule	Morocco	2054	only	-	May	17	 2:00	0	-
+Rule	Morocco	2054	only	-	May	10	 2:00	0	-
 Rule	Morocco	2055	only	-	Mar	28	 3:00	-1:00	-
 Rule	Morocco	2055	only	-	May	 2	 2:00	0	-
 Rule	Morocco	2056	only	-	Mar	12	 3:00	-1:00	-
@@ -999,7 +1014,7 @@ Rule	Morocco	2060	only	-	Mar	 7	 2:00	0	-
 Rule	Morocco	2061	only	-	Jan	16	 3:00	-1:00	-
 Rule	Morocco	2061	only	-	Feb	27	 2:00	0	-
 Rule	Morocco	2062	only	-	Jan	 8	 3:00	-1:00	-
-Rule	Morocco	2062	only	-	Feb	19	 2:00	0	-
+Rule	Morocco	2062	only	-	Feb	12	 2:00	0	-
 Rule	Morocco	2062	only	-	Dec	31	 3:00	-1:00	-
 Rule	Morocco	2063	only	-	Feb	 4	 2:00	0	-
 Rule	Morocco	2063	only	-	Dec	16	 3:00	-1:00	-
@@ -1015,7 +1030,7 @@ Rule	Morocco	2067	only	-	Dec	11	 2:00	0	-
 Rule	Morocco	2068	only	-	Oct	21	 3:00	-1:00	-
 Rule	Morocco	2068	only	-	Dec	 2	 2:00	0	-
 Rule	Morocco	2069	only	-	Oct	13	 3:00	-1:00	-
-Rule	Morocco	2069	only	-	Nov	24	 2:00	0	-
+Rule	Morocco	2069	only	-	Nov	17	 2:00	0	-
 Rule	Morocco	2070	only	-	Oct	 5	 3:00	-1:00	-
 Rule	Morocco	2070	only	-	Nov	 9	 2:00	0	-
 Rule	Morocco	2071	only	-	Sep	20	 3:00	-1:00	-
@@ -1031,7 +1046,7 @@ Rule	Morocco	2075	only	-	Sep	15	 2:00	0	-
 Rule	Morocco	2076	only	-	Jul	26	 3:00	-1:00	-
 Rule	Morocco	2076	only	-	Sep	 6	 2:00	0	-
 Rule	Morocco	2077	only	-	Jul	18	 3:00	-1:00	-
-Rule	Morocco	2077	only	-	Aug	29	 2:00	0	-
+Rule	Morocco	2077	only	-	Aug	22	 2:00	0	-
 Rule	Morocco	2078	only	-	Jul	10	 3:00	-1:00	-
 Rule	Morocco	2078	only	-	Aug	14	 2:00	0	-
 Rule	Morocco	2079	only	-	Jun	25	 3:00	-1:00	-
@@ -1041,13 +1056,13 @@ Rule	Morocco	2080	only	-	Jul	21	 2:00	0	-
 Rule	Morocco	2081	only	-	Jun	 1	 3:00	-1:00	-
 Rule	Morocco	2081	only	-	Jul	13	 2:00	0	-
 Rule	Morocco	2082	only	-	May	24	 3:00	-1:00	-
-Rule	Morocco	2082	only	-	Jul	 5	 2:00	0	-
+Rule	Morocco	2082	only	-	Jun	28	 2:00	0	-
 Rule	Morocco	2083	only	-	May	16	 3:00	-1:00	-
 Rule	Morocco	2083	only	-	Jun	20	 2:00	0	-
 Rule	Morocco	2084	only	-	Apr	30	 3:00	-1:00	-
 Rule	Morocco	2084	only	-	Jun	11	 2:00	0	-
 Rule	Morocco	2085	only	-	Apr	22	 3:00	-1:00	-
-Rule	Morocco	2085	only	-	Jun	 3	 2:00	0	-
+Rule	Morocco	2085	only	-	May	27	 2:00	0	-
 Rule	Morocco	2086	only	-	Apr	14	 3:00	-1:00	-
 Rule	Morocco	2086	only	-	May	19	 2:00	0	-
 Rule	Morocco	2087	only	-	Mar	30	 3:00	-1:00	-
@@ -1190,15 +1205,15 @@ Zone	Africa/Windhoek	1:08:24 -	LMT	1892 Feb 8
 # From P Chan (2020-12-03):
 # GMT was adopted as the standard time of Lagos on 1905-07-01.
 # Lagos Weekly Record, 1905-06-24, p 3
-# http://ddsnext.crl.edu/titles/31558#?c=0&m=668&s=0&cv=2&r=0&xywh=1446%2C5221%2C1931%2C1235
+# http://ddsnext.crl.edu/titles/31558#?c=0&m=668&s=0&cv=2&r=0&xywh=1446,5221,1931,1235
 # says "It is officially notified that on and after the 1st of July 1905
-# Greenwich Mean Solar Time will be adopted thought the Colony and
+# Greenwich Mean Solar Time will be adopted throughout the Colony and
 # Protectorate, and that it will be necessary to put all clocks 13 minutes and
 # 35 seconds back, recording local mean time."
 #
 # It seemed that Lagos returned to LMT on 1908-07-01.
 # [The Lagos Standard], 1908-07-01, p 5
-# http://ddsnext.crl.edu/titles/31556#?c=0&m=78&s=0&cv=4&r=0&xywh=-92%2C3590%2C3944%2C2523
+# http://ddsnext.crl.edu/titles/31556#?c=0&m=78&s=0&cv=4&r=0&xywh=-92,3590,3944,2523
 # says "Scarcely have the people become accustomed to this new time, when
 # another official notice has now appeared announcing that from and after the
 # 1st July next, return will be made to local mean time."
@@ -1210,7 +1225,7 @@ Zone	Africa/Windhoek	1:08:24 -	LMT	1892 Feb 8
 # https://libsysdigi.library.illinois.edu/ilharvest/Africana/Books2011-05/3064634/3064634_1914/3064634_1914_opt.pdf#page=27
 # "On January 1st [1914], a universal standard time for Nigeria was adopted,
 # viz., half an hour fast on Greenwich mean time, corresponding to the meridian
-# 7 [degrees] 30' E. long."
+# 7° 30' E. long."
 # Lloyd's Register of Shipping (1915) says "Hitherto the time observed in Lagos
 # was the local mean time. On 1st January, 1914, standard time for the whole of
 # Nigeria was introduced ... Lagos time has been advanced about 16 minutes
@@ -1228,7 +1243,7 @@ Zone	Africa/Windhoek	1:08:24 -	LMT	1892 Feb 8
 # The Lagos Weekly Record, 1919-09-20, p 3 details discussion on the first
 # reading of this Bill by the Legislative Council of the Colony of Nigeria on
 # Thursday 1919-08-28:
-# http://ddsnext.crl.edu/titles/31558?terms&item_id=303484#?m=1118&c=1&s=0&cv=2&r=0&xywh=1261%2C3408%2C2994%2C1915
+# http://ddsnext.crl.edu/titles/31558?terms&item_id=303484#?m=1118&c=1&s=0&cv=2&r=0&xywh=1261,3408,2994,1915
 # "The proposal is that the Globe should be divided into twelve zones East and
 # West of Greenwich, of one hour each, Nigeria falling into the zone with a
 # standard of one hour fast on Greenwich Mean Time.  Nigeria standard time is
diff --git a/antarctica b/antarctica
index f02755ae856f..fc603e9996de 100644
--- a/antarctica
+++ b/antarctica
@@ -292,7 +292,7 @@ Zone Antarctica/Rothera	0	-	-00	1976 Dec  1
 # but that he found it more convenient to keep GMT+12
 # as supplies for the station were coming from McMurdo Sound,
 # which was on GMT+12 because New Zealand was on GMT+12 all year
-# at that time (1957).  (Source: Siple's book 90 Degrees South.)
+# at that time (1957).  (Source: Siple's book 90° South.)
 #
 # From Susan Smith
 # http://www.cybertours.com/whs/pole10.html
diff --git a/asia b/asia
index 199e6ad6adc3..25592db89e83 100644
--- a/asia
+++ b/asia
@@ -2954,7 +2954,7 @@ Zone	Asia/Kathmandu	5:41:16 -	LMT	1920
 # 9pm and moving clocks forward by one hour for the next three months. ...."
 #
 # http://www.worldtimezone.com/dst_news/dst_news_pakistan01.html
-# http://www.dailytimes.com.pk/default.asp?page=2008%5C05%5C15%5Cstory_15-5-2008_pg1_4
+# http://www.dailytimes.com.pk/default.asp?page=2008\05\15\story_15-5-2008_pg1_4
 
 # From Arthur David Olson (2008-05-19):
 # XXX--midnight transitions is a guess; 2008 only is a guess.
@@ -3277,7 +3277,7 @@ Zone	Asia/Karachi	4:28:12 -	LMT	1907
 # Some of many sources in Arabic:
 # http://www.samanews.com/index.php?act=Show&id=122638
 #
-# http://safa.ps/details/news/74352/%D8%A8%D8%AF%D8%A1-%D8%A7%D9%84%D8%AA%D9%88%D9%82%D9%8A%D8%AA-%D8%A7%D9%84%D8%B5%D9%8A%D9%81%D9%8A-%D8%A8%D8%A7%D9%84%D8%B6%D9%81%D8%A9-%D9%88%D8%BA%D8%B2%D8%A9-%D9%84%D9%8A%D9%84%D8%A9-%D8%A7%D9%84%D8%AC%D9%85%D8%B9%D8%A9.html
+# http://safa.ps/details/news/74352/بدء-التوقيت-الصيفي-بالضفة-وغزة-ليلة-الجمعة.html
 #
 # Our brief summary:
 # https://www.timeanddate.com/news/time/gaza-west-bank-dst-2012.html
@@ -3287,7 +3287,7 @@ Zone	Asia/Karachi	4:28:12 -	LMT	1907
 # time from midnight on Friday, March 29, 2013" (translated).
 # [These are in Arabic and are for Gaza and for Ramallah, respectively.]
 # http://www.samanews.com/index.php?act=Show&id=154120
-# http://safa.ps/details/news/99844/%D8%B1%D8%A7%D9%85-%D8%A7%D9%84%D9%84%D9%87-%D8%A8%D8%AF%D8%A1-%D8%A7%D9%84%D8%AA%D9%88%D9%82%D9%8A%D8%AA-%D8%A7%D9%84%D8%B5%D9%8A%D9%81%D9%8A-29-%D8%A7%D9%84%D8%AC%D8%A7%D8%B1%D9%8A.html
+# http://safa.ps/details/news/99844/رام-الله-بدء-التوقيت-الصيفي-29-الجاري.html
 
 # From Steffen Thorsen (2013-09-24):
 # The Gaza and West Bank are ending DST Thursday at midnight
@@ -3385,9 +3385,41 @@ Zone	Asia/Karachi	4:28:12 -	LMT	1907
 # (2022-08-31): ... the Saturday before the last Sunday in March and October
 # at 2:00 AM ,for the years from 2023 to 2026.
 # (2022-09-05): https://mtit.pna.ps/Site/New/1453
-#
-# From Paul Eggert (2022-08-31):
-# For now, assume that this rule will also be used after 2026.
+
+# 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 Paul Eggert (2023-03-22):
+# For now, guess that spring and fall transitions will normally
+# continue to use 2022's rules, that during DST Palestine will switch
+# to standard time at 02:00 the last Saturday before Ramadan and back
+# to DST at 02:00 the first Saturday after Ramadan, and that
+# if the normal spring-forward or fall-back transition occurs during
+# Ramadan the former is delayed and the latter advanced.
+# To implement this, I predicted Ramadan-oriented transition dates for
+# 2023 through 2086 by running the following program under GNU Emacs 28.2,
+# with the results integrated by hand into the table below.
+# Predictions after 2086 are approximated without Ramadan.
+#
+# (let ((islamic-year 1444))
+#   (require 'cal-islam)
+#   (while (< islamic-year 1510)
+#     (let ((a (calendar-islamic-to-absolute (list 9 1 islamic-year)))
+#           (b (+ 1 (calendar-islamic-to-absolute (list 10 1 islamic-year))))
+#           (saturday 6))
+#       (while (/= saturday (mod (setq a (1- a)) 7)))
+#       (while (/= saturday (mod b 7))
+#         (setq b (1+ b)))
+#       (setq a (calendar-gregorian-from-absolute a))
+#       (setq b (calendar-gregorian-from-absolute b))
+#       (insert
+#        (format
+#         (concat "Rule Palestine\t%d\tonly\t-\t%s\t%2d\t2:00\t0\t-\n"
+#                 "Rule Palestine\t%d\tonly\t-\t%s\t%2d\t2:00\t1:00\tS\n")
+#         (car (cdr (cdr a))) (calendar-month-name (car a) t) (car (cdr a))
+#         (car (cdr (cdr b))) (calendar-month-name (car b) t) (car (cdr b)))))
+#     (setq islamic-year (+ 1 islamic-year))))
 
 # Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule EgyptAsia	1957	only	-	May	10	0:00	1:00	S
@@ -3427,8 +3459,86 @@ Rule Palestine	2020	2021	-	Mar	Sat<=30	0:00	1:00	S
 Rule Palestine	2020	only	-	Oct	24	1:00	0	-
 Rule Palestine	2021	only	-	Oct	29	1:00	0	-
 Rule Palestine	2022	only	-	Mar	27	0:00	1:00	S
-Rule Palestine	2022	max	-	Oct	Sat<=30	2:00	0	-
-Rule Palestine	2023	max	-	Mar	Sat<=30	2:00	1:00	S
+Rule Palestine	2022	2035	-	Oct	Sat<=30	2:00	0	-
+Rule Palestine	2023	only	-	Apr	29	2:00	1:00	S
+Rule Palestine	2024	only	-	Apr	13	2:00	1:00	S
+Rule Palestine	2025	only	-	Apr	 5	2:00	1:00	S
+Rule Palestine	2026	2054	-	Mar	Sat<=30	2:00	1:00	S
+Rule Palestine	2036	only	-	Oct	18	2:00	0	-
+Rule Palestine	2037	only	-	Oct	10	2:00	0	-
+Rule Palestine	2038	only	-	Sep	25	2:00	0	-
+Rule Palestine	2039	only	-	Sep	17	2:00	0	-
+Rule Palestine	2039	only	-	Oct	22	2:00	1:00	S
+Rule Palestine	2039	2067	-	Oct	Sat<=30	2:00	0	-
+Rule Palestine	2040	only	-	Sep	 1	2:00	0	-
+Rule Palestine	2040	only	-	Oct	13	2:00	1:00	S
+Rule Palestine	2041	only	-	Aug	24	2:00	0	-
+Rule Palestine	2041	only	-	Sep	28	2:00	1:00	S
+Rule Palestine	2042	only	-	Aug	16	2:00	0	-
+Rule Palestine	2042	only	-	Sep	20	2:00	1:00	S
+Rule Palestine	2043	only	-	Aug	 1	2:00	0	-
+Rule Palestine	2043	only	-	Sep	12	2:00	1:00	S
+Rule Palestine	2044	only	-	Jul	23	2:00	0	-
+Rule Palestine	2044	only	-	Aug	27	2:00	1:00	S
+Rule Palestine	2045	only	-	Jul	15	2:00	0	-
+Rule Palestine	2045	only	-	Aug	19	2:00	1:00	S
+Rule Palestine	2046	only	-	Jun	30	2:00	0	-
+Rule Palestine	2046	only	-	Aug	11	2:00	1:00	S
+Rule Palestine	2047	only	-	Jun	22	2:00	0	-
+Rule Palestine	2047	only	-	Jul	27	2:00	1:00	S
+Rule Palestine	2048	only	-	Jun	 6	2:00	0	-
+Rule Palestine	2048	only	-	Jul	18	2:00	1:00	S
+Rule Palestine	2049	only	-	May	29	2:00	0	-
+Rule Palestine	2049	only	-	Jul	 3	2:00	1:00	S
+Rule Palestine	2050	only	-	May	21	2:00	0	-
+Rule Palestine	2050	only	-	Jun	25	2:00	1:00	S
+Rule Palestine	2051	only	-	May	 6	2:00	0	-
+Rule Palestine	2051	only	-	Jun	17	2:00	1:00	S
+Rule Palestine	2052	only	-	Apr	27	2:00	0	-
+Rule Palestine	2052	only	-	Jun	 1	2:00	1:00	S
+Rule Palestine	2053	only	-	Apr	12	2:00	0	-
+Rule Palestine	2053	only	-	May	24	2:00	1:00	S
+Rule Palestine	2054	only	-	Apr	 4	2:00	0	-
+Rule Palestine	2054	only	-	May	16	2:00	1:00	S
+Rule Palestine	2055	only	-	May	 1	2:00	1:00	S
+Rule Palestine	2056	only	-	Apr	22	2:00	1:00	S
+Rule Palestine	2057	only	-	Apr	 7	2:00	1:00	S
+Rule Palestine	2058	max	-	Mar	Sat<=30	2:00	1:00	S
+Rule Palestine	2068	only	-	Oct	20	2:00	0	-
+Rule Palestine	2069	only	-	Oct	12	2:00	0	-
+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	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	-
+Rule Palestine	2077	only	-	Aug	28	2:00	1:00	S
+Rule Palestine	2078	only	-	Jul	 9	2:00	0	-
+Rule Palestine	2078	only	-	Aug	13	2:00	1:00	S
+Rule Palestine	2079	only	-	Jun	24	2:00	0	-
+Rule Palestine	2079	only	-	Aug	 5	2:00	1:00	S
+Rule Palestine	2080	only	-	Jun	15	2:00	0	-
+Rule Palestine	2080	only	-	Jul	20	2:00	1:00	S
+Rule Palestine	2081	only	-	Jun	 7	2:00	0	-
+Rule Palestine	2081	only	-	Jul	12	2:00	1:00	S
+Rule Palestine	2082	only	-	May	23	2:00	0	-
+Rule Palestine	2082	only	-	Jul	 4	2:00	1:00	S
+Rule Palestine	2083	only	-	May	15	2:00	0	-
+Rule Palestine	2083	only	-	Jun	19	2:00	1:00	S
+Rule Palestine	2084	only	-	Apr	29	2:00	0	-
+Rule Palestine	2084	only	-	Jun	10	2:00	1:00	S
+Rule Palestine	2085	only	-	Apr	21	2:00	0	-
+Rule Palestine	2085	only	-	Jun	 2	2:00	1:00	S
+Rule Palestine	2086	only	-	Apr	13	2:00	0	-
+Rule Palestine	2086	only	-	May	18	2:00	1:00	S
 
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
 Zone	Asia/Gaza	2:17:52	-	LMT	1900 Oct
@@ -3632,7 +3742,7 @@ Zone	Asia/Singapore	6:55:25 -	LMT	1901 Jan  1
 # standard time is SLST.
 #
 # From Paul Eggert (2016-10-18):
-# "SLST" seems to be reasonably recent and rarely-used outside time
+# "SLST" seems to be reasonably recent and rarely used outside time
 # zone nerd sources.  I searched Google News and found three uses of
 # it in the International Business Times of India in February and
 # March of this year when discussing cricket match times, but nothing
diff --git a/australasia b/australasia
index af0410ab9035..0633a30efd8b 100644
--- a/australasia
+++ b/australasia
@@ -323,7 +323,7 @@ Zone Antarctica/Macquarie 0	-	-00	1899 Nov
 
 # From Steffen Thorsen (2013-01-10):
 # Fiji will end DST on 2014-01-19 02:00:
-# http://www.fiji.gov.fj/Media-Center/Press-Releases/DAYLIGHT-SAVINGS-TO-END-THIS-MONTH-%281%29.aspx
+# http://www.fiji.gov.fj/Media-Center/Press-Releases/DAYLIGHT-SAVINGS-TO-END-THIS-MONTH-(1).aspx
 
 # From Ken Rylander (2014-10-20):
 # DST will start Nov. 2 this year.
@@ -723,7 +723,7 @@ Zone Pacific/Pago_Pago	 12:37:12 -	LMT	1892 Jul  5
 #
 # Samoa's Daylight Saving Time Act 2009 is available here, but does not
 # contain any dates:
-# http://www.parliament.gov.ws/documents/acts/Daylight%20Saving%20Act%20%202009%20%28English%29%20-%20Final%207-7-091.pdf
+# http://www.parliament.gov.ws/documents/acts/Daylight%20Saving%20Act%20%202009%20(English)%20-%20Final%207-7-091.pdf
 
 # From Laupue Raymond Hughes (2010-10-07):
 # Please see
@@ -1808,7 +1808,7 @@ Zone	Pacific/Efate	11:13:16 -	LMT	1912 Jan 13 # Vila
 # period.  It would probably be reasonable to assume Guam use GMT+9 during
 # that period of time like the surrounding area.
 
-# From Paul Eggert (2018-11-18):
+# From Paul Eggert (2023-01-23):
 # Howse writes (p 153) "The Spaniards, on the other hand, reached the
 # Philippines and the Ladrones from America," and implies that the Ladrones
 # (now called the Marianas) kept American date for quite some time.
@@ -1821,7 +1821,7 @@ Zone	Pacific/Efate	11:13:16 -	LMT	1912 Jan 13 # Vila
 # they did as that avoids the need for a separate zone due to our 1970 cutoff.
 #
 # US Public Law 106-564 (2000-12-23) made UT +10 the official standard time,
-# under the name "Chamorro Standard Time".  There is no official abbreviation,
+# under the name "Chamorro standard time".  There is no official abbreviation,
 # but Congressman Robert A. Underwood, author of the bill that became law,
 # wrote in a press release (2000-12-27) that he will seek the use of "ChST".
 
@@ -2199,24 +2199,18 @@ Zone	Pacific/Efate	11:13:16 -	LMT	1912 Jan 13 # Vila
 # an international standard, there are some places on the high seas where the
 # correct date is ambiguous.
 
-# From Wikipedia <https://en.wikipedia.org/wiki/Time_zone> (2005-08-31):
-# Before 1920, all ships kept local apparent time on the high seas by setting
-# their clocks at night or at the morning sight so that, given the ship's
-# speed and direction, it would be 12 o'clock when the Sun crossed the ship's
-# meridian (12 o'clock = local apparent noon).  During 1917, at the
-# Anglo-French Conference on Time-keeping at Sea, it was recommended that all
-# ships, both military and civilian, should adopt hourly standard time zones
-# on the high seas.  Whenever a ship was within the territorial waters of any
-# nation it would use that nation's standard time.  The captain was permitted
-# to change his ship's clocks at a time of his choice following his ship's
-# entry into another zone time - he often chose midnight.  These zones were
-# adopted by all major fleets between 1920 and 1925 but not by many
-# independent merchant ships until World War II.
-
-# From Paul Eggert, using references suggested by Oscar van Vlijmen
-# (2005-03-20):
-#
-# The American Practical Navigator (2002)
-# http://pollux.nss.nima.mil/pubs/pubs_j_apn_sections.html?rid=187
-# talks only about the 180-degree meridian with respect to ships in
-# international waters; it ignores the international date line.
+# From Wikipedia <https://en.wikipedia.org/wiki/Nautical_time> (2023-01-23):
+# The nautical time zone system is analogous to the terrestrial time zone
+# system for use on high seas.  Under the system time changes are required for
+# changes of longitude in one-hour steps.  The one-hour step corresponds to a
+# time zone width of 15° longitude.  The 15° gore that is offset from GMT or
+# UT1 (not UTC) by twelve hours is bisected by the nautical date line into two
+# 7°30' gores that differ from GMT by ±12 hours.  A nautical date line is
+# implied but not explicitly drawn on time zone maps.  It follows the 180th
+# meridian except where it is interrupted by territorial waters adjacent to
+# land, forming gaps: it is a pole-to-pole dashed line.
+
+# From Paul Eggert (2023-01-23):
+# The American Practical Navigator <https://msi.nga.mil/Publications/APN>,
+# 2019 edition, merely says that the International Date Line
+# "coincides with the 180th meridian over most of its length."
diff --git a/backward b/backward
index 0ae5d74108e6..421f2ec6b9f8 100644
--- a/backward
+++ b/backward
@@ -274,6 +274,7 @@ Link	America/Argentina/Cordoba	America/Rosario
 Link	America/Tijuana		America/Santa_Isabel
 Link	America/Denver		America/Shiprock
 Link	America/Toronto		America/Thunder_Bay
+Link	America/Edmonton	America/Yellowknife
 Link	Pacific/Auckland	Antarctica/South_Pole
 Link	Asia/Shanghai		Asia/Chongqing
 Link	Asia/Shanghai		Asia/Harbin
diff --git a/backzone b/backzone
index 7803c57d095d..44d81c29e5ae 100644
--- a/backzone
+++ b/backzone
@@ -169,7 +169,7 @@ Zone	Africa/Accra	-0:00:52 -	LMT	1915 Nov  2
 # 12-hour clock starting at our 06:00, so their "8 o'clock" is our
 # 02:00 or 14:00.  Keep this in mind when you ask the time in Amharic.
 #
-# Shanks & Pottenger write that Ethiopia had six narrowly-spaced time
+# Shanks & Pottenger write that Ethiopia had six narrowly spaced time
 # zones between 1870 and 1890, that they merged to 38E50 (2:35:20) in
 # 1890, and that they switched to 3:00 on 1936-05-05.  Perhaps 38E50
 # was for Adis Dera.  Quite likely the Shanks data entries are wrong
@@ -499,7 +499,7 @@ Zone	America/Aruba	-4:40:24 -	LMT	1912 Feb 12 # Oranjestad
 # ever since standard time was introduced, but the information from
 # McKinnon sounds more authoritative.  For now, assume that Atikokan
 # switched to EST immediately after WWII era daylight saving time
-# ended.  This matches the old (less-populous) America/Coral_Harbour
+# ended.  This matches the old (less populous) America/Coral_Harbour
 # entry since our cutoff date of 1970, so we can move
 # America/Coral_Harbour to the 'backward' file.
 
@@ -928,6 +928,11 @@ Zone America/Thunder_Bay -5:57:00 -	LMT	1895
 Zone America/Tortola	-4:18:28 -	LMT	1911 Jul # Road Town
 			-4:00	-	AST
 
+# Yellowknife, Northwest Territories
+Zone America/Yellowknife 0	-	-00	1935 # Yellowknife founded?
+			-7:00	NT_YK	M%sT	1980
+			-7:00	Canada	M%sT
+
 # Dumont d'Urville, Île des Pétrels, -6640+14001, since 1956-11
 # <https://en.wikipedia.org/wiki/Dumont_d'Urville_Station> (2005-12-05)
 #
@@ -1756,7 +1761,7 @@ Link Pacific/Chuuk Pacific/Yap
 # Enderbury was inhabited 1860/1880s to mine guano, and 1938-03-06/1942-02-09
 # for aviation (ostensibly commercial, but military uses foreseen).
 # The 19th-century dates are approximate.  See Pacific/Kanton for
-# the currently-inhabited representative for this timezone.
+# the currently inhabited representative for this timezone.
 Zone Pacific/Enderbury	0	-	-00	1860
 			-11:24:20 -	LMT	1885
 			0	-	-00	1938 Mar  6
diff --git a/checktab.awk b/checktab.awk
index 23e0a3a5c567..2dbf485fda3a 100644
--- a/checktab.awk
+++ b/checktab.awk
@@ -107,6 +107,7 @@ BEGIN {
 	    cc = cca[j]
 	    if (used_max < cc_used[cc]) {
 	      used_max = cc_used[cc]
+	      used_max_cc = cc
 	    }
 	  }
 	  if (used_max <= 1 && comments) {
@@ -114,9 +115,9 @@ BEGIN {
 	      zone_table, i, comments \
 	      >>"/dev/stderr"
 	    status = 1
-	  } else if (1 < cc_used[cc] && !comments) {
+	  } else if (1 < used_max && !comments) {
 	    printf "%s:%d: missing comment for %s\n", \
-	      zone_table, i, cc \
+	      zone_table, i, used_max_cc \
 	      >>"/dev/stderr"
 	    status = 1
 	  }
diff --git a/europe b/europe
index a3547b4f81a4..3907c055140a 100644
--- a/europe
+++ b/europe
@@ -517,9 +517,7 @@ Zone	Europe/London	-0:01:15 -	LMT	1847 Dec  1
 # other form with a traditional approximation for Irish timestamps
 # after 1971-10-31 02:00 UTC; although this approximation has tm_isdst
 # flags that are reversed, its UTC offsets are correct and this often
-# suffices.  This source file currently uses only nonnegative SAVE
-# values, but this is intended to change and downstream code should
-# not rely on it.
+# suffices....
 #
 # The following is like GB-Eire and EU, except with standard time in
 # summer and negative daylight saving time in winter.  It is for when
@@ -1113,19 +1111,18 @@ Zone Atlantic/Faroe	-0:27:04 -	LMT	1908 Jan 11 # Tórshavn
 #
 # From Jürgen Appel (2022-11-25):
 # https://ina.gl/samlinger/oversigt-over-samlinger/samling/dagsordener/dagsorden.aspx?lang=da&day=24-11-2022
-# If I understand this correctly, from the next planned switch to
-# summer time, Greenland will permanently stay at that time, i.e. no
-# switch back to winter time in 2023 will occur.
-#
-# From Paul Eggert (2022-11-28):
-# The official document in Danish
-# https://naalakkersuisut.gl/-/media/naalakkersuisut/filer/kundgoerelser/2022/11/2511/31_da_inatsisartutlov-om-tidens-bestemmelse.pdf?la=da&hash=A33597D8A38CC7038465241119EF34F3
-# says standard time for Greenland is -02, that Naalakkersuisut can lay down
-# rules for DST and can require some areas to use a different time zone,
-# and that this all takes effect 2023-03-25 22:00.  The abovementioned
-# "bekymringer" URL says the intent is no transition March 25, that
-# Greenland will not go back to winter time in fall 2023, and that
-# only America/Nuuk is affected (though further changes may occur).
+#
+# From Thomas M. Steenholdt (2022-12-02):
+# - The bill to move America/Nuuk from UTC-03 to UTC-02 passed.
+# - The bill to stop observing DST did not (Greenland will stop observing DST
+#   when EU does).
+# Details on the implementation are here (section 6):
+# https://ina.gl/dvd/EM%202022/pdf/media/2553529/pkt17_em2022_tidens_bestemmelse_bem_da.pdf
+# This is how the change will be implemented:
+# 1. The shift *to* DST in 2023 happens as normal.
+# 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.
 
 # Rule	NAME	FROM	TO	-	IN	ON	AT	SAVE	LETTER/S
 Rule	Thule	1991	1992	-	Mar	lastSun	2:00	1:00	D
@@ -1149,8 +1146,8 @@ Zone America/Scoresbysund -1:27:52 -	LMT	1916 Jul 28 # Ittoqqortoormiit
 			-1:00	EU	-01/+00
 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 Mar 25 22:00
-			-2:00	-	-02
+			-3:00	EU	-03/-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
 
@@ -1486,9 +1483,9 @@ Zone	Europe/Paris	0:09:21 -	LMT	1891 Mar 16
 Rule	Germany	1946	only	-	Apr	14	2:00s	1:00	S
 Rule	Germany	1946	only	-	Oct	 7	2:00s	0	-
 Rule	Germany	1947	1949	-	Oct	Sun>=1	2:00s	0	-
-# http://www.ptb.de/de/org/4/44/441/salt.htm says the following transition
-# occurred at 3:00 MEZ, not the 2:00 MEZ given in Shanks & Pottenger.
-# Go with the PTB.
+# https://www.ptb.de/cms/en/ptb/fachabteilungen/abt4/fb-44/ag-441/realisation-of-legal-time-in-germany/dst-and-midsummer-dst-in-germany-until-1979.html
+# says the following transition occurred at 3:00 MEZ, not the 2:00 MEZ
+# given in Shanks & Pottenger. Go with the PTB.
 Rule	Germany	1947	only	-	Apr	 6	3:00s	1:00	S
 Rule	Germany	1947	only	-	May	11	2:00s	2:00	M
 Rule	Germany	1947	only	-	Jun	29	3:00	1:00	S
@@ -2249,7 +2246,7 @@ Zone Europe/Bucharest	1:44:24 -	LMT	1891 Oct
 # the State Duma has approved ... the draft bill on returning to
 # winter time standard and return Russia 11 time zones.  The new
 # regulations will come into effect on October 26, 2014 at 02:00 ...
-# http://asozd2.duma.gov.ru/main.nsf/%28Spravka%29?OpenAgent&RN=431985-6&02
+# http://asozd2.duma.gov.ru/main.nsf/(Spravka)?OpenAgent&RN=431985-6&02
 # Here is a link where we put together table (based on approved Bill N
 # 431985-6) with proposed 11 Russian time zones and corresponding
 # areas/cities/administrative centers in the Russian Federation (in English):
@@ -2659,13 +2656,13 @@ Zone Europe/Volgograd	 2:57:40 -	LMT	1920 Jan  3
 			 3:00	-	+03	1930 Jun 21
 			 4:00	-	+04	1961 Nov 11
 			 4:00	Russia	+04/+05	1988 Mar 27  2:00s
-			 3:00	Russia	+03/+04	1991 Mar 31  2:00s
+			 3:00	Russia	MSK/MSD	1991 Mar 31  2:00s
 			 4:00	-	+04	1992 Mar 29  2:00s
-			 3:00	Russia	+03/+04	2011 Mar 27  2:00s
-			 4:00	-	+04	2014 Oct 26  2:00s
-			 3:00	-	+03	2018 Oct 28  2:00s
+			 3:00	Russia	MSK/MSD	2011 Mar 27  2:00s
+			 4:00	-	MSK	2014 Oct 26  2:00s
+			 3:00	-	MSK	2018 Oct 28  2:00s
 			 4:00	-	+04	2020 Dec 27  2:00s
-			 3:00	-	+03
+			 3:00	-	MSK
 
 # From Paul Eggert (2016-11-11):
 # Europe/Saratov covers:
@@ -2696,11 +2693,11 @@ Zone Europe/Saratov	 3:04:18 -	LMT	1919 Jul  1  0:00u
 Zone Europe/Kirov	 3:18:48 -	LMT	1919 Jul  1  0:00u
 			 3:00	-	+03	1930 Jun 21
 			 4:00	Russia	+04/+05	1989 Mar 26  2:00s
-			 3:00	Russia	+03/+04	1991 Mar 31  2:00s
+			 3:00	Russia	MSK/MSD	1991 Mar 31  2:00s
 			 4:00	-	+04	1992 Mar 29  2:00s
-			 3:00	Russia	+03/+04	2011 Mar 27  2:00s
-			 4:00	-	+04	2014 Oct 26  2:00s
-			 3:00	-	+03
+			 3:00	Russia	MSK/MSD	2011 Mar 27  2:00s
+			 4:00	-	MSK	2014 Oct 26  2:00s
+			 3:00	-	MSK
 
 # From Tim Parenti (2014-07-03), per Oscar van Vlijmen (2001-08-25):
 # Europe/Samara covers...
diff --git a/iso3166.tab b/iso3166.tab
index 911af5e837e2..be3348d11a79 100644
--- a/iso3166.tab
+++ b/iso3166.tab
@@ -238,7 +238,7 @@ SY	Syria
 SZ	Eswatini (Swaziland)
 TC	Turks & Caicos Is
 TD	Chad
-TF	French Southern Territories
+TF	French S. Terr.
 TG	Togo
 TH	Thailand
 TJ	Tajikistan
diff --git a/leap-seconds.list b/leap-seconds.list
index 5b519b703e0e..17e3a100f943 100644
--- a/leap-seconds.list
+++ b/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 C64
-#	File expires on:  28 June 2023
+#	Updated through IERS Bulletin C65
+#	File expires on:  28 December 2023
 #
-#@	3896899200
+#@	3912710400
 #
 2272060800	10	# 1 Jan 1972
 2287785600	11	# 1 Jul 1972
@@ -252,4 +252,4 @@
 #	the hash line is also ignored in the
 #	computation.
 #
-#h 	2c413af9 124e1031 f165174 ff527c6b 756ae00b
+#h 	e76a99dc 65f15cc7 e613e040 f5078b5e b23834fe
diff --git a/leapseconds b/leapseconds
index 6826ac4a32f5..a6a170aa7028 100644
--- a/leapseconds
+++ b/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	Jun	28	00:00:00
+#Expires 2023	Dec	28	00:00:00
 
 # POSIX timestamps for the data in this file:
 #updated 1467936000 (2016-07-08 00:00:00 UTC)
-#expires 1687910400 (2023-06-28 00:00:00 UTC)
+#expires 1703721600 (2023-12-28 00:00:00 UTC)
 
-#	Updated through IERS Bulletin C64
-#	File expires on:  28 June 2023
+#	Updated through IERS Bulletin C65
+#	File expires on:  28 December 2023
diff --git a/leapseconds.awk b/leapseconds.awk
index b6c48bcce0cd..7d2556bf1ca7 100644
--- a/leapseconds.awk
+++ b/leapseconds.awk
@@ -104,18 +104,23 @@ BEGIN {
 }
 
 END {
-    sstamp_to_ymdhMs(expires, ss_NTP)
-
     print ""
-    print "# UTC timestamp when this leap second list expires."
-    print "# Any additional leap seconds will come after this."
-    if (! EXPIRES_LINE) {
-      print "# This Expires line is commented out for now,"
-      print "# so that pre-2020a zic implementations do not reject this file."
+
+    if (expires) {
+      sstamp_to_ymdhMs(expires, ss_NTP)
+
+      print "# UTC timestamp when this leap second list expires."
+      print "# Any additional leap seconds will come after this."
+      if (! EXPIRES_LINE) {
+	print "# This Expires line is commented out for now,"
+	print "# so that pre-2020a zic implementations do not reject this file."
+      }
+      printf "%sExpires %.4d\t%s\t%.2d\t%.2d:%.2d:%.2d\n", \
+	EXPIRES_LINE ? "" : "#", \
+	ss_year, monthabbr[ss_month], ss_mday, ss_hour, ss_min, ss_sec
+    } else {
+      print "# (No Expires line, since the expires time is unknown.)"
     }
-    printf "%sExpires %.4d\t%s\t%.2d\t%.2d:%.2d:%.2d\n", \
-      EXPIRES_LINE ? "" : "#", \
-      ss_year, monthabbr[ss_month], ss_mday, ss_hour, ss_min, ss_sec
 
     # The difference between the NTP and POSIX epochs is 70 years
     # (including 17 leap days), each 24 hours of 60 minutes of 60
@@ -124,15 +129,22 @@ END {
 
     print ""
     print "# POSIX timestamps for the data in this file:"
-    sstamp_to_ymdhMs(updated, ss_NTP)
-    printf "#updated %d (%.4d-%.2d-%.2d %.2d:%.2d:%.2d UTC)\n", \
-      updated - epoch_minus_NTP, \
-      ss_year, ss_month, ss_mday, ss_hour, ss_min, ss_sec
-    sstamp_to_ymdhMs(expires, ss_NTP)
-    printf "#expires %d (%.4d-%.2d-%.2d %.2d:%.2d:%.2d UTC)\n", \
-      expires - epoch_minus_NTP, \
-      ss_year, ss_month, ss_mday, ss_hour, ss_min, ss_sec
-
+    if (updated) {
+      sstamp_to_ymdhMs(updated, ss_NTP)
+      printf "#updated %d (%.4d-%.2d-%.2d %.2d:%.2d:%.2d UTC)\n", \
+	updated - epoch_minus_NTP, \
+	ss_year, ss_month, ss_mday, ss_hour, ss_min, ss_sec
+    } else {
+      print "#(updated time unknown)"
+    }
+    if (expires) {
+      sstamp_to_ymdhMs(expires, ss_NTP)
+      printf "#expires %d (%.4d-%.2d-%.2d %.2d:%.2d:%.2d UTC)\n", \
+	expires - epoch_minus_NTP, \
+	ss_year, ss_month, ss_mday, ss_hour, ss_min, ss_sec
+    } else {
+      print "#(expires time unknown)"
+    }
     printf "\n%s", last_lines
 }
 
diff --git a/northamerica b/northamerica
index d50581d00774..d8e3601ca219 100644
--- a/northamerica
+++ b/northamerica
@@ -276,9 +276,10 @@ Zone	PST8PDT		 -8:00	US	P%sT
 #  -10	Standard Alaska Time (AST)	Alaska-Hawaii standard time (AHST)
 #  -11	(unofficial) Nome (NST)		Bering standard time (BST)
 #
-# From Paul Eggert (2000-01-08), following a heads-up from Rives McDow:
-# Public law 106-564 (2000-12-23) introduced ... "Chamorro Standard Time"
+# From Paul Eggert (2023-01-23), from a 2001-01-08 heads-up from Rives McDow:
+# Public law 106-564 (2000-12-23) introduced "Chamorro standard time"
 # for time in Guam and the Northern Marianas.  See the file "australasia".
+# Also see 15 U.S.C. §263 <https://www.law.cornell.edu/uscode/text/15/263>.
 #
 # From Paul Eggert (2015-04-17):
 # HST and HDT are standardized abbreviations for Hawaii-Aleutian
@@ -595,7 +596,7 @@ Zone America/Los_Angeles -7:52:58 -	LMT	1883 Nov 18 20:00u
 # local times of other Alaskan locations so that they change simultaneously.
 
 # From Paul Eggert (2014-07-18):
-# One opinion of the early-1980s turmoil in Alaska over time zones and
+# One opinion of the early 1980s turmoil in Alaska over time zones and
 # daylight saving time appeared as graffiti on a Juneau airport wall:
 # "Welcome to Juneau.  Please turn your watch back to the 19th century."
 # See: Turner W. Alaska's four time zones now two. NY Times 1983-11-01.
@@ -667,6 +668,10 @@ Zone America/Los_Angeles -7:52:58 -	LMT	1883 Nov 18 20:00u
 # So they won't be waiting for Alaska to join them on 2019-03-10, but will
 # rather change their clocks twice in seven weeks.
 
+# From Paul Eggert (2023-01-23):
+# America/Adak is for the Aleutian Islands that are part of Alaska
+# and are west of 169.5° W.
+
 # Zone	NAME		STDOFF	RULES	FORMAT	[UNTIL]
 Zone America/Juneau	 15:02:19 -	LMT	1867 Oct 19 15:33:32
 			 -8:57:41 -	LMT	1900 Aug 20 12:00
@@ -2125,10 +2130,6 @@ Zone America/Fort_Nelson	-8:10:47 -	LMT	1884
 # Nunavut ... moved ... to incorporate the whole territory into one time zone.
 # Nunavut moves to single time zone Oct. 31
 # http://www.nunatsiaq.com/nunavut/nvt90903_13.html
-#
-# From Antoine Leca (1999-09-06):
-# We then need to create a new timezone for the Kitikmeot region of Nunavut
-# to differentiate it from the Yellowknife region.
 
 # From Paul Eggert (1999-09-20):
 # Basic Facts: The New Territory
@@ -2322,9 +2323,6 @@ Zone America/Cambridge_Bay 0	-	-00	1920 # trading post est.?
 			-5:00	-	EST	2000 Nov  5  0:00
 			-6:00	-	CST	2001 Apr  1  3:00
 			-7:00	Canada	M%sT
-Zone America/Yellowknife 0	-	-00	1935 # Yellowknife founded?
-			-7:00	NT_YK	M%sT	1980
-			-7:00	Canada	M%sT
 Zone America/Inuvik	0	-	-00	1953 # Inuvik founded
 			-8:00	NT_YK	P%sT	1979 Apr lastSun  2:00
 			-7:00	NT_YK	M%sT	1980
@@ -2561,7 +2559,7 @@ Zone America/Dawson	-9:17:40 -	LMT	1900 Aug 20
 # and in addition changes all of Chihuahua to -06 with no DST.
 
 # From Heitor David Pinto (2022-11-28):
-# Now the northern municipalities want to have the same time zone as the
+# Now the northern [municipios] want to have the same time zone as the
 # respective neighboring cities in the US, for example Juárez in UTC-7 with
 # DST, matching El Paso, and Ojinaga in UTC-6 with DST, matching Presidio....
 # the president authorized the publication of the decree for November 29,
@@ -2598,7 +2596,7 @@ Zone America/Merida	-5:58:28 -	LMT	1922 Jan  1  6:00u
 			-5:00	-	EST	1982 Dec  2
 			-6:00	Mexico	C%sT
 # Coahuila, Nuevo León, Tamaulipas (near US border)
-# This includes the following municipalities:
+# This includes the following municipios:
 #   in Coahuila: Acuña, Allende, Guerrero, Hidalgo, Jiménez, Morelos, Nava,
 #     Ocampo, Piedras Negras, Villa Unión, Zaragoza
 #   in Nuevo León: Anáhuac
@@ -2624,8 +2622,8 @@ Zone America/Mexico_City -6:36:36 -	LMT	1922 Jan  1  7:00u
 			-6:00	-	CST	2002 Feb 20
 			-6:00	Mexico	C%sT
 # Chihuahua (near US border - western side)
-# This includes the municipalities of Janos, Ascensión, Juárez, Guadalupe,
-# and Práxedis G Guerrero.
+# This includes the municipios of Janos, Ascensión, Juárez, Guadalupe, and
+# Práxedis G Guerrero.
 # http://gaceta.diputados.gob.mx/PDF/65/2a022/nov/20221124-VII.pdf
 Zone America/Ciudad_Juarez -7:05:56 -	LMT	1922 Jan  1  7:00u
 			-7:00	-	MST	1927 Jun 10 23:00
@@ -2639,7 +2637,8 @@ Zone America/Ciudad_Juarez -7:05:56 -	LMT	1922 Jan  1  7:00u
 			-6:00	-	CST	2022 Nov 30  0:00
 			-7:00	US	M%sT
 # Chihuahua (near US border - eastern side)
-# The municipalities of Coyame del Sotol, Ojinaga, and Manuel Benavides.
+# This includes the municipios of Coyame del Sotol, Ojinaga, and Manuel
+# Benavides.
 # http://gaceta.diputados.gob.mx/PDF/65/2a022/nov/20221124-VII.pdf
 Zone America/Ojinaga	-6:57:40 -	LMT	1922 Jan  1  7:00u
 			-7:00	-	MST	1927 Jun 10 23:00
@@ -3060,7 +3059,7 @@ Zone America/Costa_Rica	-5:36:13 -	LMT	1890        # San José
 #
 # He supplied these references:
 #
-# http://www.prensalatina.com.mx/article.asp?ID=%7B4CC32C1B-A9F7-42FB-8A07-8631AFC923AF%7D&language=ES
+# http://www.prensalatina.com.mx/article.asp?ID={4CC32C1B-A9F7-42FB-8A07-8631AFC923AF}&language=ES
 # http://actualidad.terra.es/sociedad/articulo/cuba_llama_ahorrar_energia_cambio_1957044.htm
 #
 # From Alex Krivenyshev (2007-10-25):
diff --git a/southamerica b/southamerica
index 87b71d5f9210..e55c5f0842c0 100644
--- a/southamerica
+++ b/southamerica
@@ -208,7 +208,7 @@ Rule	Arg	2008	only	-	Oct	Sun>=15	0:00	1:00	-
 # Hora de verano para la República Argentina
 # http://buenasiembra.com.ar/esoterismo/astrologia/hora-de-verano-de-la-republica-argentina-27.html
 # says that standard time in Argentina from 1894-10-31
-# to 1920-05-01 was -4:16:48.25.  Go with this more-precise value
+# to 1920-05-01 was -4:16:48.25.  Go with this more precise value
 # over Shanks & Pottenger.  It is upward compatible with Milne, who
 # says Córdoba time was -4:16:48.2.
 
diff --git a/theory.html b/theory.html
index 75e347f0f9d1..369c75433ff2 100644
--- a/theory.html
+++ b/theory.html
@@ -23,7 +23,7 @@
       <li><a href="#stability">Interface stability</a></li>
       <li><a href="#leapsec">Leap seconds</a></li>
       <li><a href="#calendar">Calendrical issues</a></li>
-      <li><a href="#planets">Time and time zones on other planets</a></li>
+      <li><a href="#planets">Time and time zones off earth</a></li>
     </ul>
   </nav>
 
@@ -443,11 +443,11 @@ in decreasing order of importance:
       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,
@@ -460,13 +460,13 @@ in decreasing order of importance:
       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&ndash;present,
       PKT/PKST Pakistan,
-      PST/PDT/PWT/PPT/PDDT Pacific,
+      PST/PDT/PWT/PPT Pacific,
       PST/PDT Philippine,
       SAST South Africa,
       SST Samoa,
@@ -494,7 +494,7 @@ in decreasing order of importance:
     <p>
     <small>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;
@@ -506,12 +506,13 @@ in decreasing order of importance:
       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;
@@ -519,8 +520,7 @@ in decreasing order of importance:
       SMT Santiago, Simferopol, Singapore, Stanley;
       TBMT Tbilisi;
       TMT Tallinn, Tehran;
-      WMT Warsaw;
-      ZMT Zomba.</small>
+      WMT Warsaw.</small>
     </p>
 
     <p>
@@ -791,7 +791,7 @@ href="https://www.dissentmagazine.org/blog/booked-a-global-history-of-time-vanes
     with days starting at midnight.
     Although <abbr>UT</abbr> equals <abbr>UTC</abbr> for modern
     timestamps, <abbr>UTC</abbr> was not defined until 1960, so
-    commentary uses the more-general abbreviation <abbr>UT</abbr> for
+    commentary uses the more general abbreviation <abbr>UT</abbr> for
     timestamps that might predate 1960.
     Since <abbr>UT</abbr>, <abbr>UT1</abbr>, etc. disagree slightly,
     and since pre-1972 <abbr>UTC</abbr> seconds varied in length,
@@ -818,7 +818,8 @@ href="https://www.dissentmagazine.org/blog/booked-a-global-history-of-time-vanes
   <li>
     The relationship between POSIX time (that is, <abbr>UTC</abbr> but
     ignoring <a href="https://en.wikipedia.org/wiki/Leap_second">leap
-    seconds</a>) and <abbr>UTC</abbr> is not agreed upon after 1972.
+    seconds</a>) and <abbr>UTC</abbr> is not agreed upon.
+    This affects time stamps during the leap second era (1972&ndash;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
@@ -877,7 +878,7 @@ an older <code>zic</code>.
     is error-prone in practice.
     Also, POSIX <code>TZ</code> 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 <abbr>UT</abbr> offsets are used in an area.
     </p>
 
@@ -913,8 +914,8 @@ an older <code>zic</code>.
       <dt><var>date</var>[<code>/</code><var>time</var>]<code>,</code><var>date</var>[<code>/</code><var>time</var>]</dt><dd>
 	specifies the beginning and end of <abbr>DST</abbr>.
 	If this is absent, the system supplies its own ruleset
-	for <abbr>DST</abbr>, and its rules can differ from year to year;
-	typically <abbr>US</abbr> <abbr>DST</abbr> rules are used.
+	for <abbr>DST</abbr>, typically	current <abbr>US</abbr>
+	<abbr>DST</abbr> rules.
       </dd>
       <dt><var>time</var></dt><dd>
 	takes the form
@@ -974,10 +975,11 @@ an older <code>zic</code>.
     Traditionally the current <abbr>US</abbr> <abbr>DST</abbr> rules
     were used to interpret such values, but this meant that the
     <abbr>US</abbr> <abbr>DST</abbr> rules were compiled into each
-    program that did time conversion. This meant that when
+    time conversion package, and when
     <abbr>US</abbr> 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 <code>TZ</code> values had to be updated
+    to ensure proper results.
   </li>
   <li>
     The <code>TZ</code> environment variable is process-global, which
@@ -1173,7 +1175,7 @@ The vestigial <abbr>API</abbr>s are:
   </li>
   <li>
     The functions that are conditionally compiled
-    if <code>STD_INSPIRED</code> is defined should, at this point, be
+    if <code>STD_INSPIRED</code> is nonzero should, at this point, be
     looked on primarily as food for thought.
     They are not in any sense "standard compatible" &ndash; some are
     not, in fact, specified in <em>any</em> standard.
@@ -1240,7 +1242,7 @@ The <code><abbr>tz</abbr></code> code and data supply the following interfaces:
 Interface changes in a release attempt to preserve compatibility with
 recent releases.
 For example, <code><abbr>tz</abbr></code> data files typically do not
-rely on recently-added <code>zic</code> features, so that users can
+rely on recently added <code>zic</code> features, so that users can
 run older <code>zic</code> versions to process newer data files.
 <a href="tz-link.html#download">Downloading
 the <code><abbr>tz</abbr></code> database</a> describes how releases
@@ -1269,6 +1271,18 @@ between now and the future time.
 <section>
   <h2 id="leapsec">Leap seconds</h2>
 <p>
+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 <a href="https://www.bipm.org/en/cgpm-2022/resolution-4">planned
+to be discontinued by 2035</a>, 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.
+</p>
+
+<p>
 The <code><abbr>tz</abbr></code> 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
@@ -1282,12 +1296,12 @@ commonly used by
 <a href="https://www.ntp.org"><abbr title="Network Time Protocol">NTP</abbr></a>
 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.
 </p>
 
 <p>
-The directly-supported mechanism assumes that <code>time_t</code>
+The directly supported mechanism assumes that <code>time_t</code>
 counts of seconds since the POSIX epoch normally include leap seconds,
 as opposed to POSIX <code>time_t</code> counts which exclude leap seconds.
 This modified timescale is converted to <abbr>UTC</abbr>
@@ -1348,7 +1362,15 @@ They sometimes disagree.
 </section>
 
 <section>
-  <h2 id="planets">Time and time zones on other planets</h2>
+  <h2 id="planets">Time and time zones off Earth</h2>
+<p>
+The European Space Agency is <a
+href='https://www.esa.int/Applications/Navigation/Telling_time_on_the_Moon'>considering</a>
+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.
+</p>
+
 <p>
 Some people's work schedules have used
 <a href="https://en.wikipedia.org/wiki/Timekeeping_on_Mars">Mars time</a>.
diff --git a/version b/version
index b74fa117a223..41e28b248330 100644
--- a/version
+++ b/version
@@ -1 +1 @@
-2022g
+2023a
diff --git a/zone.tab b/zone.tab
index 6e5adb9fcca6..dbcb61793eeb 100644
--- a/zone.tab
+++ b/zone.tab
@@ -121,9 +121,8 @@ 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); 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	+6227-11421	America/Yellowknife	Mountain - NT (central)
 CA	+682059-1334300	America/Inuvik	Mountain - NT (west)
 CA	+4906-11631	America/Creston	MST - BC (Creston)
 CA	+5546-12014	America/Dawson_Creek	MST - BC (Dawson Cr, Ft St John)
@@ -139,7 +138,7 @@ CG	-0416+01517	Africa/Brazzaville
 CH	+4723+00832	Europe/Zurich
 CI	+0519-00402	Africa/Abidjan
 CK	-2114-15946	Pacific/Rarotonga
-CL	-3327-07040	America/Santiago	Chile (most areas)
+CL	-3327-07040	America/Santiago	most of Chile
 CL	-5309-07055	America/Punta_Arenas	Region of Magallanes
 CL	-2709-10926	Pacific/Easter	Easter Island
 CM	+0403+00942	Africa/Douala
@@ -151,10 +150,10 @@ CU	+2308-08222	America/Havana
 CV	+1455-02331	Atlantic/Cape_Verde
 CW	+1211-06900	America/Curacao
 CX	-1025+10543	Indian/Christmas
-CY	+3510+03322	Asia/Nicosia	Cyprus (most areas)
+CY	+3510+03322	Asia/Nicosia	most of Cyprus
 CY	+3507+03357	Asia/Famagusta	Northern Cyprus
 CZ	+5005+01426	Europe/Prague
-DE	+5230+01322	Europe/Berlin	Germany (most areas)
+DE	+5230+01322	Europe/Berlin	most of Germany
 DE	+4742+00841	Europe/Busingen	Busingen
 DJ	+1136+04309	Africa/Djibouti
 DK	+5540+01235	Europe/Copenhagen
@@ -187,7 +186,7 @@ GF	+0456-05220	America/Cayenne
 GG	+492717-0023210	Europe/Guernsey
 GH	+0533-00013	Africa/Accra
 GI	+3608-00521	Europe/Gibraltar
-GL	+6411-05144	America/Nuuk	Greenland (most areas)
+GL	+6411-05144	America/Nuuk	most of Greenland
 GL	+7646-01840	America/Danmarkshavn	National Park (east coast)
 GL	+7029-02158	America/Scoresbysund	Scoresbysund/Ittoqqortoormiit
 GL	+7634-06847	America/Thule	Thule/Pituffik
@@ -235,7 +234,7 @@ KP	+3901+12545	Asia/Pyongyang
 KR	+3733+12658	Asia/Seoul
 KW	+2920+04759	Asia/Kuwait
 KY	+1918-08123	America/Cayman
-KZ	+4315+07657	Asia/Almaty	Kazakhstan (most areas)
+KZ	+4315+07657	Asia/Almaty	most of Kazakhstan
 KZ	+4448+06528	Asia/Qyzylorda	Qyzylorda/Kyzylorda/Kzyl-Orda
 KZ	+5312+06337	Asia/Qostanay	Qostanay/Kostanay/Kustanay
 KZ	+5017+05710	Asia/Aqtobe	Aqtobe/Aktobe
@@ -259,12 +258,12 @@ MD	+4700+02850	Europe/Chisinau
 ME	+4226+01916	Europe/Podgorica
 MF	+1804-06305	America/Marigot
 MG	-1855+04731	Indian/Antananarivo
-MH	+0709+17112	Pacific/Majuro	Marshall Islands (most areas)
+MH	+0709+17112	Pacific/Majuro	most of Marshall Islands
 MH	+0905+16720	Pacific/Kwajalein	Kwajalein
 MK	+4159+02126	Europe/Skopje
 ML	+1239-00800	Africa/Bamako
 MM	+1647+09610	Asia/Yangon
-MN	+4755+10653	Asia/Ulaanbaatar	Mongolia (most areas)
+MN	+4755+10653	Asia/Ulaanbaatar	most of Mongolia
 MN	+4801+09139	Asia/Hovd	Bayan-Olgiy, Govi-Altai, Hovd, Uvs, Zavkhan
 MN	+4804+11430	Asia/Choibalsan	Dornod, Sukhbaatar
 MO	+221150+1133230	Asia/Macau
@@ -302,7 +301,7 @@ NO	+5955+01045	Europe/Oslo
 NP	+2743+08519	Asia/Kathmandu
 NR	-0031+16655	Pacific/Nauru
 NU	-1901-16955	Pacific/Niue
-NZ	-3652+17446	Pacific/Auckland	New Zealand (most areas)
+NZ	-3652+17446	Pacific/Auckland	most of New Zealand
 NZ	-4357-17633	Pacific/Chatham	Chatham Islands
 OM	+2336+05835	Asia/Muscat
 PA	+0858-07932	America/Panama
@@ -310,7 +309,7 @@ PE	-1203-07703	America/Lima
 PF	-1732-14934	Pacific/Tahiti	Society Islands
 PF	-0900-13930	Pacific/Marquesas	Marquesas Islands
 PF	-2308-13457	Pacific/Gambier	Gambier Islands
-PG	-0930+14710	Pacific/Port_Moresby	Papua New Guinea (most areas)
+PG	-0930+14710	Pacific/Port_Moresby	most of Papua New Guinea
 PG	-0613+15534	Pacific/Bougainville	Bougainville
 PH	+1435+12100	Asia/Manila
 PK	+2452+06703	Asia/Karachi
@@ -356,7 +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); North 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
@@ -397,7 +396,7 @@ TT	+1039-06131	America/Port_of_Spain
 TV	-0831+17913	Pacific/Funafuti
 TW	+2503+12130	Asia/Taipei
 TZ	-0648+03917	Africa/Dar_es_Salaam
-UA	+5026+03031	Europe/Kyiv	Ukraine (most areas)
+UA	+5026+03031	Europe/Kyiv	most of Ukraine
 UG	+0019+03225	Africa/Kampala
 UM	+2813-17722	Pacific/Midway	Midway Islands
 UM	+1917+16637	Pacific/Wake	Wake Island
@@ -420,7 +419,7 @@ 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	+332654-1120424	America/Phoenix	MST - Arizona (except Navajo)
+US	+332654-1120424	America/Phoenix	MST - AZ (except Navajo)
 US	+340308-1181434	America/Los_Angeles	Pacific
 US	+611305-1495401	America/Anchorage	Alaska (most areas)
 US	+581807-1342511	America/Juneau	Alaska - Juneau area
@@ -428,7 +427,7 @@ US	+571035-1351807	America/Sitka	Alaska - Sitka area
 US	+550737-1313435	America/Metlakatla	Alaska - Annette Island
 US	+593249-1394338	America/Yakutat	Alaska - Yakutat
 US	+643004-1652423	America/Nome	Alaska (west)
-US	+515248-1763929	America/Adak	Aleutian Islands
+US	+515248-1763929	America/Adak	Alaska - western Aleutians
 US	+211825-1575130	Pacific/Honolulu	Hawaii
 UY	-345433-0561245	America/Montevideo
 UZ	+3940+06648	Asia/Samarkand	Uzbekistan (west)
diff --git a/zone1970.tab b/zone1970.tab
index a9b36d36a56a..1f1cecb84856 100644
--- a/zone1970.tab
+++ b/zone1970.tab
@@ -18,7 +18,10 @@
 #     Please see the theory.html file for how these names are chosen.
 #     If multiple timezones overlap a country, each has a row in the
 #     table, with each column 1 containing the country code.
-# 4.  Comments; present if and only if a country has multiple timezones.
+# 4.  Comments; present if and only if countries have multiple timezones,
+#     and useful only for those countries.  For example, the comments
+#     for the row with countries CH,DE,LI and name Europe/Zurich
+#     are useful only for DE, since CH and LI have no other timezones.
 #
 # If a timezone covers multiple countries, the most-populous city is used,
 # and that country is listed first in column 1; any other countries
@@ -34,7 +37,7 @@
 #country-
 #codes	coordinates	TZ	comments
 AD	+4230+00131	Europe/Andorra
-AE,OM,RE,SC,TF	+2518+05518	Asia/Dubai	UAE, Oman, Réunion, Seychelles, Crozet, Scattered Is
+AE,OM,RE,SC,TF	+2518+05518	Asia/Dubai	Crozet, Scattered Is
 AF	+3431+06912	Asia/Kabul
 AL	+4120+01950	Europe/Tirane
 AM	+4011+04430	Asia/Yerevan
@@ -45,7 +48,7 @@ AQ	-6448-06406	Antarctica/Palmer	Palmer
 AQ	-6734-06808	Antarctica/Rothera	Rothera
 AQ	-720041+0023206	Antarctica/Troll	Troll
 AR	-3436-05827	America/Argentina/Buenos_Aires	Buenos Aires (BA, CF)
-AR	-3124-06411	America/Argentina/Cordoba	Argentina (most areas: CB, CC, CN, ER, FM, MN, SE, SF)
+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)
@@ -56,7 +59,7 @@ AR	-3253-06849	America/Argentina/Mendoza	Mendoza (MZ)
 AR	-3319-06621	America/Argentina/San_Luis	San Luis (SL)
 AR	-5138-06913	America/Argentina/Rio_Gallegos	Santa Cruz (SC)
 AR	-5448-06818	America/Argentina/Ushuaia	Tierra del Fuego (TF)
-AS,UM	-1416-17042	Pacific/Pago_Pago	Samoa, Midway
+AS,UM	-1416-17042	Pacific/Pago_Pago	Midway
 AT	+4813+01620	Europe/Vienna
 AU	-3133+15905	Australia/Lord_Howe	Lord Howe Island
 AU	-5430+15857	Antarctica/Macquarie	Macquarie Island
@@ -101,26 +104,25 @@ 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), Bahamas
+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	+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); 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	+6227-11421	America/Yellowknife	Mountain - NT (central)
 CA	+682059-1334300	America/Inuvik	Mountain - NT (west)
 CA	+5546-12014	America/Dawson_Creek	MST - BC (Dawson Cr, Ft St John)
 CA	+5848-12242	America/Fort_Nelson	MST - BC (Ft Nelson)
 CA	+6043-13503	America/Whitehorse	MST - Yukon (east)
 CA	+6404-13925	America/Dawson	MST - Yukon (west)
 CA	+4916-12307	America/Vancouver	Pacific - BC (most areas)
-CH,DE,LI	+4723+00832	Europe/Zurich	Swiss time
+CH,DE,LI	+4723+00832	Europe/Zurich	Büsingen
 CI,BF,GH,GM,GN,IS,ML,MR,SH,SL,SN,TG	+0519-00402	Africa/Abidjan
 CK	-2114-15946	Pacific/Rarotonga
-CL	-3327-07040	America/Santiago	Chile (most areas)
+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
@@ -129,10 +131,10 @@ CO	+0436-07405	America/Bogota
 CR	+0956-08405	America/Costa_Rica
 CU	+2308-08222	America/Havana
 CV	+1455-02331	Atlantic/Cape_Verde
-CY	+3510+03322	Asia/Nicosia	Cyprus (most areas)
+CY	+3510+03322	Asia/Nicosia	most of Cyprus
 CY	+3507+03357	Asia/Famagusta	Northern Cyprus
 CZ,SK	+5005+01426	Europe/Prague
-DE,DK,NO,SE,SJ	+5230+01322	Europe/Berlin	Germany (most areas), Scandinavia
+DE,DK,NO,SE,SJ	+5230+01322	Europe/Berlin	most of Germany
 DO	+1828-06954	America/Santo_Domingo
 DZ	+3647+00303	Africa/Algiers
 EC	-0210-07950	America/Guayaquil	Ecuador (mainland)
@@ -153,7 +155,7 @@ GB,GG,IM,JE	+513030-0000731	Europe/London
 GE	+4143+04449	Asia/Tbilisi
 GF	+0456-05220	America/Cayenne
 GI	+3608-00521	Europe/Gibraltar
-GL	+6411-05144	America/Nuuk	Greenland (most areas)
+GL	+6411-05144	America/Nuuk	most of Greenland
 GL	+7646-01840	America/Danmarkshavn	National Park (east coast)
 GL	+7029-02158	America/Scoresbysund	Scoresbysund/Ittoqqortoormiit
 GL	+7634-06847	America/Thule	Thule/Pituffik
@@ -183,12 +185,12 @@ JO	+3157+03556	Asia/Amman
 JP	+353916+1394441	Asia/Tokyo
 KE,DJ,ER,ET,KM,MG,SO,TZ,UG,YT	-0117+03649	Africa/Nairobi
 KG	+4254+07436	Asia/Bishkek
-KI,MH,TV,UM,WF	+0125+17300	Pacific/Tarawa	Gilberts, Marshalls, Tuvalu, Wallis & Futuna, Wake
+KI,MH,TV,UM,WF	+0125+17300	Pacific/Tarawa	Gilberts, Marshalls, Wake
 KI	-0247-17143	Pacific/Kanton	Phoenix Islands
 KI	+0152-15720	Pacific/Kiritimati	Line Islands
 KP	+3901+12545	Asia/Pyongyang
 KR	+3733+12658	Asia/Seoul
-KZ	+4315+07657	Asia/Almaty	Kazakhstan (most areas)
+KZ	+4315+07657	Asia/Almaty	most of Kazakhstan
 KZ	+4448+06528	Asia/Qyzylorda	Qyzylorda/Kyzylorda/Kzyl-Orda
 KZ	+5312+06337	Asia/Qostanay	Qostanay/Kostanay/Kustanay
 KZ	+5017+05710	Asia/Aqtobe	Aqtöbe/Aktobe
@@ -205,14 +207,14 @@ MA	+3339-00735	Africa/Casablanca
 MD	+4700+02850	Europe/Chisinau
 MH	+0905+16720	Pacific/Kwajalein	Kwajalein
 MM,CC	+1647+09610	Asia/Yangon
-MN	+4755+10653	Asia/Ulaanbaatar	Mongolia (most areas)
+MN	+4755+10653	Asia/Ulaanbaatar	most of Mongolia
 MN	+4801+09139	Asia/Hovd	Bayan-Ölgii, Govi-Altai, Hovd, Uvs, Zavkhan
 MN	+4804+11430	Asia/Choibalsan	Dornod, Sükhbaatar
 MO	+221150+1133230	Asia/Macau
 MQ	+1436-06105	America/Martinique
 MT	+3554+01431	Europe/Malta
 MU	-2010+05730	Indian/Mauritius
-MV,TF	+0410+07330	Indian/Maldives	Maldives, Kerguelen, St Paul I, Amsterdam I
+MV,TF	+0410+07330	Indian/Maldives	Kerguelen, St Paul I, Amsterdam I
 MX	+1924-09909	America/Mexico_City	Central Mexico
 MX	+2105-08646	America/Cancun	Quintana Roo
 MX	+2058-08937	America/Merida	Campeche, Yucatán
@@ -225,7 +227,7 @@ MX	+2313-10625	America/Mazatlan	Baja California Sur, Nayarit (most areas), Sinal
 MX	+2048-10515	America/Bahia_Banderas	Bahía de Banderas
 MX	+2904-11058	America/Hermosillo	Sonora
 MX	+3232-11701	America/Tijuana	Baja California
-MY,BN	+0133+11020	Asia/Kuching	Sabah, Sarawak, Brunei
+MY,BN	+0133+11020	Asia/Kuching	Sabah, Sarawak
 MZ,BI,BW,CD,MW,RW,ZM,ZW	-2558+03235	Africa/Maputo	Central Africa Time
 NA	-2234+01706	Africa/Windhoek
 NC	-2216+16627	Pacific/Noumea
@@ -237,7 +239,7 @@ NR	-0031+16655	Pacific/Nauru
 NU	-1901-16955	Pacific/Niue
 NZ,AQ	-3652+17446	Pacific/Auckland	New Zealand time
 NZ	-4357-17633	Pacific/Chatham	Chatham Islands
-PA,CA,KY	+0858-07932	America/Panama	EST - Panama, Cayman, ON (Atikokan), NU (Coral H)
+PA,CA,KY	+0858-07932	America/Panama	EST - ON (Atikokan), NU (Coral H)
 PE	-1203-07703	America/Lima
 PF	-1732-14934	Pacific/Tahiti	Society Islands
 PF	-0900-13930	Pacific/Marquesas	Marquesas Islands
@@ -285,13 +287,13 @@ 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); North 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	Arabia, Syowa
-SB,FM	-0932+16012	Pacific/Guadalcanal	Solomons, Pohnpei
+SA,AQ,KW,YE	+2438+04643	Asia/Riyadh	Syowa
+SB,FM	-0932+16012	Pacific/Guadalcanal	Pohnpei
 SD	+1536+03232	Africa/Khartoum
-SG,MY	+0117+10351	Asia/Singapore	Singapore, peninsular Malaysia
+SG,MY	+0117+10351	Asia/Singapore	peninsular Malaysia
 SR	+0550-05510	America/Paramaribo
 SS	+0451+03137	Africa/Juba
 ST	+0020+00644	Africa/Sao_Tome
@@ -299,7 +301,7 @@ SV	+1342-08912	America/El_Salvador
 SY	+3330+03618	Asia/Damascus
 TC	+2128-07108	America/Grand_Turk
 TD	+1207+01503	Africa/Ndjamena
-TH,CX,KH,LA,VN	+1345+10031	Asia/Bangkok	Indochina (most areas)
+TH,CX,KH,LA,VN	+1345+10031	Asia/Bangkok	north Vietnam
 TJ	+3835+06848	Asia/Dushanbe
 TK	-0922-17114	Pacific/Fakaofo
 TL	-0833+12535	Asia/Dili
@@ -308,7 +310,7 @@ TN	+3648+01011	Africa/Tunis
 TO	-210800-1751200	Pacific/Tongatapu
 TR	+4101+02858	Europe/Istanbul
 TW	+2503+12130	Asia/Taipei
-UA	+5026+03031	Europe/Kyiv	Ukraine (most areas)
+UA	+5026+03031	Europe/Kyiv	most of Ukraine
 US	+404251-0740023	America/New_York	Eastern (most areas)
 US	+421953-0830245	America/Detroit	Eastern - MI (most areas)
 US	+381515-0854534	America/Kentucky/Louisville	Eastern - KY (Louisville area)
@@ -328,7 +330,7 @@ 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,CA	+332654-1120424	America/Phoenix	MST - Arizona (except Navajo), Creston BC
+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)
 US	+581807-1342511	America/Juneau	Alaska - Juneau area
@@ -336,13 +338,13 @@ US	+571035-1351807	America/Sitka	Alaska - Sitka area
 US	+550737-1313435	America/Metlakatla	Alaska - Annette Island
 US	+593249-1394338	America/Yakutat	Alaska - Yakutat
 US	+643004-1652423	America/Nome	Alaska (west)
-US	+515248-1763929	America/Adak	Aleutian Islands
-US,UM	+211825-1575130	Pacific/Honolulu	Hawaii
+US	+515248-1763929	America/Adak	Alaska - western Aleutians
+US	+211825-1575130	Pacific/Honolulu	Hawaii
 UY	-345433-0561245	America/Montevideo
 UZ	+3940+06648	Asia/Samarkand	Uzbekistan (west)
 UZ	+4120+06918	Asia/Tashkent	Uzbekistan (east)
 VE	+1030-06656	America/Caracas
-VN	+1045+10640	Asia/Ho_Chi_Minh	Vietnam (south)
+VN	+1045+10640	Asia/Ho_Chi_Minh	south Vietnam
 VU	-1740+16825	Pacific/Efate
 WS	-1350-17144	Pacific/Apia
 ZA,LS,SZ	-2615+02800	Africa/Johannesburg