Update tzdata and zoneinfo to version 2020a.

tzdata/Makefile

@@ -150,6 +150,15 @@ TIME_T_ALTERNATIVES_TAIL = int32_t uint32_t uint64_t
 
 REDO=		posix_right
 
+# Whether to put an "Expires" line in the leapseconds file.
+# Use EXPIRES_LINE=1 to put the line in, 0 to omit it.
+# The EXPIRES_LINE value matters only if REDO's value contains "right".
+# If you change EXPIRES_LINE, remove the leapseconds file before running "make".
+# zic's support for the Expires line was introduced in tzdb 2020a,
+# and EXPIRES_LINE defaults to 0 for now so that the leapseconds file
+# can be given to older zic implementations.
+EXPIRES_LINE=	0
+
 # To install data in text form that has all the information of the TZif data,
 # (optionally incorporating leap second information), use
 #	TZDATA_TEXT=	tzdata.zi leapseconds
@@ -295,35 +304,38 @@ GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \
 # than TM_GMTOFF and TM_ZONE.  However, most of them are standardized.
 # #
 # # To omit or support the external variable "tzname", add one of:
-# #	-DHAVE_TZNAME=0
-# #	-DHAVE_TZNAME=1
+# #	-DHAVE_TZNAME=0 # do not support "tzname"
+# #	-DHAVE_TZNAME=1 # support "tzname", which is defined by system library
+# #	-DHAVE_TZNAME=2 # support and define "tzname"
 # # to the "CFLAGS=" line.  "tzname" is required by POSIX 1988 and later.
 # # If not defined, the code attempts to guess HAVE_TZNAME from other macros.
 # # Warning: unless time_tz is also defined, HAVE_TZNAME=1 can cause
 # # crashes when combined with some platforms' standard libraries,
 # # presumably due to memory allocation issues.
 # #
 # # To omit or support the external variables "timezone" and "daylight", add
-# #	-DUSG_COMPAT=0
-# #	-DUSG_COMPAT=1
+# #	-DUSG_COMPAT=0 # do not support
+# #	-DUSG_COMPAT=1 # support, and variables are defined by system library
+# #	-DUSG_COMPAT=2 # support and define variables
 # # to the "CFLAGS=" line; "timezone" and "daylight" are inspired by
 # # Unix Systems Group code and are required by POSIX 2008 (with XSI) and later.
 # # If not defined, the code attempts to guess USG_COMPAT from other macros.
 # #
 # # To support the external variable "altzone", add
-# #	-DALTZONE
+# #	-DALTZONE=0 # do not support
+# #	-DALTZONE=1 # support "altzone", which is defined by system library
+# #	-DALTZONE=2 # support and define "altzone"
 # # to the end of the "CFLAGS=" line; although "altzone" appeared in
 # # System V Release 3.1 it has not been standardized.
+# # If not defined, the code attempts to guess ALTZONE from other macros.
 #
 # If you want functions that were inspired by early versions of X3J11's work,
 # add
 #	-DSTD_INSPIRED
 # to the end of the "CFLAGS=" line.  This arranges for the functions
 # "tzsetwall", "offtime", "timelocal", "timegm", "timeoff",
 # "posix2time", and "time2posix" to be added to the time conversion library.
-# "tzsetwall" is like "tzset" except that it arranges for local wall clock
-# time (rather than the timezone specified in the TZ environment variable)
-# to be used.
+# "tzsetwall" is deprecated and is intended to be removed soon; see NEWS.
 # "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".
@@ -333,7 +345,6 @@ GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \
 # that gives an offset to use when converting to a time_t.
 # "posix2time" and "time2posix" are described in an included manual page.
 # X3J11's work does not describe any of these functions.
-# Sun has provided "tzsetwall", "timelocal", and "timegm" in SunOS 4.0.
 # These functions may well disappear in future releases of the time
 # conversion package.
 #
@@ -505,11 +516,11 @@ RANLIB=		:
 TZCOBJS=	zic.o
 TZDOBJS=	zdump.o localtime.o asctime.o strftime.o
 DATEOBJS=	date.o localtime.o strftime.o asctime.o
-LIBSRCS=	localtime.c asctime.c difftime.c
-LIBOBJS=	localtime.o asctime.o difftime.o
+LIBSRCS=	localtime.c asctime.c difftime.c strftime.c
+LIBOBJS=	localtime.o asctime.o difftime.o strftime.o
 HEADERS=	tzfile.h private.h
 NONLIBSRCS=	zic.c zdump.c
-NEWUCBSRCS=	date.c strftime.c
+NEWUCBSRCS=	date.c
 SOURCES=	$(HEADERS) $(LIBSRCS) $(NONLIBSRCS) $(NEWUCBSRCS) \
 			tzselect.ksh workman.sh
 MANS=		newctime.3 newstrftime.3 newtzset.3 time2posix.3 \
@@ -651,7 +662,8 @@ yearistype:	yearistype.sh
 		chmod +x yearistype
 
 leapseconds:	$(LEAP_DEPS)
-		$(AWK) -f leapseconds.awk leap-seconds.list >$@.out
+		$(AWK) -v EXPIRES_LINE=$(EXPIRES_LINE) \
+		  -f leapseconds.awk leap-seconds.list >$@.out
 		mv $@.out $@
 
 # Arguments to pass to submakes of install_data.

tzdata/NEWS

@@ -1,5 +1,87 @@
 News for the tz database
 
+Release 2020a - 2020-04-23 16:03:47 -0700
+
+  Briefly:
+    Morocco springs forward on 2020-05-31, not 2020-05-24.
+    Canada's Yukon advanced to -07 year-round on 2020-03-08.
+    America/Nuuk renamed from America/Godthab.
+    zic now supports expiration dates for leap second lists.
+
+  Changes to future timestamps
+
+    Morocco's second spring-forward transition in 2020 will be May 31,
+    not May 24 as predicted earlier.  (Thanks to Semlali Naoufal.)
+    Adjust future-year predictions to use the first Sunday after the
+    day after Ramadan, not the first Sunday after Ramadan.
+
+    Canada's Yukon, represented by America/Whitehorse and
+    America/Dawson, advanced to -07 year-round, beginning with its
+    spring-forward transition on 2020-03-08, and will not fall back on
+    2020-11-01.  Although a government press release calls this
+    "permanent Pacific Daylight Saving Time", we prefer MST for
+    consistency with nearby Dawson Creek, Creston, and Fort Nelson.
+    (Thanks to Tim Parenti.)
+
+  Changes to past timestamps
+
+    Shanghai observed DST in 1919.  (Thanks to Phake Nick.)
+
+  Changes to timezone identifiers
+
+    To reflect current usage in English better, America/Godthab has
+    been renamed to America/Nuuk.  A backwards-compatibility link
+    remains for the old name.
+
+  Changes to code
+
+    localtime.c no longer mishandles timestamps after the last
+    transition in a TZif file with leap seconds and with daylight
+    saving time transitions projected into the indefinite future.
+    For example, with TZ='America/Los_Angeles' with leap seconds,
+    zdump formerly reported a DST transition on 2038-03-14
+    from 01:59:32.999... to 02:59:33 instead of the correct transition
+    from 01:59:59.999... to 03:00:00.
+
+    zic -L now supports an Expires line in the leapseconds file, and
+    truncates the TZif output accordingly.  This propagates leap
+    second expiration information into the TZif file, and avoids the
+    abovementioned localtime.c bug as well as similar bugs present in
+    many client implementations.  If no Expires line is present, zic
+    -L instead truncates the TZif output based on the #expires comment
+    present in leapseconds files distributed by tzdb 2018f and later;
+    however, this usage is obsolescent.  For now, the distributed
+    leapseconds file has an Expires line that is commented out, so
+    that the file can be fed to older versions of zic which ignore the
+    commented-out line.  Future tzdb distributions are planned to
+    contain a leapseconds file with an Expires line.
+
+    The configuration macros HAVE_TZNAME and USG_COMPAT should now be
+    set to 1 if the system library supports the feature, and 2 if not.
+    As before, these macros are nonzero if tzcode should support the
+    feature, zero otherwise.
+
+    The configuration macro ALTZONE now has the same values with the
+    same meaning as HAVE_TZNAME and USG_COMPAT.
+
+    The code's defense against CRLF in leap-seconds.list is now
+    portable to POSIX awk.  (Problem reported by Deborah Goldsmith.)
+
+    Although the undocumented tzsetwall function is not changed in
+    this release, it is now deprecated in preparation for removal in
+    future releases.  Due to POSIX requirements, tzsetwall has not
+    worked for some time.  Any code that uses it should instead use
+    tzalloc(NULL) or, if portability trumps thread-safety, should
+    unset the TZ environment variable.
+
+  Changes to commentary
+
+    The Îles-de-la-Madeleine and the Listuguj reserve are noted as
+    following America/Halifax, and comments about Yukon's "south" and
+    "north" have been corrected to say "east" and "west".  (Thanks to
+    Jeffery Nichols.)
+
+
 Release 2019c - 2019-09-11 08:59:48 -0700
 
   Briefly:

tzdata/africa

@@ -867,19 +867,25 @@ Zone Indian/Mauritius	3:50:00 -	LMT	1907 # Port Louis
 # Morocco will be on GMT starting from Sunday, May 5th 2019 at 3am.
 # The switch to GMT+1 will occur on Sunday, June 9th 2019 at 2am....
 # http://fr.le360.ma/societe/voici-la-date-du-retour-a-lheure-legale-au-maroc-188222
-#
-# From Paul Eggert (2019-05-20):
-# This agrees with our 2018-11-01 guess that the Moroccan government
-# would continue the practice of falling back at 03:00 the last Sunday
-# before Ramadan, and of springing forward at 02:00 the first Sunday after
-# Ramadan, as this has been the practice since 2012.  To implement this,
-# transition dates for 2019 through 2087 were determined by running the
-# following program under GNU Emacs 26.2.
-# (let ((islamic-year 1440))
+
+# From Semlali Naoufal (2020-04-14):
+# Following the announcement by the Moroccan government, the switch to
+# GMT time will take place on Sunday, April 19, 2020 from 3 a.m. and
+# the return to GMT+1 time will take place on Sunday, May 31, 2020 at 2 a.m....
+# https://maroc-diplomatique.net/maroc-le-retour-a-lheure-gmt-est-prevu-dimanche-prochain/
+# http://aujourdhui.ma/actualite/gmt1-retour-a-lheure-normale-dimanche-prochain-1
+#
+# From Paul Eggert (2020-04-14):
+# 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 the day after Ramadan.  To implement this,
+# transition dates for 2021 through 2087 were determined by running
+# the following program under GNU Emacs 26.3.
+# (let ((islamic-year 1442))
 #   (require 'cal-islam)
 #   (while (< islamic-year 1511)
 #     (let ((a (calendar-islamic-to-absolute (list 9 1 islamic-year)))
-#           (b (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))
@@ -939,7 +945,7 @@ Rule	Morocco	2018	only	-	Jun	17	 2:00	1:00	-
 Rule	Morocco	2019	only	-	May	 5	 3:00	-1:00	-
 Rule	Morocco	2019	only	-	Jun	 9	 2:00	0	-
 Rule	Morocco	2020	only	-	Apr	19	 3:00	-1:00	-
-Rule	Morocco	2020	only	-	May	24	 2:00	0	-
+Rule	Morocco	2020	only	-	May	31	 2:00	0	-
 Rule	Morocco	2021	only	-	Apr	11	 3:00	-1:00	-
 Rule	Morocco	2021	only	-	May	16	 2:00	0	-
 Rule	Morocco	2022	only	-	Mar	27	 3:00	-1:00	-
@@ -955,7 +961,7 @@ Rule	Morocco	2026	only	-	Mar	22	 2:00	0	-
 Rule	Morocco	2027	only	-	Feb	 7	 3:00	-1:00	-
 Rule	Morocco	2027	only	-	Mar	14	 2:00	0	-
 Rule	Morocco	2028	only	-	Jan	23	 3:00	-1:00	-
-Rule	Morocco	2028	only	-	Feb	27	 2:00	0	-
+Rule	Morocco	2028	only	-	Mar	 5	 2:00	0	-
 Rule	Morocco	2029	only	-	Jan	14	 3:00	-1:00	-
 Rule	Morocco	2029	only	-	Feb	18	 2:00	0	-
 Rule	Morocco	2029	only	-	Dec	30	 3:00	-1:00	-
@@ -971,7 +977,7 @@ Rule	Morocco	2033	only	-	Dec	25	 2:00	0	-
 Rule	Morocco	2034	only	-	Nov	 5	 3:00	-1:00	-
 Rule	Morocco	2034	only	-	Dec	17	 2:00	0	-
 Rule	Morocco	2035	only	-	Oct	28	 3:00	-1:00	-
-Rule	Morocco	2035	only	-	Dec	 2	 2:00	0	-
+Rule	Morocco	2035	only	-	Dec	 9	 2:00	0	-
 Rule	Morocco	2036	only	-	Oct	19	 3:00	-1:00	-
 Rule	Morocco	2036	only	-	Nov	23	 2:00	0	-
 Rule	Morocco	2037	only	-	Oct	 4	 3:00	-1:00	-
@@ -987,7 +993,7 @@ Rule	Morocco	2041	only	-	Sep	29	 2:00	0	-
 Rule	Morocco	2042	only	-	Aug	10	 3:00	-1:00	-
 Rule	Morocco	2042	only	-	Sep	21	 2:00	0	-
 Rule	Morocco	2043	only	-	Aug	 2	 3:00	-1:00	-
-Rule	Morocco	2043	only	-	Sep	 6	 2:00	0	-
+Rule	Morocco	2043	only	-	Sep	13	 2:00	0	-
 Rule	Morocco	2044	only	-	Jul	24	 3:00	-1:00	-
 Rule	Morocco	2044	only	-	Aug	28	 2:00	0	-
 Rule	Morocco	2045	only	-	Jul	 9	 3:00	-1:00	-
@@ -1003,7 +1009,7 @@ Rule	Morocco	2049	only	-	Jul	 4	 2:00	0	-
 Rule	Morocco	2050	only	-	May	15	 3:00	-1:00	-
 Rule	Morocco	2050	only	-	Jun	26	 2:00	0	-
 Rule	Morocco	2051	only	-	May	 7	 3:00	-1:00	-
-Rule	Morocco	2051	only	-	Jun	11	 2:00	0	-
+Rule	Morocco	2051	only	-	Jun	18	 2:00	0	-
 Rule	Morocco	2052	only	-	Apr	28	 3:00	-1:00	-
 Rule	Morocco	2052	only	-	Jun	 2	 2:00	0	-
 Rule	Morocco	2053	only	-	Apr	13	 3:00	-1:00	-
@@ -1019,7 +1025,7 @@ Rule	Morocco	2057	only	-	Apr	 8	 2:00	0	-
 Rule	Morocco	2058	only	-	Feb	17	 3:00	-1:00	-
 Rule	Morocco	2058	only	-	Mar	31	 2:00	0	-
 Rule	Morocco	2059	only	-	Feb	 9	 3:00	-1:00	-
-Rule	Morocco	2059	only	-	Mar	16	 2:00	0	-
+Rule	Morocco	2059	only	-	Mar	23	 2:00	0	-
 Rule	Morocco	2060	only	-	Feb	 1	 3:00	-1:00	-
 Rule	Morocco	2060	only	-	Mar	 7	 2:00	0	-
 Rule	Morocco	2061	only	-	Jan	16	 3:00	-1:00	-
@@ -1029,13 +1035,13 @@ 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	-
-Rule	Morocco	2064	only	-	Jan	20	 2:00	0	-
+Rule	Morocco	2064	only	-	Jan	27	 2:00	0	-
 Rule	Morocco	2064	only	-	Dec	 7	 3:00	-1:00	-
 Rule	Morocco	2065	only	-	Jan	11	 2:00	0	-
 Rule	Morocco	2065	only	-	Nov	22	 3:00	-1:00	-
 Rule	Morocco	2066	only	-	Jan	 3	 2:00	0	-
 Rule	Morocco	2066	only	-	Nov	14	 3:00	-1:00	-
-Rule	Morocco	2066	only	-	Dec	19	 2:00	0	-
+Rule	Morocco	2066	only	-	Dec	26	 2:00	0	-
 Rule	Morocco	2067	only	-	Nov	 6	 3:00	-1:00	-
 Rule	Morocco	2067	only	-	Dec	11	 2:00	0	-
 Rule	Morocco	2068	only	-	Oct	21	 3:00	-1:00	-
@@ -1045,13 +1051,13 @@ 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	-
-Rule	Morocco	2071	only	-	Oct	25	 2:00	0	-
+Rule	Morocco	2071	only	-	Nov	 1	 2:00	0	-
 Rule	Morocco	2072	only	-	Sep	11	 3:00	-1:00	-
 Rule	Morocco	2072	only	-	Oct	16	 2:00	0	-
 Rule	Morocco	2073	only	-	Aug	27	 3:00	-1:00	-
 Rule	Morocco	2073	only	-	Oct	 8	 2:00	0	-
 Rule	Morocco	2074	only	-	Aug	19	 3:00	-1:00	-
-Rule	Morocco	2074	only	-	Sep	23	 2:00	0	-
+Rule	Morocco	2074	only	-	Sep	30	 2:00	0	-
 Rule	Morocco	2075	only	-	Aug	11	 3:00	-1:00	-
 Rule	Morocco	2075	only	-	Sep	15	 2:00	0	-
 Rule	Morocco	2076	only	-	Jul	26	 3:00	-1:00	-
@@ -1061,7 +1067,7 @@ 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	-
-Rule	Morocco	2079	only	-	Jul	30	 2:00	0	-
+Rule	Morocco	2079	only	-	Aug	 6	 2:00	0	-
 Rule	Morocco	2080	only	-	Jun	16	 3:00	-1:00	-
 Rule	Morocco	2080	only	-	Jul	21	 2:00	0	-
 Rule	Morocco	2081	only	-	Jun	 1	 3:00	-1:00	-
@@ -1077,7 +1083,7 @@ 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	-
-Rule	Morocco	2087	only	-	May	 4	 2:00	0	-
+Rule	Morocco	2087	only	-	May	11	 2:00	0	-
 # For dates after the somewhat-arbitrary cutoff of 2087, assume that
 # Morocco will no longer observe DST.  At some point this table will
 # need to be extended, though quite possibly Morocco will change the
@@ -1179,7 +1185,7 @@ Link Africa/Maputo Africa/Lusaka	# Zambia
 Rule	Namibia	1994	only	-	Mar	21	0:00	-1:00	WAT
 Rule	Namibia	1994	2017	-	Sep	Sun>=1	2:00	0	CAT
 Rule	Namibia	1995	2017	-	Apr	Sun>=1	2:00	-1:00	WAT
-# Rearguard section, for parsers that do not support negative DST.
+# Rearguard section, for parsers lacking negative DST; see ziguard.awk.
 #Rule	Namibia	1994	only	-	Mar	21	0:00	0	WAT
 #Rule	Namibia	1994	2017	-	Sep	Sun>=1	2:00	1:00	CAT
 #Rule	Namibia	1995	2017	-	Apr	Sun>=1	2:00	0	WAT
@@ -1193,7 +1199,7 @@ Zone	Africa/Windhoek	1:08:24 -	LMT	1892 Feb 8
 			2:00	-	SAST	1990 Mar 21 # independence
 # Vanguard section, for zic and other parsers that support negative DST.
 			2:00	Namibia	%s
-# Rearguard section, for parsers that do not support negative DST.
+# Rearguard section, for parsers lacking negative DST; see ziguard.awk.
 #			2:00	-	CAT	1994 Mar 21  0:00
 # From Paul Eggert (2017-04-07):
 # The official date of the 2017 rule change was 2017-10-24.  See: