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contrib/tzdata: import tzdata 2021b

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Merge commit 'a5725262945a2971af3b808088217fe975e8364e'

Changes: https://github.com/eggert/tz/blob/2021b/NEWS

MFC after:	3 days
This commit is contained in:
Philip Paeps 2021-09-26 14:45:39 +08:00
parent cb17f4a6bd a572526294
commit 94c2d487f1
20 changed files with 1094 additions and 574 deletions
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15
contrib/tzdata/CONTRIBUTING
View file

@ -26,8 +26,11 @@ to work well. Additions to data should contain commentary citing
reliable sources as justification. Citations should use https: URLs
if available.
For changes that fix sensitive security-related bugs, please see the
file SECURITY.
Please submit changes against either the latest release in
<https://www.iana.org/time-zones> or the master branch of the development
<https://www.iana.org/time-zones> or the main branch of the development
repository. The latter is preferred. If you use Git the following
workflow may be helpful:
@ -36,9 +39,9 @@ workflow may be helpful:
git clone https://github.com/eggert/tz.git
cd tz
* Get current with the master branch.
* Get current with the main branch.
git checkout master
git checkout main
git pull
* Switch to a new branch for the changes. Choose a different
@ -70,17 +73,17 @@ workflow may be helpful:
* Create patch files 0001-*, 0002-*, ...
git format-patch master
git format-patch main
* After reviewing the patch files, send the patches to tz@iana.org
for others to review.
git send-email master
git send-email main
For an archived example of such an email, see
<https://mm.icann.org/pipermail/tz/2018-February/026122.html>.
* Start anew by getting current with the master branch again
* Start anew by getting current with the main branch again
(the second step above).
Please do not create issues or pull requests on GitHub, as the

43
contrib/tzdata/Makefile
View file

@ -45,9 +45,9 @@ LOCALTIME= GMT
#
# Any other value for POSIXRULES is obsolete and should not be relied on, as: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 in the tzdb implementation for timestamps after 2037.
# * It is incompatible with 'zic -b slim' if POSIXRULES specifies transitions
# at standard time or UT rather than at local time.
# * 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.
#
@ -122,8 +122,8 @@ LIBDIR = $(TOPDIR)/$(USRDIR)/lib
# Types to try, as an alternative to time_t.
TIME_T_ALTERNATIVES = $(TIME_T_ALTERNATIVES_HEAD) $(TIME_T_ALTERNATIVES_TAIL)
TIME_T_ALTERNATIVES_HEAD = int64_t
TIME_T_ALTERNATIVES_TAIL = int32_t uint32_t uint64_t
TIME_T_ALTERNATIVES_HEAD = int_least64_t
TIME_T_ALTERNATIVES_TAIL = int_least32_t uint_least32_t uint_least64_t
# What kind of TZif data files to generate. (TZif is the binary time
# zone data format that zic generates; see Internet RFC 8536.)
@ -152,8 +152,10 @@ REDO= posix_right
# 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.
# and was modified in tzdb 2021b to generate version 4 TZif files.
# EXPIRES_LINE defaults to 0 for now so that the leapseconds file
# can be given to pre-2020a zic implementations and so that TZif files
# built by newer zic implementations can be read by pre-2021b libraries.
EXPIRES_LINE= 0
# To install data in text form that has all the information of the TZif data,
@ -210,6 +212,7 @@ LDLIBS=
# -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
# localtime_rz can make zdump significantly faster, but is nonstandard.
# -DHAVE_MALLOC_ERRNO=0 if malloc etc. do not set errno on failure.
# -DHAVE_POSIX_DECLS=0 if your system's include files do not declare
# functions like 'link' or variables like 'tzname' required by POSIX
# -DHAVE_SNPRINTF=0 if your system lacks the snprintf function
@ -220,7 +223,6 @@ LDLIBS=
# -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 your compiler lacks a <sys/stat.h>
# -DHAVE_SYS_WAIT_H=0 if your compiler lacks a <sys/wait.h>
# -DHAVE_TZSET=0 if your system lacks a tzset function
# -DHAVE_UNISTD_H=0 if your compiler lacks a <unistd.h>
# -Dlocale_t=XXX if your system uses XXX instead of locale_t
@ -257,22 +259,26 @@ LDLIBS=
GCC_INSTRUMENT = \
-fsanitize=undefined -fsanitize-address-use-after-scope \
-fsanitize-undefined-trap-on-error -fstack-protector
# Omit -fanalyzer from GCC_DEBUG_FLAGS, as it makes GCC too slow.
GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \
$(GCC_INSTRUMENT) \
-Wall -Wextra \
-Walloc-size-larger-than=100000 -Warray-bounds=2 \
-Wbad-function-cast -Wcast-align=strict -Wdate-time \
-Wdeclaration-after-statement -Wdouble-promotion \
-Wduplicated-branches -Wduplicated-cond \
-Wformat=2 -Wformat-overflow=2 -Wformat-signedness -Wformat-truncation \
-Winit-self -Wjump-misses-init -Wlogical-op \
-Winit-self -Wlogical-op \
-Wmissing-declarations -Wmissing-prototypes -Wnested-externs \
-Wnull-dereference \
-Wold-style-definition -Woverlength-strings -Wpointer-arith \
-Wshadow -Wshift-overflow=2 -Wstrict-prototypes -Wstringop-overflow=4 \
-Wshadow -Wshift-overflow=2 -Wstrict-overflow \
-Wstrict-prototypes -Wstringop-overflow=4 \
-Wstringop-truncation -Wsuggest-attribute=cold \
-Wsuggest-attribute=const -Wsuggest-attribute=format \
-Wsuggest-attribute=malloc \
-Wsuggest-attribute=noreturn -Wsuggest-attribute=pure \
-Wtrampolines -Wundef -Wuninitialized -Wunused \
-Wtrampolines -Wundef -Wuninitialized -Wunused-macros \
-Wvariadic-macros -Wvla -Wwrite-strings \
-Wno-address -Wno-format-nonliteral -Wno-sign-compare \
-Wno-type-limits -Wno-unused-parameter
@ -523,7 +529,7 @@ TZS_YEAR= 2050
TZS_CUTOFF_FLAG= -c $(TZS_YEAR)
TZS= to$(TZS_YEAR).tzs
TZS_NEW= to$(TZS_YEAR)new.tzs
TZS_DEPS= $(PRIMARY_YDATA) asctime.c localtime.c \
TZS_DEPS= $(YDATA) asctime.c localtime.c \
private.h tzfile.h zdump.c zic.c
# EIGHT_YARDS is just a yard short of the whole ENCHILADA.
EIGHT_YARDS = $(COMMON) $(DOCS) $(SOURCES) $(DATA) $(MISC) tzdata.zi
@ -796,9 +802,10 @@ check_links: checklinks.awk $(TDATA_TO_CHECK) tzdata.zi
$(AWK) -f checklinks.awk tzdata.zi
touch $@
check_tables: checktab.awk $(PRIMARY_YDATA) $(ZONETABLES)
check_tables: checktab.awk $(YDATA) backward $(ZONETABLES)
for tab in $(ZONETABLES); do \
$(AWK) -f checktab.awk -v zone_table=$$tab $(PRIMARY_YDATA) \
test "$$tab" = zone.tab && links='$(BACKWARD)' || links=''; \
$(AWK) -f checktab.awk -v zone_table=$$tab $(YDATA) $$links \
|| exit; \
done
touch $@
@ -952,6 +959,12 @@ check_public: $(VERSION_DEPS)
public.dir/zic -v -d public.dir/zoneinfo $$i 2>&1 || exit; \
done
public.dir/zic -v -d public.dir/zoneinfo-all $(TDATA_TO_CHECK)
:
: Also check 'backzone' syntax.
rm public.dir/main.zi
cd public.dir && $(MAKE) PACKRATDATA=backzone main.zi
public.dir/zic -d public.dir/zoneinfo main.zi
:
rm -fr public.dir
touch $@
@ -964,7 +977,7 @@ $(TIME_T_ALTERNATIVES): $(VERSION_DEPS)
mkdir $@.dir
ln $(VERSION_DEPS) $@.dir
case $@ in \
int32_t) range=-2147483648,2147483648;; \
int*32_t) range=-2147483648,2147483648;; \
u*) range=0,4294967296;; \
*) range=-4294967296,4294967296;; \
esac && \

229
contrib/tzdata/NEWS
View file

@ -1,5 +1,228 @@
News for the tz database
Release 2021b - 2021-09-24 16:23:00 -0700
Briefly:
Jordan now starts DST on February's last Thursday.
Samoa no longer observes DST.
Merge more location-based Zones whose timestamps agree since 1970.
Move some backward-compatibility links to 'backward'.
Rename Pacific/Enderbury to Pacific/Kanton.
Correct many pre-1993 transitions in Malawi, Portugal, etc.
zic now creates each output file or link atomically.
zic -L no longer omits the POSIX TZ string in its output.
zic fixes for truncation and leap second table expiration.
zic now follows POSIX for TZ strings using all-year DST.
Fix some localtime crashes and bugs in obscure cases.
zdump -v now outputs more-useful boundary cases.
tzfile.5 better matches a draft successor to RFC 8536.
A new file SECURITY.
This release is prompted by recent announcements by Jordan and Samoa.
It incorporates many other changes that had accumulated since 2021a.
However, it omits most proposed changes that merged all Zones
agreeing since 1970, as concerns were raised about doing too many of
these changes at once. It does keeps some of these changes in the
interest of making tzdb more equitable one step at a time; see
"Merge more location-based Zones" below.
Changes to future timestamps
Jordan now starts DST on February's last Thursday.
(Thanks to Steffen Thorsen.)
Samoa no longer observes DST. (Thanks to Geoffrey D. Bennett.)
Changes to zone name
Rename Pacific/Enderbury to Pacific/Kanton. When we added
Enderbury in 1993, we did not know that it is uninhabited and that
Kanton (population two dozen) is the only inhabited location in
that timezone. The old name is now a backward-compatility link.
Changes to past timestamps
Correct many pre-1993 transitions, fixing entries originally
derived from Shanks, Whitman, and Mundell. The fixes include:
- Barbados: standard time was introduced in 1911, not 1932; and
DST was observed in 1942-1944
- Cook Islands: In 1899 they switched from east to west of GMT,
celebrating Christmas for two days. They (and Niue) switched
to standard time in 1952, not 1901.
- Guyana: corrected LMT for Georgetown; the introduction of
standard time in 1911, not 1915; and corrections to 1975 and
1992 transitions
- Kanton: uninhabited before 1937-08-31
- Niue: only observed -11:20 from 1952 through 1964, then went to
-11 instead of -11:30
- Portugal: DST was observed in 1950
- Tonga: corrected LMT; the introduction of standard time in 1945,
not 1901; and corrections to the transition from +12:20 to +13
in 1961, not 1941
Additional fixes to entries in the 'backzone' file include:
- Enderbury: inhabited only 1860/1885 and 1938-03-06/1942-02-09
- The Gambia: 1933 and 1942 transitions
- Malawi: several 1911 through 1925 transitions
- Sierra Leone: several 1913 through 1941 transitions, and DST
was NOT observed in 1957 through 1962
(Thanks to P Chan, Michael Deckers, Alexander Krivenyshev and
Alois Treindl.)
Merge more location-based Zones whose timestamps agree since 1970,
as pre-1970 timestamps are out of scope. This is part of a
process that has been ongoing since 2013. This does not affect
post-1970 timestamps, and timezone historians who build with 'make
PACKRATDATA=backzone' should see no changes to pre-1970 timestamps.
When merging, keep the most-populous location's data, and move
data for other locations to 'backzone' with a backward
link in 'backward'. For example, move America/Creston data to
'backzone' with a link in 'backward' from America/Phoenix because
the two timezones' timestamps agree since 1970; this change
affects some pre-1968 timestamps in America/Creston because
Creston and Phoenix disagreed before 1968. The affected Zones
are Africa/Accra, America/Atikokan, America/Blanc-Sablon,
America/Creston, America/Curacao, America/Nassau,
America/Port_of_Spain, Antarctica/DumontDUrville, and
Antarctica/Syowa.
Changes to maintenance procedure
The new file SECURITY covers how to report security-related bugs.
Several backward-compatibility links have been moved to the
'backward' file. These links, which range from Africa/Addis_Ababa
to Pacific/Saipan, are only for compatibility with now-obsolete
guidelines suggesting an entry for every ISO 3166 code.
The intercontinental convenience links Asia/Istanbul and
Europe/Nicosia have also been moved to 'backward'.
Changes to code
zic now creates each output file or link atomically,
possibly by creating a temporary file and then renaming it.
This avoids races where a TZ setting would temporarily stop
working while zic was installing a replacement file or link.
zic -L no longer omits the POSIX TZ string in its output.
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
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
seconds error than with an hour error, so zic -L no longer
truncates output in this way.
Instead, when zic -L is given the "Expires" directive, it now
outputs the expiration by appending a no-change entry to the leap
second table. Although this should work well with most TZif
readers, it does not conform to Internet RFC 8536 and some pickier
clients (including tzdb 2017c through 2021a) reject it, so
"Expires" directives are currently disabled by default. To enable
them, set the EXPIRES_LINE Makefile variable. If a TZif file uses
this new feature it is marked with a new TZif version number 4,
a format intended to be documented in a successor to RFC 8536.
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
information.
The TZif reader now allows the leap second table to begin with a
correction other than -1 or +1, and to contain adjacent
transitions with equal corrections. This supports TZif version 4.
The TZif reader now lets leap seconds occur less than 28 days
apart. This supports possible future TZif extensions.
Fix bug that caused 'localtime' etc. to crash when TZ was
set to a all-year DST string like "EST5EDT4,0/0,J365/25" that does
not conform to POSIX but does conform to Internet RFC 8536.
Fix another bug that caused 'localtime' etc. to crash when TZ was
set to a POSIX-conforming but unusual TZ string like
"EST5EDT4,0/0,J365/0", where almost all the year is DST.
Fix yet another bug that caused 'localtime' etc. to mishandle slim
TZif files containing leap seconds after the last explicit
transition in the table, or when handling far-future timestamps
in slim TZif files lacking leap seconds.
Fix localtime misbehavior involving positive leap seconds.
This change affects only behavior for "right" system time,
which contains leap seconds, and only if the UT offset is
not a multiple of 60 seconds when a positive leap second occurs.
(No such timezone exists in tzdb, luckily.) Without the fix,
the timestamp was ambiguous during a positive leap second.
With the fix, any seconds occurring after a positive leap second
and within the same localtime minute are counted through 60, not
through 59; their UT offset (tm_gmtoff) is the same as before.
Here is how the fix affects timestamps in a timezone with UT
offset +01:23:45 (5025 seconds) and with a positive leap second at
1972-06-30 23:59:60 UTC (78796800):
time_t without the fix with the fix
78796800 1972-07-01 01:23:45 1972-07-01 01:23:45 (leap second)
78796801 1972-07-01 01:23:45 1972-07-01 01:23:46
...
78796815 1972-07-01 01:23:59 1972-07-01 01:23:60
78796816 1972-07-01 01:24:00 1972-07-01 01:24:00
Fix an unlikely bug that caused 'localtime' etc. to misbehave if
civil time changes a few seconds before time_t wraps around, when
leap seconds are enabled.
Fix bug in zic -r; in some cases, the dummy time type after the
last time transition disagreed with the TZ string, contrary to
Internet RFC 8563 section 3.3.
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
leap second that has a nonpositive correction.
zic -r now reports an error if given rolling leap seconds, as this
usage has never generally worked and is evidently unused.
zic now generates a POSIX-conforming TZ string for TZif files
where all-year DST is predicted for the indefinite future.
For example, for all-year Eastern Daylight Time, zic now generates
"XXX3EDT4,0/0,J365/23" where it previously generated
"EST5EDT,0/0,J365/25" or "". (Thanks to Michael Deckers for
noting the possibility of POSIX conformance.)
zic.c no longer requires sys/wait.h (thanks to spazmodius for
noting it wasn't needed).
When reading slim TZif files, zdump no longer mishandles leap
seconds on the rare platforms where time_t counts leap seconds,
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
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.)
zdump's -c and -t options are now consistently inclusive for the
lower time bound and exclusive for the upper. Formerly they were
inconsistent. (Confusion noted by Martin Burnicki.)
Changes to build procedure
You can now compile with -DHAVE_MALLOC_ERRNO=0 to port to
non-POSIX hosts where malloc doesn't set errno.
(Problem reported by Jan Engelhardt.)
Changes to documentation
tzfile.5 better matches a draft successor to RFC 8536
<https://datatracker.ietf.org/doc/draft-murchison-rfc8536bis/01/>.
Release 2021a - 2021-01-24 10:54:57 -0800
Changes to future timestamps
@ -31,7 +254,7 @@ Release 2020e - 2020-12-22 15:14:34 -0800
Correct many pre-1986 transitions, fixing entries originally
derived from Shanks. The fixes include:
- Australia: several 1917 through 1971 transitions
- Bahamas: several 1941 through 1945 transitions
- The Bahamas: several 1941 through 1945 transitions
- Bermuda: several 1917 through 1956 transitions
- Belize: several 1942 through 1968 transitions
- Ghana: several 1915 through 1956 transitions
@ -825,8 +1048,8 @@ Release 2018d - 2018-03-22 07:05:46 -0700
Institute in Montevideo.
(Thanks to Jeremie Bonjour, Tim Parenti, and Michael Deckers.)
Enderbury and Kiritimati skipped New Year's Eve 1994, not
New Year's Day 1995. (Thanks to Kerry Shetline.)
East Kiribati skipped New Year's Eve 1994, not New Year's Day 1995.
(Thanks to Kerry Shetline.)
Fix the 1912-01-01 transition for Portugal and its colonies.
This transition was at 00:00 according to the new UT offset, not

135
contrib/tzdata/africa
View file

@ -30,9 +30,6 @@
# Milne J. Civil time. Geogr J. 1899 Feb;13(2):173-94.
# https://www.jstor.org/stable/1774359
#
# A reliable and entertaining source about time zones is
# Derek Howse, Greenwich time and longitude, Philip Wilson Publishers (1997).
#
# European-style abbreviations are commonly used along the Mediterranean.
# For sub-Saharan Africa abbreviations were less standardized.
# Previous editions of this database used WAT, CAT, SAT, and EAT
@ -153,15 +150,6 @@ Zone Africa/Ndjamena 1:00:12 - LMT 1912 # N'Djamena
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Africa/Abidjan -0:16:08 - LMT 1912
0:00 - GMT
Link Africa/Abidjan Africa/Bamako # Mali
Link Africa/Abidjan Africa/Banjul # Gambia
Link Africa/Abidjan Africa/Conakry # Guinea
Link Africa/Abidjan Africa/Dakar # Senegal
Link Africa/Abidjan Africa/Freetown # Sierra Leone
Link Africa/Abidjan Africa/Lome # Togo
Link Africa/Abidjan Africa/Nouakchott # Mauritania
Link Africa/Abidjan Africa/Ouagadougou # Burkina Faso
Link Africa/Abidjan Atlantic/St_Helena # St Helena
# Djibouti
# See Africa/Nairobi.
@ -381,93 +369,8 @@ Zone Africa/Cairo 2:05:09 - LMT 1900 Oct
# Gabon
# See Africa/Lagos.
# Gambia
# See Africa/Abidjan.
# The Gambia
# Ghana
# From P Chan (2020-11-20):
# Interpretation Amendment Ordinance, 1915 (No.24 of 1915) [1915-11-02]
# Ordinances of the Gold Coast, Ashanti, Northern Territories 1915, p 69-71
# https://books.google.com/books?id=ErA-AQAAIAAJ&pg=PA70
# This Ordinance added "'Time' shall mean Greenwich Mean Time" to the
# Interpretation Ordinance, 1876.
#
# Determination of the Time Ordinance, 1919 (No. 18 of 1919) [1919-11-24]
# Ordinances of the Gold Coast, Ashanti, Northern Territories 1919, p 75-76
# https://books.google.com/books?id=MbA-AQAAIAAJ&pg=PA75
# This Ordinance removed the previous definition of time and introduced DST.
#
# Time Determination Ordinance (Cap. 214)
# The Laws of the Gold Coast (including Togoland Under British Mandate)
# Vol. II (1937), p 2328
# https://books.google.com/books?id=Z7M-AQAAIAAJ&pg=PA2328
# Revised edition of the 1919 Ordinance.
#
# Time Determination (Amendment) Ordinance, 1940 (No. 9 of 1940) [1940-04-06]
# Annual Volume of the Laws of the Gold Coast:
# Containing All Legislation Enacted During Year 1940, p 22
# https://books.google.com/books?id=1ao-AQAAIAAJ&pg=PA22
# This Ordinance changed the forward transition from September to May.
#
# Defence (Time Determination Ordinance Amendment) Regulations, 1942
# (Regulations No. 6 of 1942) [1942-01-31, commenced on 1942-02-08]
# Annual Volume of the Laws of the Gold Coast:
# Containing All Legislation Enacted During Year 1942, p 48
# https://books.google.com/books?id=Das-AQAAIAAJ&pg=PA48
# These regulations advanced the [standard] time by thirty minutes.
#
# Defence (Time Determination Ordinance Amendment (No.2)) Regulations,
# 1942 (Regulations No. 28 of 1942) [1942-04-25]
# Annual Volume of the Laws of the Gold Coast:
# Containing All Legislation Enacted During Year 1942, p 87
# https://books.google.com/books?id=Das-AQAAIAAJ&pg=PA87
# These regulations abolished DST and changed the time to GMT+0:30.
#
# Defence (Revocation) (No.4) Regulations, 1945 (Regulations No. 45 of
# 1945) [1945-10-24, commenced on 1946-01-06]
# Annual Volume of the Laws of the Gold Coast:
# Containing All Legislation Enacted During Year 1945, p 256
# https://books.google.com/books?id=9as-AQAAIAAJ&pg=PA256
# These regulations revoked the previous two sets of Regulations.
#
# Time Determination (Amendment) Ordinance, 1945 (No. 18 of 1945) [1946-01-06]
# Annual Volume of the Laws of the Gold Coast:
# Containing All Legislation Enacted During Year 1945, p 69
# https://books.google.com/books?id=9as-AQAAIAAJ&pg=PA69
# This Ordinance abolished DST.
#
# Time Determination (Amendment) Ordinance, 1950 (No. 26 of 1950) [1950-07-22]
# Annual Volume of the Laws of the Gold Coast:
# Containing All Legislation Enacted During Year 1950, p 35
# https://books.google.com/books?id=e60-AQAAIAAJ&pg=PA35
# This Ordinance restored DST but with thirty minutes offset.
#
# Time Determination Ordinance (Cap. 264)
# The Laws of the Gold Coast, Vol. V (1954), p 380
# https://books.google.com/books?id=Mqc-AQAAIAAJ&pg=PA380
# Revised edition of the Time Determination Ordinance.
#
# Time Determination (Amendment) Ordinance, 1956 (No. 21 of 1956) [1956-08-29]
# Annual Volume of the Ordinances of the Gold Coast Enacted During the
# Year 1956, p 83
# https://books.google.com/books?id=VLE-AQAAIAAJ&pg=PA83
# This Ordinance abolished DST.
# Rule NAME FROM TO - IN ON AT SAVE LETTER/S
Rule Ghana 1919 only - Nov 24 0:00 0:20 +0020
Rule Ghana 1920 1942 - Jan 1 2:00 0 GMT
Rule Ghana 1920 1939 - Sep 1 2:00 0:20 +0020
Rule Ghana 1940 1941 - May 1 2:00 0:20 +0020
Rule Ghana 1950 1955 - Sep 1 2:00 0:30 +0030
Rule Ghana 1951 1956 - Jan 1 2:00 0 GMT
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Africa/Accra -0:00:52 - LMT 1915 Nov 2
0:00 Ghana %s 1942 Feb 8
0:30 - +0030 1946 Jan 6
0:00 Ghana %s
# Guinea
# See Africa/Abidjan.
@ -533,15 +436,6 @@ Zone Africa/Nairobi 2:27:16 - LMT 1908 May
2:30 - +0230 1936 Dec 31 24:00
2:45 - +0245 1942 Jul 31 24:00
3:00 - EAT
Link Africa/Nairobi Africa/Addis_Ababa # Ethiopia
Link Africa/Nairobi Africa/Asmara # Eritrea
Link Africa/Nairobi Africa/Dar_es_Salaam # Tanzania
Link Africa/Nairobi Africa/Djibouti
Link Africa/Nairobi Africa/Kampala # Uganda
Link Africa/Nairobi Africa/Mogadishu # Somalia
Link Africa/Nairobi Indian/Antananarivo # Madagascar
Link Africa/Nairobi Indian/Comoro
Link Africa/Nairobi Indian/Mayotte
# Lesotho
# See Africa/Johannesburg.
@ -732,7 +626,7 @@ Zone Indian/Mauritius 3:50:00 - LMT 1907 # Port Louis
# See Africa/Nairobi.
# Morocco
# See the 'europe' file for Spanish Morocco (Africa/Ceuta).
# See Africa/Ceuta for Spanish Morocco.
# From Alex Krivenyshev (2008-05-09):
# Here is an article that Morocco plan to introduce Daylight Saving Time between
@ -1228,13 +1122,6 @@ Zone Africa/El_Aaiun -0:52:48 - LMT 1934 Jan # El Aaiún
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Africa/Maputo 2:10:20 - LMT 1903 Mar
2:00 - CAT
Link Africa/Maputo Africa/Blantyre # Malawi
Link Africa/Maputo Africa/Bujumbura # Burundi
Link Africa/Maputo Africa/Gaborone # Botswana
Link Africa/Maputo Africa/Harare # Zimbabwe
Link Africa/Maputo Africa/Kigali # Rwanda
Link Africa/Maputo Africa/Lubumbashi # E Dem. Rep. of Congo
Link Africa/Maputo Africa/Lusaka # Zambia
# Namibia
@ -1382,23 +1269,12 @@ Zone Africa/Lagos 0:13:35 - LMT 1905 Jul 1
0:13:35 - LMT 1914 Jan 1
0:30 - +0030 1919 Sep 1
1:00 - WAT
Link Africa/Lagos Africa/Bangui # Central African Republic
Link Africa/Lagos Africa/Brazzaville # Rep. of the Congo
Link Africa/Lagos Africa/Douala # Cameroon
Link Africa/Lagos Africa/Kinshasa # Dem. Rep. of the Congo (west)
Link Africa/Lagos Africa/Libreville # Gabon
Link Africa/Lagos Africa/Luanda # Angola
Link Africa/Lagos Africa/Malabo # Equatorial Guinea
Link Africa/Lagos Africa/Niamey # Niger
Link Africa/Lagos Africa/Porto-Novo # Benin
# Réunion
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Indian/Reunion 3:41:52 - LMT 1911 Jun # Saint-Denis
4:00 - +04
#
# Crozet Islands also observes Réunion time; see the 'antarctica' file.
#
# Scattered Islands (Îles Éparses) administered from Réunion are as follows.
# The following information about them is taken from
# Îles Éparses (<http://www.outre-mer.gouv.fr/domtom/ile.htm>, 1997-07-22,
@ -1490,8 +1366,6 @@ Rule SA 1943 1944 - Mar Sun>=15 2:00 0 -
Zone Africa/Johannesburg 1:52:00 - LMT 1892 Feb 8
1:30 - SAST 1903 Mar
2:00 SA SAST
Link Africa/Johannesburg Africa/Maseru # Lesotho
Link Africa/Johannesburg Africa/Mbabane # Eswatini
#
# Marion and Prince Edward Is
# scientific station since 1947
@ -1527,12 +1401,13 @@ Zone Africa/Khartoum 2:10:08 - LMT 1931
3:00 - EAT 2017 Nov 1
2:00 - CAT
# South Sudan
# From Steffen Thorsen (2021-01-18):
# "South Sudan will change its time zone by setting the clock back 1
# hour on February 1, 2021...."
# from https://eyeradio.org/south-sudan-adopts-new-time-zone-makuei/
# South Sudan
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Africa/Juba 2:06:28 - LMT 1931
2:00 Sudan CA%sT 2000 Jan 15 12:00
@ -1637,7 +1512,7 @@ Rule Tunisia 2005 only - Sep 30 1:00s 0 -
Rule Tunisia 2006 2008 - Mar lastSun 2:00s 1:00 S
Rule Tunisia 2006 2008 - Oct lastSun 2:00s 0 -
# See Europe/Paris for PMT-related transitions.
# See Europe/Paris commentary for PMT-related transitions.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Africa/Tunis 0:40:44 - LMT 1881 May 12
0:09:21 - PMT 1911 Mar 11 # Paris Mean Time

29
contrib/tzdata/antarctica
View file

@ -148,7 +148,7 @@ Zone Antarctica/Mawson 0 - -00 1954 Feb 13
#
# Alfred Faure, Possession Island, Crozet Islands, -462551+0515152, since 1964;
# sealing & whaling stations operated variously 1802/1911+;
# see Indian/Reunion.
# see Asia/Dubai.
#
# Martin-de-Viviès, Amsterdam Island, -374105+0773155, since 1950
# Port-aux-Français, Kerguelen Islands, -492110+0701303, since 1951;
@ -162,17 +162,7 @@ Zone Indian/Kerguelen 0 - -00 1950 # Port-aux-Français
5:00 - +05
#
# year-round base in the main continent
# Dumont d'Urville, Île des Pétrels, -6640+14001, since 1956-11
# <https://en.wikipedia.org/wiki/Dumont_d'Urville_Station> (2005-12-05)
#
# Another base at Port-Martin, 50km east, began operation in 1947.
# It was destroyed by fire on 1952-01-14.
#
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Antarctica/DumontDUrville 0 - -00 1947
10:00 - +10 1952 Jan 14
0 - -00 1956 Nov
10:00 - +10
# Dumont d'Urville - see Pacific/Port_Moresby.
# France & Italy - year-round base
# Concordia, -750600+1232000, since 2005
@ -188,20 +178,7 @@ Zone Antarctica/DumontDUrville 0 - -00 1947
# Zuchelli, Terra Nova Bay, -744140+1640647, since 1986
# Japan - year-round bases
# Syowa (also known as Showa), -690022+0393524, since 1957
#
# From Hideyuki Suzuki (1999-02-06):
# In all Japanese stations, +0300 is used as the standard time.
#
# Syowa station, which is the first antarctic station of Japan,
# was established on 1957-01-29. Since Syowa station is still the main
# station of Japan, it's appropriate for the principal location.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Antarctica/Syowa 0 - -00 1957 Jan 29
3:00 - +03
# See:
# NIPR Antarctic Research Activities (1999-08-17)
# http://www.nipr.ac.jp/english/ara01.html
# See Asia/Riyadh.
# S Korea - year-round base
# Jang Bogo, Terra Nova Bay, -743700+1641205 since 2014

34
contrib/tzdata/asia
View file

@ -34,9 +34,6 @@
# Byalokoz EL. New Counting of Time in Russia since July 1, 1919.
# (See the 'europe' file for a fuller citation.)
#
# A reliable and entertaining source about time zones is
# Derek Howse, Greenwich time and longitude, Philip Wilson Publishers (1997).
#
# The following alphabetic abbreviations appear in these tables
# (corrections are welcome):
# std dst
@ -1176,10 +1173,9 @@ Zone Asia/Famagusta 2:15:48 - LMT 1921 Nov 14
2:00 EUAsia EE%sT 2016 Sep 8
3:00 - +03 2017 Oct 29 1:00u
2:00 EUAsia EE%sT
# Classically, Cyprus belongs to Asia; e.g. see Herodotus, Histories, I.72.
# However, for various reasons many users expect to find it under Europe.
Link Asia/Nicosia Europe/Nicosia
# See the 'backward' file for the Europe/Nicosia link.
# Georgia
# From Paul Eggert (1994-11-19):
@ -2234,6 +2230,14 @@ Zone Asia/Tokyo 9:18:59 - LMT 1887 Dec 31 15:00u
# From Paul Eggert (2013-12-11):
# As Steffen suggested, consider the past 21-month experiment to be DST.
# From Steffen Thorsen (2021-09-24):
# The Jordanian Government announced yesterday that they will start DST
# in February instead of March:
# https://petra.gov.jo/Include/InnerPage.jsp?ID=37683&lang=en&name=en_news (English)
# https://petra.gov.jo/Include/InnerPage.jsp?ID=189969&lang=ar&name=news (Arabic)
# From the Arabic version, it seems to say it would be at midnight
# (assume 24:00) on the last Thursday in February, starting from 2022.
# Rule NAME FROM TO - IN ON AT SAVE LETTER/S
Rule Jordan 1973 only - Jun 6 0:00 1:00 S
Rule Jordan 1973 1975 - Oct 1 0:00 0 -
@ -2264,8 +2268,9 @@ Rule Jordan 2004 only - Oct 15 0:00s 0 -
Rule Jordan 2005 only - Sep lastFri 0:00s 0 -
Rule Jordan 2006 2011 - Oct lastFri 0:00s 0 -
Rule Jordan 2013 only - Dec 20 0:00 0 -
Rule Jordan 2014 max - Mar lastThu 24:00 1:00 S
Rule Jordan 2014 2021 - Mar lastThu 24:00 1:00 S
Rule Jordan 2014 max - Oct lastFri 0:00s 0 -
Rule Jordan 2022 max - Feb lastThu 24:00 1:00 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Amman 2:23:44 - LMT 1931
2:00 Jordan EE%sT
@ -2740,7 +2745,8 @@ Rule NBorneo 1935 1941 - Dec 14 0:00 0 -
#
# peninsular Malaysia
# taken from Mok Ly Yng (2003-10-30)
# http://www.math.nus.edu.sg/aslaksen/teaching/timezone.html
# https://web.archive.org/web/20190822231045/http://www.math.nus.edu.sg/~mathelmr/teaching/timezone.html
# This agrees with Singapore since 1905-06-01.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Kuala_Lumpur 6:46:46 - LMT 1901 Jan 1
6:55:25 - SMT 1905 Jun 1 # Singapore M.T.
@ -3500,6 +3506,12 @@ Zone Asia/Hebron 2:20:23 - LMT 1900 Oct
# influence of the sources. There is no current abbreviation for DST,
# so use "PDT", the usual American style.
# From P Chan (2021-05-10):
# Here's a fairly comprehensive article in Japanese:
# https://wiki.suikawiki.org/n/Philippine%20Time
# From Paul Eggert (2021-05-10):
# The info in the Japanese table has not been absorbed (yet) below.
# Rule NAME FROM TO - IN ON AT SAVE LETTER/S
Rule Phil 1936 only - Nov 1 0:00 1:00 D
Rule Phil 1937 only - Feb 1 0:00 0 S
@ -3519,7 +3531,6 @@ Zone Asia/Manila -15:56:00 - LMT 1844 Dec 31
Zone Asia/Qatar 3:26:08 - LMT 1920 # Al Dawhah / Doha
4:00 - +04 1972 Jun
3:00 - +03
Link Asia/Qatar Asia/Bahrain
# Saudi Arabia
#
@ -3566,12 +3577,10 @@ Link Asia/Qatar Asia/Bahrain
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Riyadh 3:06:52 - LMT 1947 Mar 14
3:00 - +03
Link Asia/Riyadh Asia/Aden # Yemen
Link Asia/Riyadh Asia/Kuwait
# Singapore
# taken from Mok Ly Yng (2003-10-30)
# http://www.math.nus.edu.sg/aslaksen/teaching/timezone.html
# https://web.archive.org/web/20190822231045/http://www.math.nus.edu.sg/~mathelmr/teaching/timezone.html
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Singapore 6:55:25 - LMT 1901 Jan 1
6:55:25 - SMT 1905 Jun 1 # Singapore M.T.
@ -3824,8 +3833,6 @@ Zone Asia/Dushanbe 4:35:12 - LMT 1924 May 2
Zone Asia/Bangkok 6:42:04 - LMT 1880
6:42:04 - BMT 1920 Apr # Bangkok Mean Time
7:00 - +07
Link Asia/Bangkok Asia/Phnom_Penh # Cambodia
Link Asia/Bangkok Asia/Vientiane # Laos
# Turkmenistan
# From Shanks & Pottenger.
@ -3840,7 +3847,6 @@ Zone Asia/Ashgabat 3:53:32 - LMT 1924 May 2 # or Ashkhabad
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Asia/Dubai 3:41:12 - LMT 1920
4:00 - +04
Link Asia/Dubai Asia/Muscat # Oman
# Uzbekistan
# Byalokoz 1919 says Uzbekistan was 4:27:53.

120
contrib/tzdata/australasia
View file

@ -458,13 +458,12 @@ Zone Pacific/Guam -14:21:00 - LMT 1844 Dec 31
9:00 - +09 1944 Jul 31
10:00 Guam G%sT 2000 Dec 23
10:00 - ChST # Chamorro Standard Time
Link Pacific/Guam Pacific/Saipan # N Mariana Is
# Kiribati
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Tarawa 11:32:04 - LMT 1901 # Bairiki
12:00 - +12
Zone Pacific/Enderbury -11:24:20 - LMT 1901
Zone Pacific/Kanton 0 - -00 1937 Aug 31
-12:00 - -12 1979 Oct
-11:00 - -11 1994 Dec 31
13:00 - +13
@ -584,8 +583,6 @@ Zone Pacific/Chatham 12:13:48 - LMT 1868 Nov 2
12:15 - +1215 1946 Jan 1
12:45 Chatham +1245/+1345
Link Pacific/Auckland Antarctica/McMurdo
# Auckland Is
# uninhabited; Māori and Moriori, colonial settlers, pastoralists, sealers,
# and scientific personnel have wintered
@ -597,13 +594,46 @@ Link Pacific/Auckland Antarctica/McMurdo
# was probably like Pacific/Auckland
# Cook Is
# From Shanks & Pottenger:
#
# From Alexander Krivenyshev (2021-03-24):
# In 1899 the Cook Islands celebrated Christmas twice to correct the calendar.
# According to the old books, missionaries were unaware of
# the International Date line, when they came from Sydney.
# Thus the Cook Islands were one day ahead....
# http://nzetc.victoria.ac.nz/tm/scholarly/tei-KloDisc-t1-body-d18.html
# ... Appendix to the Journals of the House of Representatives, 1900
# https://atojs.natlib.govt.nz/cgi-bin/atojs?a=d&d=AJHR1900-I.2.1.2.3
# (page 20)
#
# From Michael Deckers (2021-03-24):
# ... in the Cook Island Act of 1915-10-11, online at
# http://www.paclii.org/ck/legis/ck-nz_act/cia1915132/
# "651. The hour of the day shall in each of the islands included in the
# Cook Islands be determined in accordance with the meridian of that island."
# so that local (mean?) time was still used in Rarotonga (and Niue) in 1915.
# This was changed in the Cook Island Amendment Act of 1952-10-16 ...
# http://www.paclii.org/ck/legis/ck-nz_act/ciaa1952212/
# "651 (1) The hour of the day in each of the islands included in the Cook
# Islands, other than Niue, shall be determined as if each island were
# situated on the meridian one hundred and fifty-seven degrees thirty minutes
# West of Greenwich. (2) The hour of the day in the Island of Niue shall be
# determined as if that island were situated on the meridian one hundred and
# seventy degrees West of Greenwich."
# This act does not state when it takes effect, so one has to assume it
# applies since 1952-10-16. But there is the possibility that the act just
# legalized prior existing practice, as we had seen with the Guernsey law of
# 1913-06-18 for the switch in 1909-04-19.
#
# From Paul Eggert (2021-03-24):
# Transitions after 1952 are from Shanks & Pottenger.
#
# Rule NAME FROM TO - IN ON AT SAVE LETTER/S
Rule Cook 1978 only - Nov 12 0:00 0:30 -
Rule Cook 1979 1991 - Mar Sun>=1 0:00 0 -
Rule Cook 1979 1990 - Oct lastSun 0:00 0:30 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Rarotonga -10:39:04 - LMT 1901 # Avarua
Zone Pacific/Rarotonga 13:20:56 - LMT 1899 Dec 26 # Avarua
-10:39:04 - LMT 1952 Oct 16
-10:30 - -1030 1978 Nov 12
-10:00 Cook -10/-0930
@ -611,10 +641,18 @@ Zone Pacific/Rarotonga -10:39:04 - LMT 1901 # Avarua
# Niue
# See Pacific/Raratonga comments for 1952 transition.
#
# From Tim Parenti (2021-09-13):
# Consecutive contemporaneous editions of The Air Almanac listed -11:20 for
# Niue as of Apr 1964 but -11 as of Aug 1964:
# Apr 1964: https://books.google.com/books?id=_1So677Y5vUC&pg=SL1-PA23
# Aug 1964: https://books.google.com/books?id=MbJloqd-zyUC&pg=SL1-PA23
# Without greater specificity, guess 1964-07-01 for this transition.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Niue -11:19:40 - LMT 1901 # Alofi
-11:20 - -1120 1951
-11:30 - -1130 1978 Oct 1
Zone Pacific/Niue -11:19:40 - LMT 1952 Oct 16 # Alofi
-11:20 - -1120 1964 Jul
-11:00 - -11
# Norfolk
@ -673,7 +711,6 @@ Zone Pacific/Pitcairn -8:40:20 - LMT 1901 # Adamstown
Zone Pacific/Pago_Pago 12:37:12 - LMT 1892 Jul 5
-11:22:48 - LMT 1911
-11:00 - SST # S=Samoa
Link Pacific/Pago_Pago Pacific/Midway # in US minor outlying islands
# Samoa (formerly and also known as Western Samoa)
@ -742,13 +779,17 @@ Link Pacific/Pago_Pago Pacific/Midway # in US minor outlying islands
# From Paul Eggert (2014-07-08):
# That web page currently lists transitions for 2012/3 and 2013/4.
# Assume the pattern instituted in 2012 will continue indefinitely.
#
# From Geoffrey D. Bennett (2021-09-20):
# https://www.mcil.gov.ws/storage/2021/09/MCIL-Scan_20210920_120553.pdf
# DST has been cancelled for this year.
# Rule NAME FROM TO - IN ON AT SAVE LETTER/S
Rule WS 2010 only - Sep lastSun 0:00 1 -
Rule WS 2011 only - Apr Sat>=1 4:00 0 -
Rule WS 2011 only - Sep lastSat 3:00 1 -
Rule WS 2012 max - Apr Sun>=1 4:00 0 -
Rule WS 2012 max - Sep lastSun 3:00 1 -
Rule WS 2012 2021 - Apr Sun>=1 4:00 0 -
Rule WS 2012 2020 - Sep lastSun 3:00 1 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Apia 12:33:04 - LMT 1892 Jul 5
-11:26:56 - LMT 1911
@ -795,8 +836,8 @@ Rule Tonga 2001 2002 - Jan lastSun 2:00 0 -
Rule Tonga 2016 only - Nov Sun>=1 2:00 1:00 -
Rule Tonga 2017 only - Jan Sun>=15 3:00 0 -
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Pacific/Tongatapu 12:19:20 - LMT 1901
12:20 - +1220 1941
Zone Pacific/Tongatapu 12:19:12 - LMT 1945 Sep 10
12:20 - +1220 1961
13:00 - +13 1999
13:00 Tonga +13/+14
@ -1738,6 +1779,23 @@ Zone Pacific/Wallis 12:15:20 - LMT 1901
# One source for this is page 202 of: Bartky IR. One Time Fits All:
# The Campaigns for Global Uniformity (2007).
# Kanton
# From Paul Eggert (2021-05-27):
# Kiribati's +13 timezone is represented by Kanton, its only populated
# island. (It was formerly spelled "Canton", but Gilbertese lacks "C".)
# Kanton was settled on 1937-08-31 by two British radio operators
# <https://history.state.gov/historicaldocuments/frus1937v02/d94>;
# Americans came the next year and built an airfield, partly to
# establish airline service and perhaps partly anticipating the
# next war. Aside from the war, the airfield was used by commercial
# airlines until long-range jets became standard; although currently
# for emergency use only, China says it is considering rebuilding the
# airfield for high-end niche tourism. Kanton has about two dozen
# people, caretakers who rotate in from the rest of Kiribati in 2-5
# year shifts, and who use some of the leftover structures
# <http://pipa.neaq.org/2012/06/images-of-kanton-island.html>.
# Kwajalein
# From an AP article (1993-08-22):
@ -2021,6 +2079,17 @@ Zone Pacific/Wallis 12:15:20 - LMT 1901
# Tonga
# From Paul Eggert (2021-03-04):
# In 1943 "The standard time kept is 12 hrs. 19 min. 12 sec. fast
# on Greenwich mean time." according to the Admiralty's Hydrographic
# Dept., Pacific Islands Pilot, Vol. II, 7th ed., 1943, p 360.
# From Michael Deckers (2021-03-03):
# [Ian R Bartky: "One Time Fits All: The Campaigns for Global Uniformity".
# Stanford University Press. 2007. p. 255]:
# On 10 September 1945 Tonga adopted a standard time 12 hours,
# 20 minutes in advance of Greenwich.
# From Paul Eggert (1996-01-22):
# Today's _Wall Street Journal_ (p 1) reports that "Tonga has been plotting
# to sneak ahead of [New Zealanders] by introducing daylight-saving time."
@ -2049,9 +2118,26 @@ Zone Pacific/Wallis 12:15:20 - LMT 1901
# The Crown Prince, presented an unanswerable argument: "Remember that
# on the World Day of Prayer, you would be the first people on Earth
# to say your prayers in the morning."
# From Paul Eggert (2006-03-22):
# Shanks & Pottenger say the transition was on 1968-10-01; go with Mundell.
#
# From Tim Parenti (2021-09-13), per Paul Eggert (2006-03-22) and Michael
# Deckers (2021-03-03):
# Mundell places the transition from +12:20 to +13 in 1941, while Shanks &
# Pottenger say the transition was on 1968-10-01.
#
# The Air Almanac published contemporaneous tables of standard times,
# which listed +12:20 as of Nov 1960 and +13 as of Mar 1961:
# Nov 1960: https://books.google.com/books?id=bVgtWM6kPZUC&pg=SL1-PA19
# Mar 1961: https://books.google.com/books?id=W2nItAul4g0C&pg=SL1-PA19
# (Thanks to P Chan for pointing us toward these sources.)
# This agrees with Bartky, who writes that "since 1961 [Tonga's] official time
# has been thirteen hours in advance of Greenwich time" (p. 202) and further
# writes in an endnote that this was because "the legislation was amended" on
# 1960-10-19. (p. 255)
#
# Without greater specificity, presume that Bartky and the Air Almanac point to
# a 1961-01-01 transition, as Tāufaʻāhau Tupou IV was still Crown Prince in
# 1961 and this still jives with the gist of Mundell's telling, and go with
# this over Shanks & Pottenger.
# From Eric Ulevik (1999-05-03):
# Tonga's director of tourism, who is also secretary of the National Millennium

102
contrib/tzdata/backward
View file

@ -3,50 +3,121 @@
# This file is in the public domain, so clarified as of
# 2009-05-17 by Arthur David Olson.
# This file provides links between current names for timezones
# and their old names. Many names changed in late 1993.
# This file provides links from old or merged timezone names to current ones.
# Many names changed in late 1993, and many merged names moved here
# in the period from 2013 through 2021. Several of these names are
# also present in the file 'backzone', which has data important only
# for pre-1970 timestamps and so is out of scope for tzdb proper.
# Link TARGET LINK-NAME
Link Africa/Abidjan Africa/Accra
Link Africa/Nairobi Africa/Addis_Ababa
Link Africa/Nairobi Africa/Asmara
Link Africa/Nairobi Africa/Asmera
Link Africa/Abidjan Africa/Bamako
Link Africa/Lagos Africa/Bangui
Link Africa/Abidjan Africa/Banjul
Link Africa/Maputo Africa/Blantyre
Link Africa/Lagos Africa/Brazzaville
Link Africa/Maputo Africa/Bujumbura
Link Africa/Abidjan Africa/Conakry
Link Africa/Abidjan Africa/Dakar
Link Africa/Nairobi Africa/Dar_es_Salaam
Link Africa/Nairobi Africa/Djibouti
Link Africa/Lagos Africa/Douala
Link Africa/Abidjan Africa/Freetown
Link Africa/Maputo Africa/Gaborone
Link Africa/Maputo Africa/Harare
Link Africa/Nairobi Africa/Kampala
Link Africa/Maputo Africa/Kigali
Link Africa/Lagos Africa/Kinshasa
Link Africa/Lagos Africa/Libreville
Link Africa/Abidjan Africa/Lome
Link Africa/Lagos Africa/Luanda
Link Africa/Maputo Africa/Lubumbashi
Link Africa/Maputo Africa/Lusaka
Link Africa/Lagos Africa/Malabo
Link Africa/Johannesburg Africa/Maseru
Link Africa/Johannesburg Africa/Mbabane
Link Africa/Nairobi Africa/Mogadishu
Link Africa/Lagos Africa/Niamey
Link Africa/Abidjan Africa/Nouakchott
Link Africa/Abidjan Africa/Ouagadougou
Link Africa/Lagos Africa/Porto-Novo
Link Africa/Abidjan Africa/Timbuktu
Link America/Puerto_Rico America/Anguilla
Link America/Puerto_Rico America/Antigua
Link America/Argentina/Catamarca America/Argentina/ComodRivadavia
Link America/Puerto_Rico America/Aruba
Link America/Panama America/Atikokan
Link America/Adak America/Atka
Link America/Puerto_Rico America/Blanc-Sablon
Link America/Argentina/Buenos_Aires America/Buenos_Aires
Link America/Argentina/Catamarca America/Catamarca
Link America/Atikokan America/Coral_Harbour
Link America/Panama America/Cayman
Link America/Panama America/Coral_Harbour
Link America/Argentina/Cordoba America/Cordoba
Link America/Phoenix America/Creston
Link America/Puerto_Rico America/Curacao
Link America/Puerto_Rico America/Dominica
Link America/Tijuana America/Ensenada
Link America/Indiana/Indianapolis America/Fort_Wayne
Link America/Nuuk America/Godthab
Link America/Puerto_Rico America/Grenada
Link America/Puerto_Rico America/Guadeloupe
Link America/Indiana/Indianapolis America/Indianapolis
Link America/Argentina/Jujuy America/Jujuy
Link America/Indiana/Knox America/Knox_IN
Link America/Puerto_Rico America/Kralendijk
Link America/Kentucky/Louisville America/Louisville
Link America/Puerto_Rico America/Lower_Princes
Link America/Puerto_Rico America/Marigot
Link America/Argentina/Mendoza America/Mendoza
Link America/Toronto America/Montreal
Link America/Puerto_Rico America/Montserrat
Link America/Toronto America/Nassau
Link America/Puerto_Rico America/Port_of_Spain
Link America/Rio_Branco America/Porto_Acre
Link America/Argentina/Cordoba America/Rosario
Link America/Tijuana America/Santa_Isabel
Link America/Denver America/Shiprock
Link America/Port_of_Spain America/Virgin
Link America/Puerto_Rico America/St_Barthelemy
Link America/Puerto_Rico America/St_Kitts
Link America/Puerto_Rico America/St_Lucia
Link America/Puerto_Rico America/St_Thomas
Link America/Puerto_Rico America/St_Vincent
Link America/Puerto_Rico America/Tortola
Link America/Puerto_Rico America/Virgin
Link Pacific/Port_Moresby Antarctica/DumontDUrville
Link Pacific/Auckland Antarctica/McMurdo
Link Pacific/Auckland Antarctica/South_Pole
Link Asia/Riyadh Antarctica/Syowa
Link Europe/Oslo Arctic/Longyearbyen
Link Asia/Riyadh Asia/Aden
Link Asia/Ashgabat Asia/Ashkhabad
Link Asia/Qatar Asia/Bahrain
Link Asia/Kolkata Asia/Calcutta
Link Asia/Shanghai Asia/Chongqing
Link Asia/Shanghai Asia/Chungking
Link Asia/Dhaka Asia/Dacca
Link Asia/Shanghai Asia/Harbin
Link Europe/Istanbul Asia/Istanbul
Link Asia/Urumqi Asia/Kashgar
Link Asia/Kathmandu Asia/Katmandu
Link Asia/Riyadh Asia/Kuwait
Link Asia/Macau Asia/Macao
Link Asia/Dubai Asia/Muscat
Link Asia/Bangkok Asia/Phnom_Penh
Link Asia/Yangon Asia/Rangoon
Link Asia/Ho_Chi_Minh Asia/Saigon
Link Asia/Jerusalem Asia/Tel_Aviv
Link Asia/Thimphu Asia/Thimbu
Link Asia/Makassar Asia/Ujung_Pandang
Link Asia/Ulaanbaatar Asia/Ulan_Bator
Link Asia/Bangkok Asia/Vientiane
Link Atlantic/Faroe Atlantic/Faeroe
Link Europe/Oslo Atlantic/Jan_Mayen
Link Europe/Berlin Atlantic/Jan_Mayen
Link Africa/Abidjan Atlantic/St_Helena
Link Australia/Sydney Australia/ACT
Link Australia/Sydney Australia/Canberra
Link Australia/Hobart Australia/Currie
@ -81,7 +152,22 @@ Link Africa/Cairo Egypt
Link Europe/Dublin Eire
Link Etc/UTC Etc/UCT
Link Europe/London Europe/Belfast
Link Europe/Prague Europe/Bratislava
Link Europe/Zurich Europe/Busingen
Link Europe/London Europe/Guernsey
Link Europe/London Europe/Isle_of_Man
Link Europe/London Europe/Jersey
Link Europe/Belgrade Europe/Ljubljana
Link Europe/Helsinki Europe/Mariehamn
Link Asia/Nicosia Europe/Nicosia
Link Europe/Belgrade Europe/Podgorica
Link Europe/Rome Europe/San_Marino
Link Europe/Belgrade Europe/Sarajevo
Link Europe/Belgrade Europe/Skopje
Link Europe/Chisinau Europe/Tiraspol
Link Europe/Zurich Europe/Vaduz
Link Europe/Rome Europe/Vatican
Link Europe/Belgrade Europe/Zagreb
Link Europe/London GB
Link Europe/London GB-Eire
Link Etc/GMT GMT+0
@ -90,6 +176,9 @@ Link Etc/GMT GMT0
Link Etc/GMT Greenwich
Link Asia/Hong_Kong Hongkong
Link Atlantic/Reykjavik Iceland
Link Africa/Nairobi Indian/Antananarivo
Link Africa/Nairobi Indian/Comoro
Link Africa/Nairobi Indian/Mayotte
Link Asia/Tehran Iran
Link Asia/Jerusalem Israel
Link America/Jamaica Jamaica
@ -103,8 +192,11 @@ Link Pacific/Auckland NZ
Link Pacific/Chatham NZ-CHAT
Link America/Denver Navajo
Link Asia/Shanghai PRC
Link Pacific/Kanton Pacific/Enderbury
Link Pacific/Honolulu Pacific/Johnston
Link Pacific/Pago_Pago Pacific/Midway
Link Pacific/Pohnpei Pacific/Ponape
Link Pacific/Guam Pacific/Saipan
Link Pacific/Pago_Pago Pacific/Samoa
Link Pacific/Chuuk Pacific/Truk
Link Pacific/Chuuk Pacific/Yap

426
contrib/tzdata/backzone
View file

@ -68,6 +68,91 @@
#
# As explained in the zic man page, the zone columns are:
# Zone NAME STDOFF RULES FORMAT [UNTIL]
# and the rule columns are:
# Rule NAME FROM TO - IN ON AT SAVE LETTER/S
# Ghana
# From P Chan (2020-11-20):
# Interpretation Amendment Ordinance, 1915 (No.24 of 1915) [1915-11-02]
# Ordinances of the Gold Coast, Ashanti, Northern Territories 1915, p 69-71
# https://books.google.com/books?id=ErA-AQAAIAAJ&pg=PA70
# This Ordinance added "'Time' shall mean Greenwich Mean Time" to the
# Interpretation Ordinance, 1876.
#
# Determination of the Time Ordinance, 1919 (No. 18 of 1919) [1919-11-24]
# Ordinances of the Gold Coast, Ashanti, Northern Territories 1919, p 75-76
# https://books.google.com/books?id=MbA-AQAAIAAJ&pg=PA75
# This Ordinance removed the previous definition of time and introduced DST.
#
# Time Determination Ordinance (Cap. 214)
# The Laws of the Gold Coast (including Togoland Under British Mandate)
# Vol. II (1937), p 2328
# https://books.google.com/books?id=Z7M-AQAAIAAJ&pg=PA2328
# Revised edition of the 1919 Ordinance.
#
# Time Determination (Amendment) Ordinance, 1940 (No. 9 of 1940) [1940-04-06]
# Annual Volume of the Laws of the Gold Coast:
# Containing All Legislation Enacted During Year 1940, p 22
# https://books.google.com/books?id=1ao-AQAAIAAJ&pg=PA22
# This Ordinance changed the forward transition from September to May.
#
# Defence (Time Determination Ordinance Amendment) Regulations, 1942
# (Regulations No. 6 of 1942) [1942-01-31, commenced on 1942-02-08]
# Annual Volume of the Laws of the Gold Coast:
# Containing All Legislation Enacted During Year 1942, p 48
# https://books.google.com/books?id=Das-AQAAIAAJ&pg=PA48
# These regulations advanced the [standard] time by thirty minutes.
#
# Defence (Time Determination Ordinance Amendment (No.2)) Regulations,
# 1942 (Regulations No. 28 of 1942) [1942-04-25]
# Annual Volume of the Laws of the Gold Coast:
# Containing All Legislation Enacted During Year 1942, p 87
# https://books.google.com/books?id=Das-AQAAIAAJ&pg=PA87
# These regulations abolished DST and changed the time to GMT+0:30.
#
# Defence (Revocation) (No.4) Regulations, 1945 (Regulations No. 45 of
# 1945) [1945-10-24, commenced on 1946-01-06]
# Annual Volume of the Laws of the Gold Coast:
# Containing All Legislation Enacted During Year 1945, p 256
# https://books.google.com/books?id=9as-AQAAIAAJ&pg=PA256
# These regulations revoked the previous two sets of Regulations.
#
# Time Determination (Amendment) Ordinance, 1945 (No. 18 of 1945) [1946-01-06]
# Annual Volume of the Laws of the Gold Coast:
# Containing All Legislation Enacted During Year 1945, p 69
# https://books.google.com/books?id=9as-AQAAIAAJ&pg=PA69
# This Ordinance abolished DST.
#
# Time Determination (Amendment) Ordinance, 1950 (No. 26 of 1950) [1950-07-22]
# Annual Volume of the Laws of the Gold Coast:
# Containing All Legislation Enacted During Year 1950, p 35
# https://books.google.com/books?id=e60-AQAAIAAJ&pg=PA35
# This Ordinance restored DST but with thirty minutes offset.
#
# Time Determination Ordinance (Cap. 264)
# The Laws of the Gold Coast, Vol. V (1954), p 380
# https://books.google.com/books?id=Mqc-AQAAIAAJ&pg=PA380
# Revised edition of the Time Determination Ordinance.
#
# Time Determination (Amendment) Ordinance, 1956 (No. 21 of 1956) [1956-08-29]
# Annual Volume of the Ordinances of the Gold Coast Enacted During the
# Year 1956, p 83
# https://books.google.com/books?id=VLE-AQAAIAAJ&pg=PA83
# This Ordinance abolished DST.
Rule Ghana 1919 only - Nov 24 0:00 0:20 +0020
Rule Ghana 1920 1942 - Jan 1 2:00 0 GMT
Rule Ghana 1920 1939 - Sep 1 2:00 0:20 +0020
Rule Ghana 1940 1941 - May 1 2:00 0:20 +0020
Rule Ghana 1950 1955 - Sep 1 2:00 0:30 +0030
Rule Ghana 1951 1956 - Jan 1 2:00 0 GMT
Zone Africa/Accra -0:00:52 - LMT 1915 Nov 2
0:00 Ghana %s 1942 Feb 8
0:30 - +0030 1946 Jan 6
0:00 Ghana %s
# Ethiopia
# From Paul Eggert (2014-07-31):
@ -101,14 +186,36 @@ Zone Africa/Bamako -0:32:00 - LMT 1912
Zone Africa/Bangui 1:14:20 - LMT 1912
1:00 - WAT
# Gambia
# The Gambia
# From P Chan (2020-12-09):
# Standard time of GMT-1 was adopted on 1933-04-01. On 1942-02-01, GMT was
# adopted as a war time measure. This was made permanent in 1946.
#
# Interpretation Ordinance, 1914 (No. 12 of 1914) [1914-09-29]
# Interpretation Ordinance, 1933 (No. 10 of 1933) [1933-03-31]
# Notice No. 5 of 1942, Colony of the Gambia Government Gazette, Vol. LIX,
# No.2, 1942-01-15, p 2
# Interpretation (Amendment) Ordinance, 1946 (No. 3 of 1946) [1946-07-15]
Zone Africa/Banjul -1:06:36 - LMT 1912
-1:06:36 - BMT 1935 # Banjul Mean Time
-1:00 - -01 1964
-1:06:36 - BMT 1933 Apr 1 # Banjul Mean Time
-1:00 - -01 1942 Feb 1 0:00
0:00 - GMT
# Malawi
Zone Africa/Blantyre 2:20:00 - LMT 1903 Mar
# From P Chan (2020-12-09):
# In 1911, Zomba mean time was adopted as the legal time of Nyasaland. In
# 1914, Zomba mean time switched from GMT+2:21:10 to GMT+2:21. On 1925-07-01,
# GMT+2 was adopted.
#
# Interpretation and General Clauses Ordinance, 1911 (No. 12 of 1911)
# [1911-07-24]
# Notice No. 124 of 1914, 1914-06-30, The Nyasaland Government Gazette, Vol.
# XXI, No. 8, 1914-06-30, p 122
# Interpretation and General Clauses (Amendment) Ordinance, 1925 (No. 3 of
# 1925) [1925-04-02]
Zone Africa/Blantyre 2:20:00 - LMT 1911 Jul 24
2:21:10 - ZMT 1914 Jun 30 # Zomba Mean Time
2:21 - ZMT 1925 Jul 1
2:00 - CAT
# Republic of the Congo
@ -145,19 +252,48 @@ Zone Africa/Djibouti 2:52:36 - LMT 1911 Jul
Zone Africa/Douala 0:38:48 - LMT 1912
1:00 - WAT
# Sierra Leone
# From Paul Eggert (2014-08-12):
# The following table is from Shanks & Pottenger, but it can't be right.
# Whitman gives Mar 31 - Aug 31 for 1931 on.
# The International Hydrographic Bulletin, 1932-33, p 63 says that
# Sierra Leone would advance its clocks by 20 minutes on 1933-10-01.
# Rule NAME FROM TO - IN ON AT SAVE LETTER/S
Rule SL 1935 1942 - Jun 1 0:00 0:40 -0020
Rule SL 1935 1942 - Oct 1 0:00 0 -01
Rule SL 1957 1962 - Jun 1 0:00 1:00 +01
Rule SL 1957 1962 - Sep 1 0:00 0 GMT
# From P Chan (2020-12-09):
# Standard time of GMT-1 was adopted on 1913-07-01. Twenty minutes of DST was
# introduce[d] in 1932 and was suspended in 1939. In 1941, GMT was adopted by
# Defence Regulations. This was made permanent in 1946.
#
# Government Notice No. 121 of 1913, 1913-06-06, Sierra Leone Royal Gazette,
# Vol. XLIV, No. 1384, 1913-06-14, p 347
# Alteration of Time Ordinance, 1932 (No. 34 of 1932) [1932-12-01]
# Alteration of Time (Amendment) Ordinance, 1938 (No. 25 of 1938) [1938-11-24]
# Defence Regulations (No. 9), 1939 (Regulations No. 9 of 1939), 1939-09-05
# Defence Regulations (No. 11), 1939 (Regulations No. 11 of 1939), 1939-09-27
# Defence (Amendment) (No. 17) Regulations, 1941 (Public Notice No. 157 of
# 1941), 1914-12-04
# Alteration of Time (Amendment) Ordinance, 1946 (No. 2 of 1946) [1946-02-07]
# From Tim Parenti (2021-03-02), per P Chan (2021-02-25):
# For Sierra Leone in 1957-1962, the standard time was defined in the
# Alteration of Time Ordinance, 1932 (as amended in 1946, renamed to Local Time
# Ordinance in 1960 and Local Time Act in 1961). It was unamended throughout
# that period. See references to "Time" in the Alphabetical Index of the
# Legislation in force on the 31st day of December,
# 1957: https://books.google.com/books?id=lvQ-AQAAIAAJ&pg=RA2-PA49
# 1958: https://books.google.com/books?id=4fQ-AQAAIAAJ&pg=RA2-PA50
# 1959: https://books.google.com/books?id=p_U-AQAAIAAJ&pg=RA2-PA55
# 1960: https://books.google.com/books?id=JPY-AQAAIAAJ&pg=RA3-PA37
# 1961: https://books.google.com/books?id=7vY-AQAAIAAJ&pg=RA3-PA41
# 1962: https://books.google.com/books?id=W_c-AQAAIAAJ&pg=RA3-PA44
# 1963: https://books.google.com/books?id=9vk-AQAAIAAJ&pg=RA1-PA47
#
# Although Shanks & Pottenger had DST from Jun 1 00:00 to Sep 1 00:00 in this
# period, many contemporaneous almanacs agree that it wasn't used:
# https://mm.icann.org/pipermail/tz/2021-February/029866.html
# Go with the above.
Rule SL 1932 only - Dec 1 0:00 0:20 -0040
Rule SL 1933 1938 - Mar 31 24:00 0 -01
Rule SL 1933 1939 - Aug 31 24:00 0:20 -0040
Rule SL 1939 only - May 31 24:00 0 -01
Zone Africa/Freetown -0:53:00 - LMT 1882
-0:53:00 - FMT 1913 Jun # Freetown Mean Time
-1:00 SL %s 1957
-0:53:00 - FMT 1913 Jul 1 # Freetown MT
-1:00 SL %s 1939 Sep 5
-1:00 - -01 1941 Dec 6 24:00
0:00 SL GMT/+01
# Botswana
@ -298,6 +434,85 @@ Zone America/Aruba -4:40:24 - LMT 1912 Feb 12 # Oranjestad
-4:30 - -0430 1965
-4:00 - AST
# Atikokan, Ontario
# From Paul Eggert (1997-10-17):
# Mark Brader writes that an article in the 1997-10-14 Toronto Star
# says that Atikokan, Ontario currently does not observe DST,
# but will vote on 11-10 whether to use EST/EDT.
# He also writes that the Ontario Time Act (1990, Chapter T.9)
# http://www.gov.on.ca/MBS/english/publications/statregs/conttext.html
# says that Ontario east of 90W uses EST/EDT, and west of 90W uses CST/CDT.
# Officially Atikokan is therefore on CST/CDT, and most likely this report
# concerns a non-official time observed as a matter of local practice.
#
# From Paul Eggert (2000-10-02):
# Matthews and Vincent (1998) write that Atikokan, Pickle Lake, and
# New Osnaburgh observe CST all year, that Big Trout Lake observes
# CST/CDT, and that Upsala and Shebandowan observe EST/EDT, all in
# violation of the official Ontario rules.
#
# From Paul Eggert (2006-07-09):
# Chris Walton (2006-07-06) mentioned an article by Stephanie MacLellan in the
# 2005-07-21 Chronicle-Journal, which said:
#
# The clocks in Atikokan stay set on standard time year-round.
# This means they spend about half the time on central time and
# the other half on eastern time.
#
# For the most part, the system works, Mayor Dennis Brown said.
#
# "The majority of businesses in Atikokan deal more with Eastern
# Canada, but there are some that deal with Western Canada," he
# said. "I don't see any changes happening here."
#
# Walton also writes "Supposedly Pickle Lake and Mishkeegogamang
# [New Osnaburgh] follow the same practice."
# From Garry McKinnon (2006-07-14) via Chris Walton:
# I chatted with a member of my board who has an outstanding memory
# and a long history in Atikokan (and in the telecom industry) and he
# can say for certain that Atikokan has been practicing the current
# time keeping since 1952, at least.
# From Paul Eggert (2006-07-17):
# Shanks & Pottenger say that Atikokan has agreed with Rainy River
# 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
# entry since our cutoff date of 1970, so we can move
# America/Coral_Harbour to the 'backward' file.
Zone America/Atikokan -6:06:28 - LMT 1895
-6:00 Canada C%sT 1940 Sep 29
-6:00 1:00 CDT 1942 Feb 9 2:00s
-6:00 Canada C%sT 1945 Sep 30 2:00
-5:00 - EST
# Quebec east of Natashquan
# From Paul Eggert (2021-05-09):
# H. David Matthews and Mary Vincent's map
# "It's about TIME", _Canadian Geographic_ (September-October 1998)
# http://www.canadiangeographic.ca/Magazine/SO98/alacarte.asp
# says that Quebec east of the -63 meridian is supposed to observe
# AST, but residents as far east as Natashquan use EST/EDT, and
# residents east of Natashquan use AST.
# The Quebec department of justice writes in
# "The situation in Minganie and Basse-Côte-Nord"
# https://www.justice.gouv.qc.ca/en/department/ministre/functions-and-responsabilities/legal-time-in-quebec/the-situation-in-minganie-and-basse-cote-nord/
# that the coastal strip from just east of Natashquan to Blanc-Sablon
# observes Atlantic standard time all year round.
# This common practice was codified into law as of 2007; see Legal Time Act,
# CQLR c T-5.1 <http://legisquebec.gouv.qc.ca/en/ShowDoc/cs/T-5.1>.
# For lack of better info, guess this practice began around 1970, contra to
# Shanks & Pottenger who have this region observing AST/ADT.
Zone America/Blanc-Sablon -3:48:28 - LMT 1884
-4:00 Canada A%sT 1970
-4:00 - AST
# Cayman Is
Zone America/Cayman -5:25:32 - LMT 1890 # Georgetown
-5:07:10 - KMT 1912 Feb # Kingston Mean Time
@ -318,6 +533,85 @@ Zone America/Coral_Harbour -5:32:40 - LMT 1884
-5:00 NT_YK E%sT 1946
-5:00 - EST
# From Chris Walton (2011-12-01):
# There are two areas within the Canadian province of British Columbia
# that do not currently observe daylight saving:
# a) The Creston Valley (includes the town of Creston and surrounding area)
# b) The eastern half of the Peace River Regional District
# (includes the cities of Dawson Creek and Fort St. John)
# Earlier this year I stumbled across a detailed article about the time
# keeping history of Creston; it was written by Tammy Hardwick who is the
# manager of the Creston & District Museum. The article was written in May 2009.
# http://www.ilovecreston.com/?p=articles&t=spec&ar=260
# According to the article, Creston has not changed its clocks since June 1918.
# i.e. Creston has been stuck on UT-7 for 93 years.
# Dawson Creek, on the other hand, changed its clocks as recently as April 1972.
# Unfortunately the exact date for the time change in June 1918 remains
# unknown and will be difficult to ascertain. I e-mailed Tammy a few months
# ago to ask if Sunday June 2 was a reasonable guess. She said it was just
# as plausible as any other date (in June). She also said that after writing
# the article she had discovered another time change in 1916; this is the
# subject of another article which she wrote in October 2010.
# http://www.creston.museum.bc.ca/index.php?module=comments&uop=view_comment&cm+id=56
# Here is a summary of the three clock change events in Creston's history:
# 1. 1884 or 1885: adoption of Mountain Standard Time (GMT-7)
# Exact date unknown
# 2. Oct 1916: switch to Pacific Standard Time (GMT-8)
# Exact date in October unknown; Sunday October 1 is a reasonable guess.
# 3. June 1918: switch to Pacific Daylight Time (GMT-7)
# Exact date in June unknown; Sunday June 2 is a reasonable guess.
# note 1:
# On Oct 27/1918 when daylight saving ended in the rest of Canada,
# Creston did not change its clocks.
# note 2:
# During WWII when the Federal Government legislated a mandatory clock change,
# Creston did not oblige.
# note 3:
# There is no guarantee that Creston will remain on Mountain Standard Time
# (UTC-7) forever.
# The subject was debated at least once this year by the town Council.
# http://www.bclocalnews.com/kootenay_rockies/crestonvalleyadvance/news/116760809.html
# During a period WWII, summer time (Daylight saying) was mandatory in Canada.
# In Creston, that was handled by shifting the area to PST (-8:00) then applying
# summer time to cause the offset to be -7:00, the same as it had been before
# the change. It can be argued that the timezone abbreviation during this
# period should be PDT rather than MST, but that doesn't seem important enough
# (to anyone) to further complicate the rules.
# The transition dates (and times) are guesses.
Zone America/Creston -7:46:04 - LMT 1884
-7:00 - MST 1916 Oct 1
-8:00 - PST 1918 Jun 2
-7:00 - MST
# Curaçao
# Milne gives 4:35:46.9 for Curaçao mean time; round to nearest.
#
# From Paul Eggert (2006-03-22):
# Shanks & Pottenger say that The Bottom and Philipsburg have been at
# -4:00 since standard time was introduced on 1912-03-02; and that
# Kralendijk and Rincon used Kralendijk Mean Time (-4:33:08) from
# 1912-02-02 to 1965-01-01. The former is dubious, since S&P also say
# Saba Island has been like Curaçao.
# This all predates our 1970 cutoff, though.
#
# By July 2007 Curaçao and St Maarten are planned to become
# associated states within the Netherlands, much like Aruba;
# Bonaire, Saba and St Eustatius would become directly part of the
# Netherlands as Kingdom Islands. This won't affect their time zones
# though, as far as we know.
#
Zone America/Curacao -4:35:47 - LMT 1912 Feb 12 # Willemstad
-4:30 - -0430 1965
-4:00 - AST
Link America/Curacao America/Kralendijk
Link America/Curacao America/Lower_Princes
# Dominica
Zone America/Dominica -4:05:36 - LMT 1911 Jul 1 0:01 # Roseau
-4:00 - AST
@ -340,6 +634,7 @@ Zone America/Grenada -4:07:00 - LMT 1911 Jul # St George's
Zone America/Guadeloupe -4:06:08 - LMT 1911 Jun 8 # Pointe-à-Pitre
-4:00 - AST
# Canada
#
# From Paul Eggert (2015-03-24):
@ -351,7 +646,6 @@ Zone America/Guadeloupe -4:06:08 - LMT 1911 Jun 8 # Pointe-à-Pitre
# Pottenger data. The post-1970 entries have been corrected, but the
# pre-1970 entries are unchecked and probably have errors.
#
# Rule NAME FROM TO - IN ON AT SAVE LETTER/S
Rule Mont 1917 only - Mar 25 2:00 1:00 D
Rule Mont 1917 only - Apr 24 0:00 0 S
Rule Mont 1919 only - Mar 31 2:30 1:00 D
@ -387,6 +681,48 @@ Zone America/Montreal -4:54:16 - LMT 1884
Zone America/Montserrat -4:08:52 - LMT 1911 Jul 1 0:01 # Cork Hill
-4:00 - AST
# The Bahamas
#
# For 1899 Milne gives -5:09:29.5; round that.
#
# From P Chan (2020-11-27, corrected on 2020-12-02):
# There were two periods of DST observed in 1942-1945: 1942-05-01
# midnight to 1944-12-31 midnight and 1945-02-01 to 1945-10-17 midnight.
# "midnight" should mean 24:00 from the context.
#
# War Time Order 1942 [1942-05-01] and War Time (No. 2) Order 1942 [1942-09-29]
# Appendix to the Statutes of 7 George VI. and the Year 1942. p 34, 43
# https://books.google.com/books?id=5rlNAQAAIAAJ&pg=RA3-PA34
# https://books.google.com/books?id=5rlNAQAAIAAJ&pg=RA3-PA43
#
# War Time Order 1943 [1943-03-31] and War Time Order 1944 [1943-12-29]
# Appendix to the Statutes of 8 George VI. and the Year 1943. p 9-10, 28-29
# https://books.google.com/books?id=5rlNAQAAIAAJ&pg=RA4-PA9
# https://books.google.com/books?id=5rlNAQAAIAAJ&pg=RA4-PA28
#
# War Time Order 1945 [1945-01-31] and the Order which revoke War Time Order
# 1945 [1945-10-16] Appendix to the Statutes of 9 George VI. and the Year
# 1945. p 160, 247-248
# https://books.google.com/books?id=5rlNAQAAIAAJ&pg=RA6-PA160
# https://books.google.com/books?id=5rlNAQAAIAAJ&pg=RA6-PA247
#
# From Sue Williams (2006-12-07):
# The Bahamas announced about a month ago that they plan to change their DST
# rules to sync with the U.S. starting in 2007....
# http://www.jonesbahamas.com/?c=45&a=10412
Rule Bahamas 1942 only - May 1 24:00 1:00 W
Rule Bahamas 1944 only - Dec 31 24:00 0 S
Rule Bahamas 1945 only - Feb 1 0:00 1:00 W
Rule Bahamas 1945 only - Aug 14 23:00u 1:00 P # Peace
Rule Bahamas 1945 only - Oct 17 24:00 0 S
Rule Bahamas 1964 1975 - Oct lastSun 2:00 0 S
Rule Bahamas 1964 1975 - Apr lastSun 2:00 1:00 D
Zone America/Nassau -5:09:30 - LMT 1912 Mar 2
-5:00 Bahamas E%sT 1976
-5:00 US E%sT
# United States
#
# From Paul Eggert (2018-03-18):
@ -411,6 +747,13 @@ Zone America/Montserrat -4:08:52 - LMT 1911 Jul 1 0:01 # Cork Hill
# https://cdnc.ucr.edu/cgi-bin/cdnc?a=d&d=DS19470110
# front page reports on end.
# Trinidad and Tobago
Zone America/Port_of_Spain -4:06:04 - LMT 1912 Mar 2
-4:00 - AST
Link America/Port_of_Spain America/Marigot
Link America/Port_of_Spain America/St_Barthelemy
Link America/Port_of_Spain America/Virgin
# Argentina
# This entry was intended for the following areas, but has been superseded by
# more detailed zones.
@ -434,7 +777,7 @@ Zone America/St_Lucia -4:04:00 - LMT 1890 # Castries
-4:04:00 - CMT 1912 # Castries Mean Time
-4:00 - AST
# Virgin Is
# US Virgin Is
Zone America/St_Thomas -4:19:44 - LMT 1911 Jul # Charlotte Amalie
-4:00 - AST
@ -447,11 +790,36 @@ Zone America/St_Vincent -4:04:56 - LMT 1890 # Kingstown
Zone America/Tortola -4:18:28 - LMT 1911 Jul # Road Town
-4:00 - AST
# Dumont d'Urville, Île des Pétrels, -6640+14001, since 1956-11
# <https://en.wikipedia.org/wiki/Dumont_d'Urville_Station> (2005-12-05)
#
# Another base at Port-Martin, 50km east, began operation in 1947.
# It was destroyed by fire on 1952-01-14.
#
Zone Antarctica/DumontDUrville 0 - -00 1947
10:00 - +10 1952 Jan 14
0 - -00 1956 Nov
10:00 - +10
# McMurdo, Ross Island, since 1955-12
Zone Antarctica/McMurdo 0 - -00 1956
12:00 NZ NZ%sT
Link Antarctica/McMurdo Antarctica/South_Pole
# Syowa, Antarctica
#
# From Hideyuki Suzuki (1999-02-06):
# In all Japanese stations, +0300 is used as the standard time.
#
# Syowa station, which is the first antarctic station of Japan,
# was established on 1957-01-29. Since Syowa station is still the main
# station of Japan, it's appropriate for the principal location.
Zone Antarctica/Syowa 0 - -00 1957 Jan 29
3:00 - +03
# See:
# NIPR Antarctic Research Activities (1999-08-17)
# http://www.nipr.ac.jp/english/ara01.html
# Yemen
# Milne says 2:59:54 was the meridian of the saluting battery at Aden,
# and that Yemen was at 1:55:56, the meridian of the Hagia Sophia.
@ -711,6 +1079,8 @@ Zone Europe/Skopje 1:25:44 - LMT 1884
1:00 - CET 1982 Nov 27
1:00 EU CE%sT
# Moldova / Transnistria
Zone Europe/Tiraspol 1:58:32 - LMT 1880
1:55 - CMT 1918 Feb 15 # Chisinau MT
@ -749,10 +1119,22 @@ Zone Indian/Comoro 2:53:04 - LMT 1911 Jul # Moroni, Gran Comoro
Zone Indian/Mayotte 3:00:56 - LMT 1911 Jul # Mamoutzou
3:00 - EAT
# US minor outlying islands
# Phoenix Islands, Kiribati
# From Paul Eggert (2021-05-27):
# 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.
Zone Pacific/Enderbury 0 - -00 1860
-11:24:20 - LMT 1885
0 - -00 1938 Mar 6
-12:00 - -12 1942 Feb 9
0 - -00
# Johnston
Zone Pacific/Johnston -10:00 - HST
# US minor outlying islands
# Midway
#
# From Mark Brader (2005-01-23):
# [Fallacies and Fantasies of Air Transport History, by R.E.G. Davies,
@ -775,3 +1157,7 @@ Zone Pacific/Saipan -14:17:00 - LMT 1844 Dec 31
9:00 - +09 1969 Oct
10:00 - +10 2000 Dec 23
10:00 - ChST # Chamorro Standard Time
# Local Variables:
# coding: utf-8
# End:

54
contrib/tzdata/checktab.awk
View file

@ -58,11 +58,12 @@ BEGIN {
zone_table, zone_NR >>"/dev/stderr"
status = 1
}
split($1, cca, /,/)
cc = cca[1]
ccs = input_ccs[zone_NR] = $1
coordinates = $2
tz = $3
comments = $4
comments = input_comments[zone_NR] = $4
split(ccs, cca, /,/)
cc = cca[1]
# Don't complain about a special case for Crimea in zone.tab.
# FIXME: zone.tab should be removed, since it is obsolete.
@ -77,12 +78,9 @@ BEGIN {
cc0 = cc
tz0 = tz
tztab[tz] = 1
tz2comments[tz] = comments
tz2NR[tz] = zone_NR
for (i in cca) {
cc = cca[i]
cctz = cc tz
cctztab[cctz] = 1
if (cc2name[cc]) {
cc_used[cc]++
} else {
@ -99,27 +97,27 @@ BEGIN {
}
}
for (cctz in cctztab) {
cc = substr (cctz, 1, 2)
tz = substr (cctz, 3)
if (1 < cc_used[cc]) {
comments_needed[tz] = cc
}
}
for (cctz in cctztab) {
cc = substr (cctz, 1, 2)
tz = substr (cctz, 3)
if (!comments_needed[tz] && tz2comments[tz]) {
for (i = 1; i <= zone_NR; i++) {
ccs = input_ccs[i]
if (!ccs) continue
comments = input_comments[i]
split(ccs, cca, /,/)
used_max = 0
for (j in cca) {
cc = cca[j]
if (used_max < cc_used[cc]) {
used_max = cc_used[cc]
}
}
if (used_max <= 1 && comments) {
printf "%s:%d: unnecessary comment '%s'\n", \
zone_table, tz2NR[tz], tz2comments[tz] \
>>"/dev/stderr"
tz2comments[tz] = 0
status = 1
} else if (comments_needed[tz] && !tz2comments[tz]) {
printf "%s:%d: missing comment for %s\n", \
zone_table, tz2NR[tz], comments_needed[tz] \
zone_table, i, comments \
>>"/dev/stderr"
status = 1
} else if (1 < cc_used[cc] && !comments) {
printf "%s:%d: missing comment for %s\n", \
zone_table, i, cc \
>>"/dev/stderr"
tz2comments[tz] = 1
status = 1
}
}
@ -149,8 +147,8 @@ $1 ~ /^#/ { next }
ruleUsed[$2] = 1
if ($3 ~ /%/) rulePercentUsed[$2] = 1
}
if (tz && tz ~ /\//) {
if (!tztab[tz]) {
if (tz && tz ~ /\// && tz !~ /^Etc\//) {
if (!tztab[tz] && FILENAME != "backward") {
printf "%s: no data for '%s'\n", zone_table, tz \
>>"/dev/stderr"
status = 1
@ -173,7 +171,7 @@ END {
}
}
for (tz in tztab) {
if (!zoneSeen[tz]) {
if (!zoneSeen[tz] && tz !~ /^Etc\//) {
printf "%s:%d: no Zone table for '%s'\n", \
zone_table, tz2NR[tz], tz >>"/dev/stderr"
status = 1

44
contrib/tzdata/europe
View file

@ -68,7 +68,6 @@
# 0:00 GMT BST BDST Greenwich, British Summer
# 0:00 GMT IST Greenwich, Irish Summer
# 0:00 WET WEST WEMT Western Europe
# 0:19:32.13 AMT* NST* Amsterdam, Netherlands Summer (1835-1937)
# 1:00 BST British Standard (1968-1971)
# 1:00 IST GMT Irish Standard (1968-) with winter DST
# 1:00 CET CEST CEMT Central Europe
@ -506,9 +505,6 @@ Zone Europe/London -0:01:15 - LMT 1847 Dec 1 0:00s
1:00 - BST 1971 Oct 31 2:00u
0:00 GB-Eire %s 1996
0:00 EU GMT/BST
Link Europe/London Europe/Jersey
Link Europe/London Europe/Guernsey
Link Europe/London Europe/Isle_of_Man
# From Paul Eggert (2018-02-15):
# In January 2018 we discovered that the negative SAVE values in the
@ -1307,9 +1303,8 @@ Zone Europe/Helsinki 1:39:49 - LMT 1878 May 31
1:39:49 - HMT 1921 May # Helsinki Mean Time
2:00 Finland EE%sT 1983
2:00 EU EE%sT
# Åland Is
Link Europe/Helsinki Europe/Mariehamn
# See Europe/Helsinki.
# France
@ -1505,8 +1500,7 @@ Zone Europe/Berlin 0:53:28 - LMT 1893 Apr
# From Arthur David Olson (2012-03-03):
# Büsingen and Zurich have shared clocks since 1970.
Link Europe/Zurich Europe/Busingen
# See Europe/Zurich.
# Georgia
# Please see the "asia" file for Asia/Tbilisi.
@ -1800,8 +1794,9 @@ Zone Europe/Rome 0:49:56 - LMT 1866 Dec 12
1:00 Italy CE%sT 1980
1:00 EU CE%sT
Link Europe/Rome Europe/Vatican
Link Europe/Rome Europe/San_Marino
# Kosovo
# See Europe/Belgrade.
# Latvia
@ -1895,7 +1890,7 @@ Zone Europe/Riga 1:36:34 - LMT 1880
# I could confirm from the paper that Liechtenstein did in fact follow
# the same DST in 1941 and 1942 as Switzerland did.
Link Europe/Zurich Europe/Vaduz
# See Europe/Zurich.
# Lithuania
@ -2150,6 +2145,10 @@ Zone Europe/Monaco 0:29:32 - LMT 1892 Jun 1
# The data entries before 1945 are taken from
# https://www.staff.science.uu.nl/~gent0113/wettijd/wettijd.htm
# From Paul Eggert (2021-05-09):
# I invented the abbreviations AMT for Amsterdam Mean Time and NST for
# Netherlands Summer Time, used in the Netherlands from 1835 to 1937.
# Rule NAME FROM TO - IN ON AT SAVE LETTER/S
Rule Neth 1916 only - May 1 0:00 1:00 NST # Netherlands Summer Time
Rule Neth 1916 only - Oct 1 0:00 0 AMT # Amsterdam Mean Time
@ -2248,8 +2247,7 @@ Zone Europe/Oslo 0:43:00 - LMT 1895 Jan 1
# Haudegen did not surrender to the Allies until September 1945.
#
# All these events predate our cutoff date of 1970, so use Europe/Oslo
# for these regions.
Link Europe/Oslo Arctic/Longyearbyen
# for these regions; see 'backward'.
# Poland
@ -2376,12 +2374,10 @@ Rule Port 1943 1945 - Aug Sat>=25 22:00s 1:00 S
Rule Port 1944 1945 - Apr Sat>=21 22:00s 2:00 M
Rule Port 1946 only - Apr Sat>=1 23:00s 1:00 S
Rule Port 1946 only - Oct Sat>=1 23:00s 0 -
Rule Port 1947 1949 - Apr Sun>=1 2:00s 1:00 S
Rule Port 1947 1949 - Oct Sun>=1 2:00s 0 -
# Shanks & Pottenger say DST was observed in 1950; go with Whitman.
# Whitman says DST was not observed in 1950; go with Shanks & Pottenger.
# Whitman gives Oct lastSun for 1952 on; go with Shanks & Pottenger.
Rule Port 1951 1965 - Apr Sun>=1 2:00s 1:00 S
Rule Port 1951 1965 - Oct Sun>=1 2:00s 0 -
Rule Port 1947 1965 - Apr Sun>=1 2:00s 1:00 S
Rule Port 1947 1965 - Oct Sun>=1 2:00s 0 -
Rule Port 1977 only - Mar 27 0:00s 1:00 S
Rule Port 1977 only - Sep 25 0:00s 0 -
Rule Port 1978 1979 - Apr Sun>=1 0:00s 1:00 S
@ -3520,14 +3516,9 @@ Zone Europe/Belgrade 1:22:00 - LMT 1884
# Shanks & Pottenger don't give as much detail, so go with Koželj.
1:00 - CET 1982 Nov 27
1:00 EU CE%sT
Link Europe/Belgrade Europe/Ljubljana # Slovenia
Link Europe/Belgrade Europe/Podgorica # Montenegro
Link Europe/Belgrade Europe/Sarajevo # Bosnia and Herzegovina
Link Europe/Belgrade Europe/Skopje # North Macedonia
Link Europe/Belgrade Europe/Zagreb # Croatia
# Slovakia
Link Europe/Prague Europe/Bratislava
# See Europe/Prague.
# Slovenia
# See Europe/Belgrade.
@ -3683,6 +3674,9 @@ Zone Atlantic/Canary -1:01:36 - LMT 1922 Mar # Las Palmas de Gran C.
#
# Source: The newspaper "Dagens Nyheter", 1916-10-01, page 7 upper left.
# An extra-special abbreviation style is SET for Swedish Time (svensk
# normaltid) 1879-1899, 3° west of the Stockholm Observatory.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Stockholm 1:12:12 - LMT 1879 Jan 1
1:00:14 - SET 1900 Jan 1 # Swedish Time
@ -3995,7 +3989,7 @@ Zone Europe/Istanbul 1:55:52 - LMT 1880
2:00 1:00 EEST 2015 Nov 8 1:00u
2:00 EU EE%sT 2016 Sep 7
3:00 - +03
Link Europe/Istanbul Asia/Istanbul # Istanbul is in both continents.
# See the 'backward' file for Asia/Istanbul.
# Ukraine
#

8
contrib/tzdata/leap-seconds.list
View file

@ -204,10 +204,10 @@
# current -- the update time stamp, the data and the name of the file
# will not change.
#
# Updated through IERS Bulletin C61
# File expires on: 28 December 2021
# Updated through IERS Bulletin C62
# File expires on: 28 June 2022
#
#@ 3849638400
#@ 3865363200
#
2272060800 10 # 1 Jan 1972
2287785600 11 # 1 Jul 1972
@ -252,4 +252,4 @@
# the hash line is also ignored in the
# computation.
#
#h 2ab8253d d4380d28 75f01343 381504f8 8f8a4bfc
#h 599d45bf accd4b4f 8b60e46 49b623 7d13b825

8
contrib/tzdata/leapseconds
View file

@ -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 2021 Dec 28 00:00:00
#Expires 2022 Jun 28 00:00:00
# POSIX timestamps for the data in this file:
#updated 1467936000 (2016-07-08 00:00:00 UTC)
#expires 1640649600 (2021-12-28 00:00:00 UTC)
#expires 1656374400 (2022-06-28 00:00:00 UTC)
# Updated through IERS Bulletin C61
# File expires on: 28 December 2021
# Updated through IERS Bulletin C62
# File expires on: 28 June 2022

244
contrib/tzdata/northamerica
View file

@ -729,7 +729,11 @@ Zone America/Adak 12:13:22 - LMT 1867 Oct 19 12:44:35
-11:00 US B%sT 1983 Oct 30 2:00
-10:00 US AH%sT 1983 Nov 30
-10:00 US H%sT
# The following switches don't quite make our 1970 cutoff.
# The following switches don't make our 1970 cutoff.
#
# Kiska observed Tokyo date and time during Japanese occupation from
# 1942-06-06 to 1943-07-29, and similarly for Attu from 1942-06-07 to
# 1943-05-29 (all dates American). Both islands are now uninhabited.
#
# Shanks writes that part of southwest Alaska (e.g. Aniak)
# switched from -11:00 to -10:00 on 1968-09-22 at 02:00,
@ -1593,24 +1597,7 @@ Zone America/Moncton -4:19:08 - LMT 1883 Dec 9
# From Paul Eggert (2020-01-10):
# See America/Toronto for most of Quebec, including Montreal.
# See America/Halifax for the Îles de la Madeleine and the Listuguj reserve.
#
# Matthews and Vincent (1998) also write that Quebec east of the -63
# meridian is supposed to observe AST, but residents as far east as
# Natashquan use EST/EDT, and residents east of Natashquan use AST.
# The Quebec department of justice writes in
# "The situation in Minganie and Basse-Côte-Nord"
# https://www.justice.gouv.qc.ca/en/department/ministre/functions-and-responsabilities/legal-time-in-quebec/the-situation-in-minganie-and-basse-cote-nord/
# that the coastal strip from just east of Natashquan to Blanc-Sablon
# observes Atlantic standard time all year round.
# This common practice was codified into law as of 2007; see Legal Time Act,
# CQLR c T-5.1 <http://legisquebec.gouv.qc.ca/en/ShowDoc/cs/T-5.1>.
# For lack of better info, guess this practice began around 1970, contra to
# Shanks & Pottenger who have this region observing AST/ADT.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Blanc-Sablon -3:48:28 - LMT 1884
-4:00 Canada A%sT 1970
-4:00 - AST
# See America/Puerto_Rico for east of Natashquan.
# Ontario
@ -1649,54 +1636,6 @@ Zone America/Blanc-Sablon -3:48:28 - LMT 1884
# time became a comic failure in Orillia. Toronto Star 2017-07-08.
# https://www.thestar.com/news/insight/2017/07/08/bold-attempt-at-daylight-saving-time-became-a-comic-failure-in-orillia.html
# From Paul Eggert (1997-10-17):
# Mark Brader writes that an article in the 1997-10-14 Toronto Star
# says that Atikokan, Ontario currently does not observe DST,
# but will vote on 11-10 whether to use EST/EDT.
# He also writes that the Ontario Time Act (1990, Chapter T.9)
# http://www.gov.on.ca/MBS/english/publications/statregs/conttext.html
# says that Ontario east of 90W uses EST/EDT, and west of 90W uses CST/CDT.
# Officially Atikokan is therefore on CST/CDT, and most likely this report
# concerns a non-official time observed as a matter of local practice.
#
# From Paul Eggert (2000-10-02):
# Matthews and Vincent (1998) write that Atikokan, Pickle Lake, and
# New Osnaburgh observe CST all year, that Big Trout Lake observes
# CST/CDT, and that Upsala and Shebandowan observe EST/EDT, all in
# violation of the official Ontario rules.
#
# From Paul Eggert (2006-07-09):
# Chris Walton (2006-07-06) mentioned an article by Stephanie MacLellan in the
# 2005-07-21 Chronicle-Journal, which said:
#
# The clocks in Atikokan stay set on standard time year-round.
# This means they spend about half the time on central time and
# the other half on eastern time.
#
# For the most part, the system works, Mayor Dennis Brown said.
#
# "The majority of businesses in Atikokan deal more with Eastern
# Canada, but there are some that deal with Western Canada," he
# said. "I don't see any changes happening here."
#
# Walton also writes "Supposedly Pickle Lake and Mishkeegogamang
# [New Osnaburgh] follow the same practice."
# From Garry McKinnon (2006-07-14) via Chris Walton:
# I chatted with a member of my board who has an outstanding memory
# and a long history in Atikokan (and in the telecom industry) and he
# can say for certain that Atikokan has been practicing the current
# time keeping since 1952, at least.
# From Paul Eggert (2006-07-17):
# Shanks & Pottenger say that Atikokan has agreed with Rainy River
# 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
# entry since our cutoff date of 1970, so we can move
# America/Coral_Harbour to the 'backward' file.
# From Mark Brader (2010-03-06):
#
# Currently the database has:
@ -1842,11 +1781,7 @@ Zone America/Rainy_River -6:18:16 - LMT 1895
-6:00 Canada C%sT 1940 Sep 29
-6:00 1:00 CDT 1942 Feb 9 2:00s
-6:00 Canada C%sT
Zone America/Atikokan -6:06:28 - LMT 1895
-6:00 Canada C%sT 1940 Sep 29
-6:00 1:00 CDT 1942 Feb 9 2:00s
-6:00 Canada C%sT 1945 Sep 30 2:00
-5:00 - EST
# For Atikokan see America/Panama.
# Manitoba
@ -2037,60 +1972,6 @@ Zone America/Edmonton -7:33:52 - LMT 1906 Sep
# Shanks & Pottenger write that since 1970 most of this region has
# been like Vancouver.
# Dawson Creek uses MST. Much of east BC is like Edmonton.
# Matthews and Vincent (1998) write that Creston is like Dawson Creek.
# It seems though that (re: Creston) is not entirely correct:
# From Chris Walton (2011-12-01):
# There are two areas within the Canadian province of British Columbia
# that do not currently observe daylight saving:
# a) The Creston Valley (includes the town of Creston and surrounding area)
# b) The eastern half of the Peace River Regional District
# (includes the cities of Dawson Creek and Fort St. John)
# Earlier this year I stumbled across a detailed article about the time
# keeping history of Creston; it was written by Tammy Hardwick who is the
# manager of the Creston & District Museum. The article was written in May 2009.
# http://www.ilovecreston.com/?p=articles&t=spec&ar=260
# According to the article, Creston has not changed its clocks since June 1918.
# i.e. Creston has been stuck on UT-7 for 93 years.
# Dawson Creek, on the other hand, changed its clocks as recently as April 1972.
# Unfortunately the exact date for the time change in June 1918 remains
# unknown and will be difficult to ascertain. I e-mailed Tammy a few months
# ago to ask if Sunday June 2 was a reasonable guess. She said it was just
# as plausible as any other date (in June). She also said that after writing
# the article she had discovered another time change in 1916; this is the
# subject of another article which she wrote in October 2010.
# http://www.creston.museum.bc.ca/index.php?module=comments&uop=view_comment&cm+id=56
# Here is a summary of the three clock change events in Creston's history:
# 1. 1884 or 1885: adoption of Mountain Standard Time (GMT-7)
# Exact date unknown
# 2. Oct 1916: switch to Pacific Standard Time (GMT-8)
# Exact date in October unknown; Sunday October 1 is a reasonable guess.
# 3. June 1918: switch to Pacific Daylight Time (GMT-7)
# Exact date in June unknown; Sunday June 2 is a reasonable guess.
# note 1:
# On Oct 27/1918 when daylight saving ended in the rest of Canada,
# Creston did not change its clocks.
# note 2:
# During WWII when the Federal Government legislated a mandatory clock change,
# Creston did not oblige.
# note 3:
# There is no guarantee that Creston will remain on Mountain Standard Time
# (UTC-7) forever.
# The subject was debated at least once this year by the town Council.
# http://www.bclocalnews.com/kootenay_rockies/crestonvalleyadvance/news/116760809.html
# During a period WWII, summer time (Daylight saying) was mandatory in Canada.
# In Creston, that was handled by shifting the area to PST (-8:00) then applying
# summer time to cause the offset to be -7:00, the same as it had been before
# the change. It can be argued that the timezone abbreviation during this
# period should be PDT rather than MST, but that doesn't seem important enough
# (to anyone) to further complicate the rules.
# The transition dates (and times) are guesses.
# From Matt Johnson (2015-09-21):
# Fort Nelson, BC, Canada will cancel DST this year. So while previously they
@ -2144,10 +2025,7 @@ Zone America/Fort_Nelson -8:10:47 - LMT 1884
-8:00 Vanc P%sT 1987
-8:00 Canada P%sT 2015 Mar 8 2:00
-7:00 - MST
Zone America/Creston -7:46:04 - LMT 1884
-7:00 - MST 1916 Oct 1
-8:00 - PST 1918 Jun 2
-7:00 - MST
# For Creston see America/Phoenix.
# Northwest Territories, Nunavut, Yukon
@ -2929,64 +2807,61 @@ Zone America/Tijuana -7:48:04 - LMT 1922 Jan 1 0:11:56
# Anguilla
# Antigua and Barbuda
# See America/Port_of_Spain.
# See America/Puerto_Rico.
# Bahamas
#
# For 1899 Milne gives -5:09:29.5; round that.
#
# From P Chan (2020-11-27, corrected on 2020-12-02):
# There were two periods of DST observed in 1942-1945: 1942-05-01
# midnight to 1944-12-31 midnight and 1945-02-01 to 1945-10-17 midnight.
# "midnight" should mean 24:00 from the context.
#
# War Time Order 1942 [1942-05-01] and War Time (No. 2) Order 1942 [1942-09-29]
# Appendix to the Statutes of 7 George VI. and the Year 1942. p 34, 43
# https://books.google.com/books?id=5rlNAQAAIAAJ&pg=RA3-PA34
# https://books.google.com/books?id=5rlNAQAAIAAJ&pg=RA3-PA43
#
# War Time Order 1943 [1943-03-31] and War Time Order 1944 [1943-12-29]
# Appendix to the Statutes of 8 George VI. and the Year 1943. p 9-10, 28-29
# https://books.google.com/books?id=5rlNAQAAIAAJ&pg=RA4-PA9
# https://books.google.com/books?id=5rlNAQAAIAAJ&pg=RA4-PA28
#
# War Time Order 1945 [1945-01-31] and the Order which revoke War Time Order
# 1945 [1945-10-16] Appendix to the Statutes of 9 George VI. and the Year
# 1945. p 160, 247-248
# https://books.google.com/books?id=5rlNAQAAIAAJ&pg=RA6-PA160
# https://books.google.com/books?id=5rlNAQAAIAAJ&pg=RA6-PA247
#
# From Sue Williams (2006-12-07):
# The Bahamas announced about a month ago that they plan to change their DST
# rules to sync with the U.S. starting in 2007....
# http://www.jonesbahamas.com/?c=45&a=10412
# The Bahamas
# See America/Montreal.
# Rule NAME FROM TO - IN ON AT SAVE LETTER/S
Rule Bahamas 1942 only - May 1 24:00 1:00 W
Rule Bahamas 1944 only - Dec 31 24:00 0 S
Rule Bahamas 1945 only - Feb 1 0:00 1:00 W
Rule Bahamas 1945 only - Aug 14 23:00u 1:00 P # Peace
Rule Bahamas 1945 only - Oct 17 24:00 0 S
Rule Bahamas 1964 1975 - Oct lastSun 2:00 0 S
Rule Bahamas 1964 1975 - Apr lastSun 2:00 1:00 D
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Nassau -5:09:30 - LMT 1912 Mar 2
-5:00 Bahamas E%sT 1976
-5:00 US E%sT
# Barbados
# For 1899 Milne gives -3:58:29.2; round that.
# From P Chan (2020-12-09 and 2020-12-11):
# Standard time of GMT-4 was adopted in 1911.
# Definition of Time Act, 1911 (1911-7) [1911-08-28]
# 1912, Laws of Barbados (5 v.), OCLC Number: 919801291, Vol. 4, Image No. 522
# 1944, Laws of Barbados (5 v.), OCLC Number: 84548697, Vol. 4, Image No. 122
# http://llmc.com/browse.aspx?type=2&coll=85&div=297
#
# DST was observed in 1942-44.
# Defence (Daylight Saving) Regulations, 1942, 1942-04-13
# Defence (Daylight Saving) (Repeal) Regulations, 1942, 1942-08-22
# Defence (Daylight Saving) Regulations, 1943, 1943-04-16
# Defence (Daylight Saving) (Repeal) Regulations, 1943, 1943-09-01
# Defence (Daylight Saving) Regulations, 1944, 1944-03-21
# [Defence (Daylight Saving) (Amendment) Regulations 1944, 1944-03-28]
# Defence (Daylight Saving) (Repeal) Regulations, 1944, 1944-08-30
#
# 1914-, Subsidiary Legis., Annual Vols. OCLC Number: 226290591
# 1942: Image Nos. 527-528, 555-556
# 1943: Image Nos. 178-179, 198
# 1944: Image Nos. 113-115, 129
# http://llmc.com/titledescfull.aspx?type=2&coll=85&div=297&set=98437
#
# From Tim Parenti (2021-02-20):
# The transitions below are derived from P Chan's sources, except that the 1977
# through 1980 transitions are from Shanks & Pottenger since we have no better
# data there. Of particular note, the 1944 DST regulation only advanced the
# time to "exactly three and a half hours later than Greenwich mean time", as
# opposed to "three hours" in the 1942 and 1943 regulations.
# Rule NAME FROM TO - IN ON AT SAVE LETTER/S
Rule Barb 1942 only - Apr 19 5:00u 1:00 D
Rule Barb 1942 only - Aug 31 6:00u 0 S
Rule Barb 1943 only - May 2 5:00u 1:00 D
Rule Barb 1943 only - Sep 5 6:00u 0 S
Rule Barb 1944 only - Apr 10 5:00u 0:30 -
Rule Barb 1944 only - Sep 10 6:00u 0 S
Rule Barb 1977 only - Jun 12 2:00 1:00 D
Rule Barb 1977 1978 - Oct Sun>=1 2:00 0 S
Rule Barb 1978 1980 - Apr Sun>=15 2:00 1:00 D
Rule Barb 1979 only - Sep 30 2:00 0 S
Rule Barb 1980 only - Sep 25 2:00 0 S
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Barbados -3:58:29 - LMT 1924 # Bridgetown
-3:58:29 - BMT 1932 # Bridgetown Mean Time
Zone America/Barbados -3:58:29 - LMT 1911 Aug 28 # Bridgetown
-4:00 Barb A%sT 1944
-4:00 Barb AST/-0330 1945
-4:00 Barb A%sT
# Belize
@ -3148,6 +3023,9 @@ Zone Atlantic/Bermuda -4:19:18 - LMT 1890 # Hamilton
-4:00 Canada A%sT 1976
-4:00 US A%sT
# Caribbean Netherlands
# See America/Puerto_Rico.
# Cayman Is
# See America/Panama.
@ -3376,7 +3254,7 @@ Zone America/Havana -5:29:28 - LMT 1890
-5:00 Cuba C%sT
# Dominica
# See America/Port_of_Spain.
# See America/Puerto_Rico.
# Dominican Republic
@ -3428,7 +3306,7 @@ Zone America/El_Salvador -5:56:48 - LMT 1921 # San Salvador
# Guadeloupe
# St Barthélemy
# St Martin (French part)
# See America/Port_of_Spain.
# See America/Puerto_Rico.
# Guatemala
#
@ -3615,7 +3493,7 @@ Zone America/Martinique -4:04:20 - LMT 1890 # Fort-de-France
-4:00 - AST
# Montserrat
# See America/Port_of_Spain.
# See America/Puerto_Rico.
# Nicaragua
#
@ -3687,7 +3565,6 @@ Zone America/Managua -5:45:08 - LMT 1890
Zone America/Panama -5:18:08 - LMT 1890
-5:19:36 - CMT 1908 Apr 22 # Colón Mean Time
-5:00 - EST
Link America/Panama America/Cayman
# Puerto Rico
# There are too many San Juans elsewhere, so we'll use 'Puerto_Rico'.
@ -3699,7 +3576,7 @@ Zone America/Puerto_Rico -4:24:25 - LMT 1899 Mar 28 12:00 # San Juan
# St Kitts-Nevis
# St Lucia
# See America/Port_of_Spain.
# See America/Puerto_Rico.
# St Pierre and Miquelon
# There are too many St Pierres elsewhere, so we'll use 'Miquelon'.
@ -3710,7 +3587,10 @@ Zone America/Miquelon -3:44:40 - LMT 1911 May 15 # St Pierre
-3:00 Canada -03/-02
# St Vincent and the Grenadines
# See America/Port_of_Spain.
# See America/Puerto_Rico.
# Sint Maarten
# See America/Puerto_Rico.
# Turks and Caicos
#
@ -3781,8 +3661,8 @@ Zone America/Grand_Turk -4:44:32 - LMT 1890
-5:00 US E%sT
# British Virgin Is
# Virgin Is
# See America/Port_of_Spain.
# US Virgin Is
# See America/Puerto_Rico.
# Local Variables:

87
contrib/tzdata/southamerica
View file

@ -574,7 +574,7 @@ Zone America/Argentina/Ushuaia -4:33:12 - LMT 1894 Oct 31
-3:00 - -03
# Aruba
Link America/Curacao America/Aruba
# See America/Puerto_Rico.
# Bolivia
# Zone NAME STDOFF RULES FORMAT [UNTIL]
@ -1369,35 +1369,14 @@ Zone America/Bogota -4:56:16 - LMT 1884 Mar 13
# no information; probably like America/Bogota
# Curaçao
# Milne gives 4:35:46.9 for Curaçao mean time; round to nearest.
# See America/Puerto_Rico.
#
# From Paul Eggert (2006-03-22):
# Shanks & Pottenger say that The Bottom and Philipsburg have been at
# -4:00 since standard time was introduced on 1912-03-02; and that
# Kralendijk and Rincon used Kralendijk Mean Time (-4:33:08) from
# 1912-02-02 to 1965-01-01. The former is dubious, since S&P also say
# Saba Island has been like Curaçao.
# This all predates our 1970 cutoff, though.
#
# By July 2007 Curaçao and St Maarten are planned to become
# associated states within the Netherlands, much like Aruba;
# Bonaire, Saba and St Eustatius would become directly part of the
# Netherlands as Kingdom Islands. This won't affect their time zones
# though, as far as we know.
#
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Curacao -4:35:47 - LMT 1912 Feb 12 # Willemstad
-4:30 - -0430 1965
-4:00 - AST
# From Arthur David Olson (2011-06-15):
# use links for places with new iso3166 codes.
# The name "Lower Prince's Quarter" is both longer than fourteen characters
# and contains an apostrophe; use "Lower_Princes" below.
Link America/Curacao America/Lower_Princes # Sint Maarten
Link America/Curacao America/Kralendijk # Caribbean Netherlands
# and contains an apostrophe; use "Lower_Princes"....
# From Paul Eggert (2021-05-06):
# These backward-compatibility links now are in the 'backward' file.
# Ecuador
#
@ -1540,11 +1519,40 @@ Zone America/Cayenne -3:29:20 - LMT 1911 Jul
-3:00 - -03
# Guyana
# From P Chan (2020-11-27):
# https://books.google.com/books?id=5-5CAQAAMAAJ&pg=SA1-PA547
# The Official Gazette of British Guiana. (New Series.) Vol. XL. July to
# December, 1915, p 1547, lists as several notes:
# "Local Mean Time 3 hours 52 mins. 39 secs. slow of Greenwich Mean Time
# (Georgetown.) From 1st August, 1911, British Guiana Standard Mean Time 4
# hours slow of Greenwich Mean Time, by notice in Official Gazette on 1st July,
# 1911. From 1st March, 1915, British Guiana Standard Mean Time 3 hours 45
# mins. 0 secs. slow of Greenwich Mean Time, by notice in Official Gazette on
# 23rd January, 1915."
#
# https://parliament.gov.gy/documents/acts/10923-act_no._27_of_1975_-_interpretation_and_general_clauses_(amendment)_act_1975.pdf
# Interpretation and general clauses (Amendment) Act 1975 (Act No. 27 of 1975)
# [dated 1975-07-31]
# "This Act...shall come into operation on 1st August, 1975."
# "...where any expression of time occurs...the time referred to shall signify
# the standard time of Guyana which shall be three hours behind Greenwich Mean
# Time."
#
# Circular No. 10/1992 dated 1992-03-20
# https://dps.gov.gy/wp-content/uploads/2018/12/1992-03-20-Circular-010.pdf
# "...cabinet has decided that with effect from Sunday 29th March, 1992, Guyana
# Standard Time would be re-established at 01:00 hours by adjusting the hands
# of the clock back to 24:00 hours."
# Legislated in the Interpretation and general clauses (Amendment) Act 1992
# (Act No. 6 of 1992) [passed 1992-03-27, published 1992-04-18]
# https://parliament.gov.gy/documents/acts/5885-6_of_1992_interpretation_and_general_clauses_(amendment)_act_1992.pdf
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Guyana -3:52:40 - LMT 1915 Mar # Georgetown
-3:45 - -0345 1975 Jul 31
-3:00 - -03 1991
# IATA SSIM (1996-06) says -4:00. Assume a 1991 switch.
Zone America/Guyana -3:52:39 - LMT 1911 Aug 1 # Georgetown
-4:00 - -04 1915 Mar 1
-3:45 - -0345 1975 Aug 1
-3:00 - -03 1992 Mar 29 1:00
-4:00 - -04
# Paraguay
@ -1685,24 +1693,7 @@ Zone America/Paramaribo -3:40:40 - LMT 1911
-3:00 - -03
# Trinidad and Tobago
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone America/Port_of_Spain -4:06:04 - LMT 1912 Mar 2
-4:00 - AST
# These all agree with Trinidad and Tobago since 1970.
Link America/Port_of_Spain America/Anguilla
Link America/Port_of_Spain America/Antigua
Link America/Port_of_Spain America/Dominica
Link America/Port_of_Spain America/Grenada
Link America/Port_of_Spain America/Guadeloupe
Link America/Port_of_Spain America/Marigot # St Martin (French part)
Link America/Port_of_Spain America/Montserrat
Link America/Port_of_Spain America/St_Barthelemy # St Barthélemy
Link America/Port_of_Spain America/St_Kitts # St Kitts & Nevis
Link America/Port_of_Spain America/St_Lucia
Link America/Port_of_Spain America/St_Thomas # Virgin Islands (US)
Link America/Port_of_Spain America/St_Vincent
Link America/Port_of_Spain America/Tortola # Virgin Islands (UK)
# See America/Puerto_Rico.
# Uruguay
# From Paul Eggert (1993-11-18):

39
contrib/tzdata/theory.html
View file

@ -42,12 +42,13 @@ href="https://en.wikipedia.org/wiki/Unix_time">POSIX Epoch</a>
(1970-01-01 00:00:00 <a
href="https://en.wikipedia.org/wiki/Coordinated_Universal_Time"><abbr
title="Coordinated Universal Time">UTC</abbr></a>).
The database labels each timezone with a notable location and
records all known clock transitions for that location.
Although 1970 is a somewhat-arbitrary cutoff, there are significant
challenges to moving the cutoff earlier even by a decade or two, due
to the wide variety of local practices before computer timekeeping
became prevalent.
Most timezones correspond to a notable location and the database
records all known clock transitions for that location;
some timezones correspond instead to a fixed <abbr>UTC</abbr> offset.
</p>
<p>
@ -58,8 +59,9 @@ specifies current standard time. For example, applications that deal
with current and future timestamps in the traditional North
American mountain time zone can choose from the timezones
<code>America/Denver</code> which observes US-style daylight saving
time, <code>America/Mazatlan</code> which observes Mexican-style DST,
and <code>America/Phoenix</code> which does not observe DST.
time (<abbr>DST</abbr>),
<code>America/Mazatlan</code> which observes Mexican-style <abbr>DST</abbr>,
and <code>America/Phoenix</code> which does not observe <abbr>DST</abbr>.
Applications that also deal with past timestamps in the mountain time
zone can choose from over a dozen timezones, such as
<code>America/Boise</code>, <code>America/Edmonton</code>, and
@ -68,7 +70,7 @@ time but differs from other timezones for some timestamps after 1970.
</p>
<p>
Clock transitions before 1970 are recorded for each timezone,
Clock transitions before 1970 are recorded for location-based timezones,
because most systems support timestamps before 1970 and could
misbehave if data entries were omitted for pre-1970 transitions.
However, the database is not designed for and does not suffice for
@ -190,8 +192,8 @@ in decreasing order of importance:
<code>TZ</code> strings</a>.
A file name component must not exceed 14 characters or start with
'<code>-</code>'.
E.g., prefer <code>Asia/Brunei</code> to
<code>Asia/Bandar_Seri_Begawan</code>.
E.g., prefer <code>America/Noronha</code> to
<code>America/Fernando_de_Noronha</code>.
Exceptions: see the discussion of legacy names below.
</li>
<li>
@ -473,10 +475,10 @@ in decreasing order of importance:
<p>
<small>These abbreviations are:
AMT Amsterdam, Asunción, Athens;
AMT Asunción, Athens;
BMT Baghdad, Bangkok, Batavia, Bermuda, Bern, Bogotá, Bridgetown,
Brussels, Bucharest;
CMT Calamarca, Caracas, Chisinau, Colón, Copenhagen, Córdoba;
CMT Calamarca, Caracas, Chisinau, Colón, Córdoba;
DMT Dublin/Dunsink;
EMT Easter;
FFMT Fort-de-France;
@ -499,7 +501,8 @@ in decreasing order of importance:
SMT Santiago, Simferopol, Singapore, Stanley;
TBMT Tbilisi;
TMT Tallinn, Tehran;
WMT Warsaw</small>.
WMT Warsaw;
ZMT Zomba.</small>
</p>
<p>
@ -513,9 +516,7 @@ in decreasing order of importance:
1880&ndash;1916,
MMT/MST/MDST for Moscow 1880&ndash;1919, and
RMT/LST for Riga Mean Time and Latvian Summer time 1880&ndash;1926.
An extra-special case is SET for Swedish Time (<em>svensk
normaltid</em>) 1879&ndash;1899, 3&deg; west of the Stockholm
Observatory.</small>
</small>
</p>
</li>
<li>
@ -702,11 +703,9 @@ href="https://www.dissentmagazine.org/blog/booked-a-global-history-of-time-vanes
<li>
Sometimes historical timekeeping was specified more precisely
than what the <code><abbr>tz</abbr></code> code can handle.
For example, from 1909 to 1937 <a
href="https://www.staff.science.uu.nl/~gent0113/wettijd/wettijd.htm"
hreflang="nl">Netherlands clocks</a> were legally Amsterdam Mean
For example, from 1880 to 1916 clocks in Ireland observed Dublin Mean
Time (estimated to be <abbr>UT</abbr>
+00:19:32.13), but the <code><abbr>tz</abbr></code>
&minus;00:25:21.1), but the <code><abbr>tz</abbr></code>
code cannot represent the fractional second.
In practice these old specifications were rarely if ever
implemented to subsecond precision.
@ -753,7 +752,8 @@ href="https://www.dissentmagazine.org/blog/booked-a-global-history-of-time-vanes
the Western 06:00 to be 12:00. These practices are largely outside
the scope of the <code><abbr>tz</abbr></code> code and data, which
provide only limited support for date and time localization
such as that required by POSIX. If DST is not used a different time zone
such as that required by POSIX.
If <abbr>DST</abbr> is not used a different time zone
can often do the trick; for example, in Kenya a <code>TZ</code> setting
like <code>&lt;-03&gt;3</code> or <code>America/Cayenne</code> starts
the day six hours later than <code>Africa/Nairobi</code> does.
@ -1271,7 +1271,8 @@ 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>
at the same point that time zone and DST adjustments are applied &ndash;
at the same point that time zone and <abbr>DST</abbr>
adjustments are applied &ndash;
namely, at calls to <code>localtime</code> and analogous functions &ndash;
and the process is driven by leap second information
stored in alternate versions of the <abbr>TZif</abbr> files.

2
contrib/tzdata/version
View file

@ -1 +1 @@
2021a
2021b

11
contrib/tzdata/ziguard.awk
View file

@ -114,15 +114,16 @@ DATAFORM != "main" {
}
}
# If a Link line is followed by a Zone line for the same data, comment
# If a Link line is followed by a Link or Zone line for the same data, comment
# out the Link line. This can happen if backzone overrides a Link
# with a Zone.
/^Link/ {
linkline[$3] = NR
}
# with a Zone or a different Link.
/^Zone/ {
sub(/^Link/, "#Link", line[linkline[$2]])
}
/^Link/ {
sub(/^Link/, "#Link", line[linkline[$3]])
linkline[$3] = NR
}
{ line[NR] = $0 }

9
contrib/tzdata/zone.tab
View file

@ -3,7 +3,7 @@
# This file is in the public domain, so clarified as of
# 2009-05-17 by Arthur David Olson.
#
# From Paul Eggert (2018-06-27):
# From Paul Eggert (2021-09-20):
# This file is intended as a backward-compatibility aid for older programs.
# New programs should use zone1970.tab. This file is like zone1970.tab (see
# zone1970.tab's comments), but with the following additional restrictions:
@ -16,6 +16,9 @@
# clocks have agreed since 1970; this is a narrower definition than
# that of zone1970.tab.
#
# Unlike zone1970.tab, a row's third column can be a Link from
# 'backward' instead of a Zone.
#
# This table is intended as an aid for users, to help them select timezones
# appropriate for their practical needs. It is not intended to take or
# endorse any position on legal or territorial claims.
@ -228,7 +231,7 @@ KE -0117+03649 Africa/Nairobi
KG +4254+07436 Asia/Bishkek
KH +1133+10455 Asia/Phnom_Penh
KI +0125+17300 Pacific/Tarawa Gilbert Islands
KI -0308-17105 Pacific/Enderbury Phoenix Islands
KI -0247-17143 Pacific/Kanton Phoenix Islands
KI +0152-15720 Pacific/Kiritimati Line Islands
KM -1141+04316 Indian/Comoro
KN +1718-06243 America/St_Kitts
@ -391,7 +394,7 @@ TK -0922-17114 Pacific/Fakaofo
TL -0833+12535 Asia/Dili
TM +3757+05823 Asia/Ashgabat
TN +3648+01011 Africa/Tunis
TO -2110-17510 Pacific/Tongatapu
TO -210800-1751200 Pacific/Tongatapu
TR +4101+02858 Europe/Istanbul
TT +1039-06131 America/Port_of_Spain
TV -0831+17913 Pacific/Funafuti

29
contrib/tzdata/zone1970.tab
View file

@ -41,11 +41,9 @@ AL +4120+01950 Europe/Tirane
AM +4011+04430 Asia/Yerevan
AQ -6617+11031 Antarctica/Casey Casey
AQ -6835+07758 Antarctica/Davis Davis
AQ -6640+14001 Antarctica/DumontDUrville Dumont-d'Urville
AQ -6736+06253 Antarctica/Mawson Mawson
AQ -6448-06406 Antarctica/Palmer Palmer
AQ -6734-06808 Antarctica/Rothera Rothera
AQ -690022+0393524 Antarctica/Syowa Syowa
AQ -720041+0023206 Antarctica/Troll Troll
AQ -7824+10654 Antarctica/Vostok Vostok
AR -3436-05827 America/Argentina/Buenos_Aires Buenos Aires (BA, CF)
@ -98,7 +96,6 @@ BR +0249-06040 America/Boa_Vista Roraima
BR -0308-06001 America/Manaus Amazonas (east)
BR -0640-06952 America/Eirunepe Amazonas (west)
BR -0958-06748 America/Rio_Branco Acre
BS +2505-07721 America/Nassau
BT +2728+08939 Asia/Thimphu
BY +5354+02734 Europe/Minsk
BZ +1730-08812 America/Belize
@ -107,13 +104,11 @@ CA +4439-06336 America/Halifax Atlantic - NS (most areas); PE
CA +4612-05957 America/Glace_Bay Atlantic - NS (Cape Breton)
CA +4606-06447 America/Moncton Atlantic - New Brunswick
CA +5320-06025 America/Goose_Bay Atlantic - Labrador (most areas)
CA +5125-05707 America/Blanc-Sablon AST - QC (Lower North Shore)
CA +4339-07923 America/Toronto Eastern - ON, QC (most areas)
CA,BS +4339-07923 America/Toronto Eastern - ON, QC (most areas), Bahamas
CA +4901-08816 America/Nipigon Eastern - ON, QC (no DST 1967-73)
CA +4823-08915 America/Thunder_Bay Eastern - ON (Thunder Bay)
CA +6344-06828 America/Iqaluit Eastern - NU (most east areas)
CA +6608-06544 America/Pangnirtung Eastern - NU (Pangnirtung)
CA +484531-0913718 America/Atikokan EST - ON (Atikokan); NU (Coral H)
CA +4953-09709 America/Winnipeg Central - ON (west); Manitoba
CA +4843-09434 America/Rainy_River Central - ON (Rainy R, Ft Frances)
CA +744144-0944945 America/Resolute Central - NU (Resolute)
@ -124,7 +119,6 @@ CA +5333-11328 America/Edmonton Mountain - AB; BC (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 +5946-12014 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)
@ -132,7 +126,7 @@ CA +6404-13925 America/Dawson MST - Yukon (west)
CA +4916-12307 America/Vancouver Pacific - BC (most areas)
CC -1210+09655 Indian/Cocos
CH,DE,LI +4723+00832 Europe/Zurich Swiss time
CI,BF,GM,GN,ML,MR,SH,SL,SN,TG +0519-00402 Africa/Abidjan
CI,BF,GH,GM,GN,ML,MR,SH,SL,SN,TG +0519-00402 Africa/Abidjan
CK -2114-15946 Pacific/Rarotonga
CL -3327-07040 America/Santiago Chile (most areas)
CL -5309-07055 America/Punta_Arenas Region of Magallanes
@ -143,7 +137,6 @@ CO +0436-07405 America/Bogota
CR +0956-08405 America/Costa_Rica
CU +2308-08222 America/Havana
CV +1455-02331 Atlantic/Cape_Verde
CW,AW,BQ,SX +1211-06900 America/Curacao
CX -1025+10543 Indian/Christmas
CY +3510+03322 Asia/Nicosia Cyprus (most areas)
CY +3507+03357 Asia/Famagusta Northern Cyprus
@ -171,7 +164,6 @@ FR +4852+00220 Europe/Paris
GB,GG,IM,JE +513030-0000731 Europe/London
GE +4143+04449 Asia/Tbilisi
GF +0456-05220 America/Cayenne
GH +0533-00013 Africa/Accra
GI +3608-00521 Europe/Gibraltar
GL +6411-05144 America/Nuuk Greenland (most areas)
GL +7646-01840 America/Danmarkshavn National Park (east coast)
@ -205,7 +197,7 @@ 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 +0125+17300 Pacific/Tarawa Gilbert Islands
KI -0308-17105 Pacific/Enderbury Phoenix Islands
KI -0247-17143 Pacific/Kanton Phoenix Islands
KI +0152-15720 Pacific/Kiritimati Line Islands
KP +3901+12545 Asia/Pyongyang
KR +3733+12658 Asia/Seoul
@ -263,19 +255,19 @@ 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,KY +0858-07932 America/Panama
PA,CA,KY +0858-07932 America/Panama EST - Panama, Cayman, ON (Atikokan), NU (Coral H)
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,AQ -0930+14710 Pacific/Port_Moresby Papua New Guinea (most areas), Dumont d'Urville
PG -0613+15534 Pacific/Bougainville Bougainville
PH +1435+12100 Asia/Manila
PK +2452+06703 Asia/Karachi
PL +5215+02100 Europe/Warsaw
PM +4703-05620 America/Miquelon
PN -2504-13005 Pacific/Pitcairn
PR +182806-0660622 America/Puerto_Rico
PR,AG,CA,AI,AW,BL,BQ,CW,DM,GD,GP,KN,LC,MF,MS,SX,TT,VC,VG,VI +182806-0660622 America/Puerto_Rico AST
PS +3130+03428 Asia/Gaza Gaza Strip
PS +313200+0350542 Asia/Hebron West Bank
PT +3843-00908 Europe/Lisbon Portugal (mainland)
@ -315,12 +307,12 @@ RU +4658+14242 Asia/Sakhalin MSK+08 - Sakhalin Island
RU +6728+15343 Asia/Srednekolymsk MSK+08 - Sakha (E); North Kuril Is
RU +5301+15839 Asia/Kamchatka MSK+09 - Kamchatka
RU +6445+17729 Asia/Anadyr MSK+09 - Bering Sea
SA,KW,YE +2438+04643 Asia/Riyadh
SA,AQ,KW,YE +2438+04643 Asia/Riyadh Arabia, Syowa
SB -0932+16012 Pacific/Guadalcanal
SC -0440+05528 Indian/Mahe
SD +1536+03232 Africa/Khartoum
SE +5920+01803 Europe/Stockholm
SG +0117+10351 Asia/Singapore
SG,MY +0117+10351 Asia/Singapore Singapore, peninsular Malaysia
SR +0550-05510 America/Paramaribo
SS +0451+03137 Africa/Juba
ST +0020+00644 Africa/Sao_Tome
@ -335,9 +327,8 @@ TK -0922-17114 Pacific/Fakaofo
TL -0833+12535 Asia/Dili
TM +3757+05823 Asia/Ashgabat
TN +3648+01011 Africa/Tunis
TO -2110-17510 Pacific/Tongatapu
TO -210800-1751200 Pacific/Tongatapu
TR +4101+02858 Europe/Istanbul
TT,AG,AI,BL,DM,GD,GP,KN,LC,MF,MS,VC,VG,VI +1039-06131 America/Port_of_Spain
TV -0831+17913 Pacific/Funafuti
TW +2503+12130 Asia/Taipei
UA +5026+03031 Europe/Kiev Ukraine (most areas)
@ -363,7 +354,7 @@ 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,CA +332654-1120424 America/Phoenix MST - Arizona (except Navajo), 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