Import tzdata 2019a
This commit is contained in:
Philip Paeps
parent
b17a2172ab
commit
beecab9423
29
Makefile
29
Makefile
@ -12,7 +12,10 @@ VERSION= unknown
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# Email address for bug reports.
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BUGEMAIL= tz@iana.org
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# Choose source data features. To get new features right away, use:
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# DATAFORM selects the data format.
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# Available formats represent essentially the same data, albeit
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# possibly with minor discrepancies that users are not likely to notice.
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# To get new features and the best data right away, use:
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# DATAFORM= vanguard
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# To wait a while before using new features, to give downstream users
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# time to upgrade zic (the default), use:
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@ -33,11 +36,11 @@ DATAFORM= main
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LOCALTIME= GMT
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# If you want something other than Eastern United States time as a template
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# for handling POSIX-style timezone environment variables,
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# for handling ruleless POSIX-style timezone environment variables,
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# change the line below (after finding the timezone you want in the
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# one of the $(TDATA) source files, or adding it to a source file).
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# When a POSIX-style environment variable is handled, the rules in the
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# template file are used to determine "spring forward" and "fall back" days and
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# A ruleless environment setting like TZ='CST6CDT' uses the rules in the
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# template file to determine "spring forward" and "fall back" days and
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# times; the environment variable itself specifies UT offsets of standard and
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# daylight saving time.
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# Alternatively, if you discover you've got the wrong timezone, you can just
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@ -46,7 +49,6 @@ LOCALTIME= GMT
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# Use the command
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# make zonenames
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# to get a list of the values you can use for POSIXRULES.
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# If you want POSIX compatibility, use "America/New_York".
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POSIXRULES= America/New_York
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@ -113,8 +115,8 @@ TIME_T_ALTERNATIVES = $(TIME_T_ALTERNATIVES_HEAD) $(TIME_T_ALTERNATIVES_TAIL)
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TIME_T_ALTERNATIVES_HEAD = int64_t
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TIME_T_ALTERNATIVES_TAIL = int32_t uint32_t uint64_t
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# What kind of TZif data files to generate.
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# (TZif is the binary time zone data format that zic generates.)
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# What kind of TZif data files to generate. (TZif is the binary time
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# zone data format that zic generates; see Internet RFC 8536.)
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# If you want only POSIX time, with time values interpreted as
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# seconds since the epoch (not counting leap seconds), use
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# REDO= posix_only
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@ -360,6 +362,9 @@ LEAPSECONDS=
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zic= ./zic
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ZIC= $(zic) $(ZFLAGS)
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# To shrink the size of installed TZif files,
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# append "-r @N" to omit data before N-seconds-after-the-Epoch.
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# See the zic man page for more about -r.
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ZFLAGS=
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# How to use zic to install TZif files.
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@ -491,7 +496,8 @@ MANTXTS= newctime.3.txt newstrftime.3.txt newtzset.3.txt \
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COMMON= calendars CONTRIBUTING LICENSE Makefile \
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NEWS README theory.html version
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WEB_PAGES= tz-art.html tz-how-to.html tz-link.html
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CHECK_WEB_PAGES=check_tz-art.html check_tz-how-to.html check_tz-link.html
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CHECK_WEB_PAGES=check_theory.html check_tz-art.html \
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check_tz-how-to.html check_tz-link.html
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DOCS= $(MANS) date.1 $(MANTXTS) $(WEB_PAGES)
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PRIMARY_YDATA= africa antarctica asia australasia \
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europe northamerica southamerica
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@ -804,9 +810,10 @@ check_tzs: $(TZS) $(TZS_NEW)
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touch $@
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check_web: $(CHECK_WEB_PAGES)
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check_theory.html: theory.html
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check_tz-art.html: tz-art.html
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check_tz-link.html: tz-link.html
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check_tz-art.html check_tz-link.html:
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check_theory.html check_tz-art.html check_tz-link.html:
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$(CURL) -sS --url https://validator.w3.org/nu/ -F out=gnu \
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-F file=@$$(expr $@ : 'check_\(.*\)') -o $@.out && \
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test ! -s $@.out || { cat $@.out; exit 1; }
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@ -840,11 +847,13 @@ check_zishrink_posix check_zishrink_right: \
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touch $@
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clean_misc:
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rm -fr check_*.dir
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rm -f *.o *.out $(TIME_T_ALTERNATIVES) \
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check_* core typecheck_* \
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date tzselect version.h zdump zic yearistype libtz.a
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clean: clean_misc
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rm -fr *.dir *.zi tzdb-*/ $(TZS_NEW)
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rm -fr *.dir tzdb-*/
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rm -f *.zi $(TZS_NEW)
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maintainer-clean: clean
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@echo 'This command is intended for maintainers to use; it'
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53
NEWS
53
NEWS
@ -1,5 +1,53 @@
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News for the tz database
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Release 20198 - 2019-03-25 22:01:33 -0700
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Briefly:
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Palestine "springs forward" on 2019-03-30 instead of 2019-03-23.
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Metlakatla "fell back" to rejoin Alaska Time on 2019-01-20 at 02:00.
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Changes to past and future timestamps
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Palestine will not start DST until 2019-03-30, instead of 2019-03-23 as
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previously predicted. Adjust our prediction by guessing that spring
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transitions will be between 24 and 30 March, which matches recent practice
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since 2016. (Thanks to Even Scharning and Tim Parenti.)
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Metlakatla ended its observance of Pacific standard time,
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rejoining Alaska Time, on 2019-01-20 at 02:00. (Thanks to Ryan
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Stanley and Tim Parenti.)
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Changes to past timestamps
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Israel observed DST in 1980 (08-02/09-13) and 1984 (05-05/08-25).
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(Thanks to Alois Treindl and Isaac Starkman.)
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Changes to time zone abbreviations
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Etc/UCT is now a backward-compatibility link to Etc/UTC, instead
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of being a separate zone that generates the abbreviation "UCT",
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which nowadays is typically a typo. (Problem reported by Isiah
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Meadows.)
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Changes to code
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zic now has an -r option to limit the time range of output data.
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For example, 'zic -r @1000000000' limits the output data to
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timestamps starting 1000000000 seconds after the Epoch.
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This helps shrink output size and can be useful for applications
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not needing the full timestamp history, such as TZDIST truncation;
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see Internet RFC 8536 section 5.1. (Inspired by a feature request
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from Christopher Wong, helped along by bug reports from Wong and
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from Tim Parenti.)
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Changes to documentation
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Mention Internet RFC 8536 (February 2019), which documents TZif.
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tz-link.html now cites tzdata-meta
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<https://tzdata-meta.timtimeonline.com/>.
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Release 2018i - 2018-12-30 11:05:43 -0800
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Briefly:
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@ -400,8 +448,9 @@ Release 2018d - 2018-03-22 07:05:46 -0700
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downstream parsers do not support it.
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* The build procedure constructs three files vanguard.zi, main.zi,
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and rearguard.zi, one for each format. The files represent the
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same data as closely as the formats allow. These three files
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and rearguard.zi, one for each format. Although the files
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represent essentially the same data, they may have minor
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discrepancies that users are not likely to notice. The files
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are intended for downstream data consumers and are not
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installed. Zoneinfo parsers that do not support negative SAVE values
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should start using rearguard.zi, so that they will be unaffected
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4
README
4
README
@ -1,7 +1,7 @@
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README for the tz distribution
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"What time is it?" -- Richard Deacon as The King
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"Any time you want it to be." -- Frank Baxter as The Scientist
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"Where do I set the hands of the clock?" -- Les Tremayne as The King
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"Oh that--you can set them any place you want." -- Frank Baxter as The Scientist
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(from the Bell System film "About Time")
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The Time Zone Database (called tz, tzdb or zoneinfo) contains code and
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10
africa
10
africa
@ -364,6 +364,11 @@ Zone Africa/Cairo 2:05:09 - LMT 1900 Oct
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# See Africa/Lagos.
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# Eritrea
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# See Africa/Nairobi.
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# Eswatini (formerly Swaziland)
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# See Africa/Johannesburg.
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# Ethiopia
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# See Africa/Nairobi.
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#
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@ -1188,7 +1193,7 @@ Zone Africa/Johannesburg 1:52:00 - LMT 1892 Feb 8
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1:30 - SAST 1903 Mar
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2:00 SA SAST
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Link Africa/Johannesburg Africa/Maseru # Lesotho
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Link Africa/Johannesburg Africa/Mbabane # Swaziland
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Link Africa/Johannesburg Africa/Mbabane # Eswatini
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#
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# Marion and Prince Edward Is
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# scientific station since 1947
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@ -1230,9 +1235,6 @@ Zone Africa/Juba 2:06:28 - LMT 1931
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2:00 Sudan CA%sT 2000 Jan 15 12:00
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3:00 - EAT
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# Swaziland
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# See Africa/Johannesburg.
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# Tanzania
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# See Africa/Nairobi.
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42
asia
42
asia
@ -1620,6 +1620,24 @@ Rule Zion 1974 only - Jul 7 0:00 1:00 D
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Rule Zion 1974 only - Oct 13 0:00 0 S
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Rule Zion 1975 only - Apr 20 0:00 1:00 D
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Rule Zion 1975 only - Aug 31 0:00 0 S
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# From Alois Treindl (2019-03-06):
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# http://www.moin.gov.il/Documents/שעון קיץ/clock-50-years-7-2014.pdf
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# From Isaac Starkman (2019-03-06):
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# Summer time was in that period in 1980 and 1984, see
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# https://www.ynet.co.il/articles/0,7340,L-3951073,00.html
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# You can of course read it in translation.
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# I checked the local newspapers for that years.
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# It started on midnight and end at 01.00 am.
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# From Paul Eggert (2019-03-06):
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# Also see this thread about the moin.gov.il URL:
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# https://mm.icann.org/pipermail/tz/2018-November/027194.html
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Rule Zion 1980 only - Aug 2 0:00 1:00 D
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Rule Zion 1980 only - Sep 13 1:00 0 S
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Rule Zion 1984 only - May 5 0:00 1:00 D
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Rule Zion 1984 only - Aug 25 1:00 0 S
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# From Shanks & Pottenger:
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Rule Zion 1985 only - Apr 14 0:00 1:00 D
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Rule Zion 1985 only - Sep 15 0:00 0 S
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Rule Zion 1986 only - May 18 0:00 1:00 D
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@ -3071,9 +3089,15 @@ Zone Asia/Karachi 4:28:12 - LMT 1907
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# the official website, though the decree did not specify the exact
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# time of the time shift.
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# http://www.palestinecabinet.gov.ps/Website/AR/NDecrees/ViewFile.ashx?ID=e7a42ab7-ee23-435a-b9c8-a4f7e81f3817
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# From Even Scharning (2019-03-23):
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# DST in Palestine will start on 30 March this year, not 23 March as the time
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# zone database predicted.
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# https://ramallah.news/post/123610
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#
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# From Paul Eggert (2018-03-16):
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# For 2016 on, predict spring transitions on March's fourth Saturday at 01:00.
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# From Tim Parenti (2019-03-23):
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# Combining this with the rules observed since 2016, adjust our spring
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# transition guess to Mar Sat>=24.
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# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
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Rule EgyptAsia 1957 only - May 10 0:00 1:00 S
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@ -3104,7 +3128,7 @@ Rule Palestine 2012 only - Sep 21 1:00 0 -
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Rule Palestine 2013 only - Sep Fri>=21 0:00 0 -
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Rule Palestine 2014 2015 - Oct Fri>=21 0:00 0 -
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Rule Palestine 2015 only - Mar lastFri 24:00 1:00 S
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Rule Palestine 2016 max - Mar Sat>=22 1:00 1:00 S
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Rule Palestine 2016 max - Mar Sat>=24 1:00 1:00 S
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Rule Palestine 2016 max - Oct lastSat 1:00 0 -
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# Zone NAME GMTOFF RULES FORMAT [UNTIL]
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@ -3596,5 +3620,17 @@ Zone Asia/Ho_Chi_Minh 7:06:40 - LMT 1906 Jul 1
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8:00 - +08 1975 Jun 13
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7:00 - +07
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# From Paul Eggert (2019-02-19):
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#
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# The Ho Chi Minh entry suffices for most purposes as it agrees with all of
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# Vietnam since 1975-06-13. Presumably clocks often changed in south Vietnam
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# in the early 1970s as locations changed hands during the war; however the
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# details are unknown and would likely be too voluminous for this database.
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#
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# For timestamps in north Vietnam back to 1970 (the tzdb cutoff),
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# use Asia/Bangkok; see the VN entries in the file zone1970.tab.
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# For timestamps before 1970, see Asia/Hanoi in the file 'backzone'.
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# Yemen
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# See Asia/Riyadh.
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3
backward
3
backward
@ -77,6 +77,7 @@ Link Pacific/Easter Chile/EasterIsland
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Link America/Havana Cuba
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Link Africa/Cairo Egypt
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Link Europe/Dublin Eire
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Link Etc/UTC Etc/UCT
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Link Europe/London Europe/Belfast
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Link Europe/Chisinau Europe/Tiraspol
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Link Europe/London GB
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@ -111,7 +112,7 @@ Link Asia/Taipei ROC
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Link Asia/Seoul ROK
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Link Asia/Singapore Singapore
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Link Europe/Istanbul Turkey
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Link Etc/UCT UCT
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Link Etc/UTC UCT
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Link America/Anchorage US/Alaska
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Link America/Adak US/Aleutian
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Link America/Phoenix US/Arizona
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4
backzone
4
backzone
@ -204,7 +204,7 @@ Zone Africa/Maseru 1:50:00 - LMT 1903 Mar
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2:00 1:00 SAST 1944 Mar 19 2:00
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2:00 - SAST
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# Swaziland
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# Eswatini (formerly Swaziland)
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Zone Africa/Mbabane 2:04:24 - LMT 1903 Mar
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2:00 - SAST
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@ -625,7 +625,7 @@ Zone Europe/Sarajevo 1:13:40 - LMT 1884
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1:00 - CET 1982 Nov 27
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1:00 EU CE%sT
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# Macedonia
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# North Macedonia
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Zone Europe/Skopje 1:25:44 - LMT 1884
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1:00 - CET 1941 Apr 18 23:00
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1:00 C-Eur CE%sT 1945 May 8 2:00s
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1
etcetera
1
etcetera
@ -19,7 +19,6 @@
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Zone Etc/GMT 0 - GMT
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Zone Etc/UTC 0 - UTC
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Zone Etc/UCT 0 - UCT
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# The following link uses older naming conventions,
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# but it belongs here, not in the file 'backward',
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4
europe
4
europe
@ -1855,7 +1855,7 @@ Zone Europe/Luxembourg 0:24:36 - LMT 1904 Jun
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1:00 Belgium CE%sT 1977
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1:00 EU CE%sT
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# Macedonia
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# North Macedonia
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# See Europe/Belgrade.
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# Malta
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@ -3359,7 +3359,7 @@ Zone Europe/Belgrade 1:22:00 - LMT 1884
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Link Europe/Belgrade Europe/Ljubljana # Slovenia
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Link Europe/Belgrade Europe/Podgorica # Montenegro
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Link Europe/Belgrade Europe/Sarajevo # Bosnia and Herzegovina
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Link Europe/Belgrade Europe/Skopje # Macedonia
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Link Europe/Belgrade Europe/Skopje # North Macedonia
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Link Europe/Belgrade Europe/Zagreb # Croatia
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# Slovakia
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@ -9,8 +9,8 @@
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# All text uses UTF-8 encoding. The columns of the table are as follows:
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#
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# 1. ISO 3166-1 alpha-2 country code, current as of
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# ISO 3166-1 N905 (2016-11-15). See: Updates on ISO 3166-1
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# http://isotc.iso.org/livelink/livelink/Open/16944257
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# ISO 3166-1 N976 (2018-11-06). See: Updates on ISO 3166-1
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# https://isotc.iso.org/livelink/livelink/Open/16944257
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# 2. The usual English name for the coded region,
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# chosen so that alphabetic sorting of subsets produces helpful lists.
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# This is not the same as the English name in the ISO 3166 tables.
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@ -166,7 +166,7 @@ ME Montenegro
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MF St Martin (French)
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MG Madagascar
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MH Marshall Islands
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MK Macedonia
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MK North Macedonia
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ML Mali
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MM Myanmar (Burma)
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MN Mongolia
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@ -235,7 +235,7 @@ ST Sao Tome & Principe
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SV El Salvador
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SX St Maarten (Dutch)
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SY Syria
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SZ Swaziland
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SZ Eswatini (Swaziland)
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TC Turks & Caicos Is
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TD Chad
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TF French Southern & Antarctic Lands
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@ -204,10 +204,10 @@
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# current -- the update time stamp, the data and the name of the file
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# will not change.
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#
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# Updated through IERS Bulletin C56
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# File expires on: 28 June 2019
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# Updated through IERS Bulletin C57
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# File expires on: 28 December 2019
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#
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#@ 3770668800
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#@ 3786480000
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#
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2272060800 10 # 1 Jan 1972
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2287785600 11 # 1 Jul 1972
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@ -252,4 +252,4 @@
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# the hash line is also ignored in the
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# computation.
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#
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#h 62ca19f6 96a4ae0a 3708451c 9f8693f4 016604eb
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#h 83c68138 d3650221 07dbbbcd 11fcc859 ced1106a
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@ -63,7 +63,7 @@ Leap 2016 Dec 31 23:59:60 + S
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# POSIX timestamps for the data in this file:
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#updated 1467936000
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#expires 1561680000
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#expires 1577491200
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# Updated through IERS Bulletin C56
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# File expires on: 28 June 2019
|
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# Updated through IERS Bulletin C57
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# File expires on: 28 December 2019
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11
northamerica
11
northamerica
@ -609,6 +609,15 @@ Zone America/Los_Angeles -7:52:58 - LMT 1883 Nov 18 12:07:02
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# In a 2018-12-11 special election, Metlakatla voted to go back to
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# Alaska time (including daylight saving time) starting next year.
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# https://www.krbd.org/2018/12/12/metlakatla-to-follow-alaska-standard-time-allow-liquor-sales/
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#
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# From Ryan Stanley (2019-01-11):
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# The community will be changing back on the 20th of this month...
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# From Tim Parenti (2019-01-11):
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# Per an announcement on the Metlakatla community's official Facebook page, the
|
||||
# "fall back" will be on Sunday 2019-01-20 at 02:00:
|
||||
# https://www.facebook.com/141055983004923/photos/607150969728753/
|
||||
# So they won't be waiting for Alaska to join them on 2019-03-10, but will
|
||||
# rather change their clocks twice in seven weeks.
|
||||
|
||||
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
|
||||
Zone America/Juneau 15:02:19 - LMT 1867 Oct 19 15:33:32
|
||||
@ -637,7 +646,7 @@ Zone America/Metlakatla 15:13:42 - LMT 1867 Oct 19 15:44:55
|
||||
-8:00 US P%sT 1983 Oct 30 2:00
|
||||
-8:00 - PST 2015 Nov 1 2:00
|
||||
-9:00 US AK%sT 2018 Nov 4 2:00
|
||||
-8:00 - PST 2019 Mar Sun>=8 3:00
|
||||
-8:00 - PST 2019 Jan 20 2:00
|
||||
-9:00 US AK%sT
|
||||
Zone America/Yakutat 14:41:05 - LMT 1867 Oct 19 15:12:18
|
||||
-9:18:55 - LMT 1900 Aug 20 12:00
|
||||
|
||||
91
theory.html
91
theory.html
@ -15,7 +15,7 @@
|
||||
<ul>
|
||||
<li><a href="#scope">Scope of the <code><abbr>tz</abbr></code>
|
||||
database</a></li>
|
||||
<li><a href="#naming">Names of timezones</a></li>
|
||||
<li><a href="#naming">Timezone identifiers</a></li>
|
||||
<li><a href="#abbreviations">Time zone abbreviations</a></li>
|
||||
<li><a href="#accuracy">Accuracy of the <code><abbr>tz</abbr></code>
|
||||
database</a></li>
|
||||
@ -107,9 +107,9 @@ It does not always make sense to talk about a timezone's
|
||||
</section>
|
||||
|
||||
<section>
|
||||
<h2 id="naming">Names of timezones</h2>
|
||||
<h2 id="naming">Timezone identifiers</h2>
|
||||
<p>
|
||||
Each timezone has a unique name.
|
||||
Each timezone has a name that uniquely identifies the timezone.
|
||||
Inexperienced users are not expected to select these names unaided.
|
||||
Distributors should provide documentation and/or a simple selection
|
||||
interface that explains each name via a map or via descriptive text like
|
||||
@ -142,10 +142,12 @@ among the following goals:
|
||||
</li>
|
||||
<li>
|
||||
Be robust in the presence of political changes.
|
||||
For example, names of countries are ordinarily not used, to avoid
|
||||
For example, names are typically not tied to countries, to avoid
|
||||
incompatibilities when countries change their name (e.g.,
|
||||
Zaire→Congo) or when locations change countries (e.g., Hong
|
||||
Swaziland→Eswatini) or when locations change countries (e.g., Hong
|
||||
Kong from UK colony to China).
|
||||
There is no requirement that every country or national
|
||||
capital must have a timezone name.
|
||||
</li>
|
||||
<li>
|
||||
Be portable to a wide variety of implementations.
|
||||
@ -214,19 +216,18 @@ in decreasing order of importance:
|
||||
Uninhabited regions like the North Pole and Bouvet Island
|
||||
do not need locations, since local time is not defined there.
|
||||
</li>
|
||||
<li>
|
||||
There should typically be at least one name for each <a
|
||||
href="https://en.wikipedia.org/wiki/ISO_3166-1"><abbr
|
||||
title="International Organization for Standardization">ISO</abbr>
|
||||
3166-1</a> officially assigned two-letter code for an inhabited
|
||||
country or territory.
|
||||
</li>
|
||||
<li>
|
||||
If all the clocks in a timezone have agreed since 1970,
|
||||
do not bother to include more than one timezone
|
||||
even if some of the clocks disagreed before 1970.
|
||||
Otherwise these tables would become annoyingly large.
|
||||
</li>
|
||||
<li>
|
||||
If boundaries between regions are fluid, such as during a war or
|
||||
insurrection, do not bother to create a new timezone merely
|
||||
because of yet another boundary change. This helps prevent table
|
||||
bloat and simplifies maintenance.
|
||||
</li>
|
||||
<li>
|
||||
If a name is ambiguous, use a less ambiguous alternative;
|
||||
e.g., many cities are named San José and Georgetown, so
|
||||
@ -299,29 +300,23 @@ in decreasing order of importance:
|
||||
</ul>
|
||||
|
||||
<p>
|
||||
The file '<code>zone1970.tab</code>' lists geographical locations used
|
||||
to name timezones.
|
||||
It is intended to be an exhaustive list of names for geographic
|
||||
regions as described above; this is a subset of the timezones in the data.
|
||||
Although a '<code>zone1970.tab</code>' location's
|
||||
<a href="https://en.wikipedia.org/wiki/Longitude">longitude</a>
|
||||
corresponds to
|
||||
its <a href="https://en.wikipedia.org/wiki/Local_mean_time">local mean
|
||||
time (<abbr>LMT</abbr>)</a> offset with one hour for every 15°
|
||||
east longitude, this relationship is not exact.
|
||||
Guidelines have evolved with time, and names following old versions of
|
||||
this guideline might not follow the current version. When guidelines
|
||||
have changed, old names continue to be supported. Guideline changes
|
||||
have included the following:
|
||||
</p>
|
||||
|
||||
<p>
|
||||
Older versions of this package used a different naming scheme,
|
||||
and these older names are still supported.
|
||||
<ul>
|
||||
<li>
|
||||
Older versions of this package used a different naming scheme.
|
||||
See the file '<code>backward</code>' for most of these older names
|
||||
(e.g., '<code>US/Eastern</code>' instead of '<code>America/New_York</code>').
|
||||
The other old-fashioned names still supported are
|
||||
'<code>WET</code>', '<code>CET</code>', '<code>MET</code>', and
|
||||
'<code>EET</code>' (see the file '<code>europe</code>').
|
||||
</p>
|
||||
</li>
|
||||
|
||||
<p>
|
||||
<li>
|
||||
Older versions of this package defined legacy names that are
|
||||
incompatible with the first guideline of location names, but which are
|
||||
still supported.
|
||||
@ -332,6 +327,31 @@ Also, the file '<code>backward</code>' defines the legacy names
|
||||
and the file '<code>northamerica</code>' defines the legacy names
|
||||
'<code>EST5EDT</code>', '<code>CST6CDT</code>',
|
||||
'<code>MST7MDT</code>', and '<code>PST8PDT</code>'.
|
||||
</li>
|
||||
|
||||
<li>
|
||||
Older versions of this guideline said that
|
||||
there should typically be at least one name for each <a
|
||||
href="https://en.wikipedia.org/wiki/ISO_3166-1"><abbr
|
||||
title="International Organization for Standardization">ISO</abbr>
|
||||
3166-1</a> officially assigned two-letter code for an inhabited
|
||||
country or territory.
|
||||
This old guideline has been dropped, as it was not needed to handle
|
||||
timestamps correctly and it increased maintenance burden.
|
||||
</li>
|
||||
</ul>
|
||||
|
||||
<p>
|
||||
The file '<code>zone1970.tab</code>' lists geographical locations used
|
||||
to name timezones.
|
||||
It is intended to be an exhaustive list of names for geographic
|
||||
regions as described above; this is a subset of the timezones in the data.
|
||||
Although a '<code>zone1970.tab</code>' location's
|
||||
<a href="https://en.wikipedia.org/wiki/Longitude">longitude</a>
|
||||
corresponds to
|
||||
its <a href="https://en.wikipedia.org/wiki/Local_mean_time">local mean
|
||||
time (<abbr>LMT</abbr>)</a> offset with one hour for every 15°
|
||||
east longitude, this relationship is not exact.
|
||||
</p>
|
||||
|
||||
<p>
|
||||
@ -983,7 +1003,9 @@ an older <code>zic</code>.
|
||||
constrained to be a string containing abbreviations
|
||||
and numeric data as described <a href="#POSIX">above</a>.
|
||||
The file's format is <dfn><abbr>TZif</abbr></dfn>,
|
||||
a timezone information format that contains binary data.
|
||||
a timezone information format that contains binary data; see
|
||||
<a href="https://tools.ietf.org/html/8536">Internet
|
||||
<abbr>RFC</abbr> 8536</a>.
|
||||
The daylight saving time rules to be used for a
|
||||
particular timezone are encoded in the
|
||||
<abbr>TZif</abbr> file; the format of the file allows <abbr>US</abbr>,
|
||||
@ -1166,7 +1188,7 @@ The <code><abbr>tz</abbr></code> code and data supply the following interfaces:
|
||||
<ul>
|
||||
<li>
|
||||
A set of timezone names as per
|
||||
"<a href="#naming">Names of timezones</a>" above.
|
||||
"<a href="#naming">Timezone identifiers</a>" above.
|
||||
</li>
|
||||
<li>
|
||||
Library functions described in "<a href="#functions">Time and date
|
||||
@ -1213,6 +1235,17 @@ For example, users should not rely on particular <abbr>UT</abbr>
|
||||
offsets or abbreviations for timestamps, as data entries are often
|
||||
based on guesswork and these guesses may be corrected or improved.
|
||||
</p>
|
||||
|
||||
<p>
|
||||
Timezone boundaries are not part of the stable interface.
|
||||
For example, even though the <samp>Asia/Bangkok</samp> timezone
|
||||
currently includes Chang Mai, Hanoi, and Phnom Penh, this is not part
|
||||
of the stable interface and the timezone can split at any time.
|
||||
If a calendar application records a future event in some location other
|
||||
than Bangkok by putting "<samp>Asia/Bangkok</samp>" in the event's record,
|
||||
the application should be robust in the presence of timezone splits
|
||||
between now and the future time.
|
||||
</p>
|
||||
</section>
|
||||
|
||||
<section>
|
||||
|
||||
Loading…
Reference in New Issue
Block a user