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North Korea to match South Korea's time zone
by Arthur David Olson April 29, 2018

April 29, 2018

A tweet from Jef Poskanzer... https://twitter.com/jef_poskanzer/status/990430801903865856 ...alerted me to North Korea's plan to match South Korea's time zone. An AP item on the matter... https://apnews.com/301adfec088647c1b1cbc69eb4b0949a ...cites South Korean President Moon Jae-in's spokesperson Yoon Young-chan; referring to North Korean leader Kim Jong Un, " Yoon said Kim...revealed plans to re-adjust its current time zone to match the South’s." No word in the AP item on specifics of the plan. @dashdashado

2 1

[PROPOSED] Support zi parsers that mishandle negative DST offsets
by Paul Eggert April 23, 2018

April 23, 2018

This is intended to provide a way to support both clients that require data to have only positive DST offsets, and clients that do not have this restriction. * Makefile (XDST, SDST): New macros. (TZDATA_ZI_DEPS): Add zidst.awk. (DSTDATA_ZI_DEPS): New macro. (all): Depend on fulldata.zi and pdstdata.zi. (fulldata.zi pdstdata.zi): New rule. (tzdata.zi): Use $(XDST)data.zi instead of reading original source. (check_zishrink): Check zidst.awk, too. (clean): Remove all *.zi files, not just tzdata.zi. * NEWS, europe: Mention this. * zidst.awk: New file. --- Makefile | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++++----------- NEWS | 30 ++++++++++++++++++++++++++++++ europe | 39 ++++++++++++++++++++++----------------- zidst.awk | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 154 insertions(+), 28 deletions(-) create mode 100644 zidst.awk diff --git a/Makefile b/Makefile index 8c84cd9..92ddb80 100644 --- a/Makefile +++ b/Makefile @@ -10,6 +10,26 @@ VERSION= unknown # Email address for bug reports. BUGEMAIL= tz(a)iana.org +# To install the full data, which can contain daylight saving time +# offsets that are negative (relative to standard time), use +# XDST= full +# To install data containing only positive daylight saving time +# offsets, but otherwise as close to the full data as practical, use +# XDST= pdst +XDST= pdst +# Parsers requiring DST offsets to be positive should use the file +# pdstdata.zi, which contains almost all the data of 'africa' etc., +# except with positive DST offsets. This works around a problem that +# was discovered in January 2018 with negative DST in tests for ICU +# and OpenJDK. See: +# https://mm.icann.org/pipermail/tz/2018-January/025825.html +# https://mm.icann.org/pipermail/tz/2018-January/025822.html +# Currently the 'africa' etc. files use pdst form if comments are +# ignored, to ease transition for parsers that do not support +# negative DST offsets. This is intended to change to full form at +# some point, so that full-featured zi parsers that use the 'africa' +# files will get the full data without changing anything. + # Change the line below for your time zone (after finding the zone you want in # the time zone files, or adding it to a time zone file). # Alternately, if you discover you've got the wrong time zone, you can just @@ -463,7 +483,8 @@ TDATA= $(YDATA) $(NDATA) $(BACKWARD) ZONETABLES= zone1970.tab zone.tab TABDATA= iso3166.tab $(TZDATA_TEXT) $(ZONETABLES) LEAP_DEPS= leapseconds.awk leap-seconds.list -TZDATA_ZI_DEPS= zishrink.awk version $(TDATA) $(PACKRATDATA) +TZDATA_ZI_DEPS= zidst.awk zishrink.awk version $(TDATA) $(PACKRATDATA) +DSTDATA_ZI_DEPS= zidst.awk $(TDATA) $(PACKRATDATA) DATA= $(TDATA_TO_CHECK) backzone iso3166.tab leap-seconds.list \ leapseconds yearistype.sh $(ZONETABLES) AWK_SCRIPTS= checklinks.awk checktab.awk leapseconds.awk zishrink.awk @@ -500,7 +521,8 @@ VERSION_DEPS= \ SHELL= /bin/sh -all: tzselect yearistype zic zdump libtz.a $(TABDATA) +all: tzselect yearistype zic zdump libtz.a $(TABDATA) \ + fulldata.zi pdstdata.zi ALL: all date $(ENCHILADA) @@ -535,11 +557,15 @@ version: $(VERSION_DEPS) printf '%s\n' "$$V" >$@.out mv $@.out $@ -# This file can be tailored by setting BACKWARD, PACKRATDATA, etc. -tzdata.zi: $(TZDATA_ZI_DEPS) +# These files can be tailored by setting BACKWARD, PACKRATDATA, etc. +fulldata.zi pdstdata.zi: $(DSTDATA_ZI_DEPS) + $(AWK) -v outfile='$@' -f zidst.awk $(TDATA) $(PACKRATDATA) \ + >$@.out + mv $@.out $@ +tzdata.zi: $(XDST)data.zi version version=`sed 1q version` && \ LC_ALL=C $(AWK) -v version="$$version" -f zishrink.awk \ - $(TDATA) $(PACKRATDATA) >$@.out + $(XDST)data.zi >$@.out mv $@.out $@ version.h: version @@ -721,17 +747,32 @@ check_tzs: $(TZS) $(TZS_NEW) check_web: tz-how-to.html $(VALIDATE_ENV) $(VALIDATE) $(VALIDATE_FLAGS) tz-how-to.html -# Check that tzdata.zi generates the same binary data that its sources do. -check_zishrink: tzdata.zi zic leapseconds $(PACKRATDATA) $(TDATA) +# The format of the source files, either full or pdst. +# Currently they are in pdst format, but this is expected to change. +SDST = pdst + +# Check that zishrink.awk does not alter the data, and that zidst.awk +# preserves $(SDST) data. +check_zishrink: zic leapseconds $(PACKRATDATA) $(TDATA) \ + $(XDST)data.zi tzdata.zi for type in posix right; do \ - mkdir -p time_t.dir/$$type time_t.dir/$$type-shrunk && \ + mkdir -p time_t.dir/$$type time_t.dir/$$type-$(SDST) \ + time_t.dir/$$type-shrunk && \ case $$type in \ right) leap='-L leapseconds';; \ *) leap=;; \ esac && \ - $(ZIC) $$leap -d time_t.dir/$$type $(TDATA) && \ - $(AWK) '/^Rule/' $(TDATA) | \ + $(ZIC) $$leap -d time_t.dir/$$type $(XDST)data.zi && \ + $(AWK) '/^Rule/' $(XDST)data.zi | \ $(ZIC) $$leap -d time_t.dir/$$type - $(PACKRATDATA) && \ + case $(XDST) in \ + $(SDST)) \ + $(ZIC) $$leap -d time_t.dir/$$type-$(SDST) $(TDATA) && \ + $(AWK) '/^Rule/' $(TDATA) | \ + $(ZIC) $$leap -d time_t.dir/$$type-$(SDST) \ + $(XDST)data.zi && \ + diff -r time_t.dir/$$type time_t.dir/$$type-$(SDST);; \ + esac && \ $(ZIC) $$leap -d time_t.dir/$$type-shrunk tzdata.zi && \ diff -r time_t.dir/$$type time_t.dir/$$type-shrunk || exit; \ done @@ -741,7 +782,7 @@ clean_misc: rm -f core *.o *.out \ date tzselect version.h zdump zic yearistype libtz.a clean: clean_misc - rm -fr *.dir tzdata.zi tzdb-*/ $(TZS_NEW) + rm -fr *.dir *.zi tzdb-*/ $(TZS_NEW) maintainer-clean: clean @echo 'This command is intended for maintainers to use; it' diff --git a/NEWS b/NEWS index 4f763c0..c455f3c 100644 --- a/NEWS +++ b/NEWS @@ -2,6 +2,36 @@ News for the tz database Unreleased, experimental changes + Briefly: + Support zi parsers that mishandle negative DST offsets + + Changes to build procedure + + The new XDST macro in the Makefile lets the installer choose + XDST=full, which allows arbitrary DST offsets in the data, or + XDST=pdst, which allows only positive DST offsets. Choosing + XDST=full is arguably more correct for Ireland, which observes + Irish Standard Time (IST, UTC+01) in summer and GMT (UTC) in + winter. Choosing XDST=pdst is better for zoneinfo parsers that do + not work well with negative DST offsets, notably OpenJDK+CLDR. + On platforms using tzcode or similar APIs, XDST should not affect + any behavior other than that depending on the tm_isdst flag. + + For now this change does not affect client-visible behavior by + default, as the Makefile defaults to XDST=pdst and uncommented + parts of the data source files contain only pdst-format data. + After a bit of time for testing, XDST=full and full-format source + files are planned to become the default, so that parsers that + support negative DST offsets can get full data without changing + their build procedures. Parsers requiring positive DST offsets + should use the new file pdstdata.zi instead of tzdata.zi or the + source files 'africa' etc.: pdstdata.zi is pdst-compatible, it is + automatically built from the data source files, and it will + continue to be pdst-compatible regardless of XDST. To get + full-format data now, use the new file fulldata.zi, which will + continue to be full-format regardless of XDST. To get the format + selected by XDST, use tzdata.zi. + Changes to code The code is a bit more portable to MS-Windows. (Thanks to Manuela diff --git a/europe b/europe index 6c1ccbe..5aeda33 100644 --- a/europe +++ b/europe @@ -508,11 +508,27 @@ Link Europe/London Europe/Jersey Link Europe/London Europe/Guernsey Link Europe/London Europe/Isle_of_Man -# From Paul Eggert (2018-01-19): +# From Paul Eggert (2018-01-30): +# In January 2018 we discovered that the negative DST offsets in the +# Eire rules cause problems with tests for ICU: +# https://mm.icann.org/pipermail/tz/2018-January/025825.html +# and with tests for OpenJDK: +# https://mm.icann.org/pipermail/tz/2018-January/025822.html +# To work around this problem, zidst.awk translates the following data +# lines into two forms. First, fulldata.zi contains the full data, +# which includes negative DST offsets. Second, pdstdata.zi uses a +# traditional approximation for Irish time stamps after 1971-10-31 +# 02:00 UTC; although this approximation has tm_isdst flags that are +# the reverse of the full data, its UTC offsets are correct and this +# suffices for ICU and OpenJDK. Although this source file currently +# has pdstdata.zi lines active and fulldata.zi lines commented out, +# this is intended to change in the near future and downstream code +# should not rely on it. +# # The following is like GB-Eire and EU, except with standard time in # summer and negative daylight saving time in winter. -# Although currently commented out, this will need to become uncommented -# once the ICU/OpenJDK workaround is removed; see below. +# This rule set is active in fulldata.zi and is commented out in +# pdstdata.zi. # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S #Rule Eire 1971 only - Oct 31 2:00u -1:00 GMT #Rule Eire 1972 1980 - Mar Sun>=16 2:00u 0 IST @@ -533,24 +549,13 @@ Zone Europe/Dublin -0:25:00 - LMT 1880 Aug 2 0:00 1:00 IST 1947 Nov 2 2:00s 0:00 - GMT 1948 Apr 18 2:00s 0:00 GB-Eire GMT/IST 1968 Oct 27 -# From Paul Eggert (2018-01-18): -# The next line should look like this: +# The next line is active in fulldata.zi and commented out in pdstdata.zi. # 1:00 Eire IST/GMT -# However, in January 2018 we discovered that the Eire rules cause -# problems with tests for ICU: -# https://mm.icann.org/pipermail/tz/2018-January/025825.html -# and with tests for OpenJDK: -# https://mm.icann.org/pipermail/tz/2018-January/025822.html -# To work around this problem, use a traditional approximation for -# time stamps after 1971-10-31 02:00 UTC, to give ICU and OpenJDK -# developers breathing room to fix bugs. This approximation has -# correct UTC offsets, but results in tm_isdst flags are the reverse -# of what they should be. This workaround is temporary and should be -# removed reasonably soon. +# These three lines are active in pdstdata.zi and commented out in +# fulldata.zi. 1:00 - IST 1971 Oct 31 2:00u 0:00 GB-Eire GMT/IST 1996 0:00 EU GMT/IST -# End of workaround for ICU and OpenJDK bugs. ############################################################################### diff --git a/zidst.awk b/zidst.awk new file mode 100644 index 0000000..7885e9a --- /dev/null +++ b/zidst.awk @@ -0,0 +1,50 @@ +# Convert tzdata source into full or positive-DST form + +# Contributed by Paul Eggert. This file is in the public domain. + +# This is not a general-purpose converter; it is designed for current tzdata. +# +# When converting to full form, the output can use negative DST offsets. +# +# When converting to positive-DST form, the output uses only positive +# DST offsets. The idea is for the output data to simulate the +# behavior of the input data as best it can within the constraints of +# positive DST offsets. +# +# In the input, lines requiring the full format are commented #[full] +# and the positive DST near-equivalents are commented #[pdst]. + +BEGIN { + dst_type["full"] = 1 + dst_type["pdst"] = 1 + + # The command line should set OUTFILE to the name of the output file, + # which should start with either "full" or "pdst". + todst = substr(outfile, 1, 4) + if (!dst_type[todst]) exit 1 +} + +/^Zone/ { zone = $2 } + +{ + in_comment = /^#/ + + # Test whether this line should differ between the full and the pdst versions. + Rule_Eire = /^#?Rule[\t ]+Eire[\t ]/ + Zone_Dublin_post_1968 \ + = (zone == "Europe/Dublin" && /^#?[\t ]+[01]:00[\t ]/ \ + && (!$(in_comment + 4) || 1968 < $(in_comment + 4))) + + # If so, uncomment the desired version and comment out the undesired one. + if (Rule_Eire || Zone_Dublin_post_1968) { + if ((Rule_Eire \ + || (Zone_Dublin_post_1968 && $(in_comment + 3) == "IST/GMT")) \ + == (todst == "full")) { + sub(/^#/, "") + } else if (/^[^#]/) { + sub(/^/, "#") + } + } +} + +{ print } -- 2.14.3

7 14

[PATCH] Fix ziguard.awk Namibia invalid assumption
by Paul Eggert April 22, 2018

April 22, 2018

* ziguard.awk: Don’t assume input is in rearguard format. --- ziguard.awk | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/ziguard.awk b/ziguard.awk index 7cdceab..dbe64d6 100644 --- a/ziguard.awk +++ b/ziguard.awk @@ -63,7 +63,11 @@ outfile != "main.zi" { || (1994 <= $(in_comment + 4) && $(in_comment + 4) <= 2017) \ || in_comment + 3 == NF)) if (Rule_Namibia || Zone_using_Namibia_rule) { - if (in_comment == vanguard) { + if ((Rule_Namibia \ + ? ($(in_comment + 9) ~ /^-/ \ + || ($(in_comment + 9) == 0 && $(in_comment + 10) == "CAT")) \ + : $(in_comment + 1) == "2:00" && $(in_comment + 2) == "Namibia") \ + == vanguard) { uncomment = in_comment } else { comment_out = !in_comment -- 2.14.3

1 0

[PROPOSED] Update and/or clean up POSIX version info
by Paul Eggert April 15, 2018

April 15, 2018

--- asctime.c | 12 +++--------- localtime.c | 7 +++---- theory.html | 2 +- 3 files changed, 7 insertions(+), 14 deletions(-) diff --git a/asctime.c b/asctime.c index a55f785..56c54b3 100644 --- a/asctime.c +++ b/asctime.c @@ -1,3 +1,5 @@ +/* asctime and asctime_r a la POSIX and ISO C, except pad years before 1000. */ + /* ** This file is in the public domain, so clarified as of ** 1996-06-05 by Arthur David Olson. @@ -29,7 +31,7 @@ ** leading zeroes to get the newline in the traditional place. ** The -4 ensures that we get four characters of output even if ** we call a strftime variant that produces fewer characters for some years. -** The ISO C 1999 and POSIX 1003.1-2004 standards prohibit padding the year, +** The ISO C and POSIX standards prohibit padding the year, ** but many implementations pad anyway; most likely the standards are buggy. */ #ifdef __GNUC__ @@ -64,10 +66,6 @@ static char buf_asctime[MAX_ASCTIME_BUF_SIZE]; -/* -** A la ISO/IEC 9945-1, ANSI/IEEE Std 1003.1, 2004 Edition. -*/ - char * asctime_r(register const struct tm *timeptr, char *buf) { @@ -117,10 +115,6 @@ asctime_r(register const struct tm *timeptr, char *buf) } } -/* -** A la ISO/IEC 9945-1, ANSI/IEEE Std 1003.1, 2004 Edition. -*/ - char * asctime(register const struct tm *timeptr) { diff --git a/localtime.c b/localtime.c index b6b82bb..5b5a5b1 100644 --- a/localtime.c +++ b/localtime.c @@ -88,9 +88,8 @@ static const char gmt[] = "GMT"; /* ** The DST rules to use if TZ has no rules and we can't load TZDEFRULES. ** Default to US rules as of 2017-05-07. -** POSIX 1003.1 section 8.1.1 says that the default DST rules are -** implementation dependent; for historical reasons, US rules are a -** common default. +** POSIX does not specify the default DST rules; +** for historical reasons, US rules are a common default. */ #ifndef TZDEFRULESTRING #define TZDEFRULESTRING ",M3.2.0,M11.1.0" @@ -2211,7 +2210,7 @@ timeoff(struct tm *tmp, long offset) #ifdef STD_INSPIRED /* -** IEEE Std 1003.1-1988 (POSIX) legislates that 536457599 +** IEEE Std 1003.1 (POSIX) says that 536457599 ** shall correspond to "Wed Dec 31 23:59:59 UTC 1986", which ** is not the case if we are accounting for leap seconds. ** So, we provide the following conversion routines for use diff --git a/theory.html b/theory.html index b27b212..fc2102b 100644 --- a/theory.html +++ b/theory.html @@ -68,7 +68,7 @@ standard for <a href="https://en.wikipedia.org/wiki/Unix">UNIX</a>-like systems. As of this writing, the current edition of POSIX is: <a href="http://pubs.opengroup.org/onlinepubs/9699919799/"> The Open -Group Base Specifications Issue 7</a>, IEEE Std 1003.1-2008, 2016 +Group Base Specifications Issue 7</a>, IEEE Std 1003.1-2017, 2018 Edition. Because the database's scope encompasses real-world changes to civil timekeeping, its model for describing time is more complex than the -- 2.7.4

1 0

[PROPOSED] * europe: Adjust to kalendar.beda.cz correction.
by Paul Eggert April 15, 2018

April 15, 2018

--- europe | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/europe b/europe index 160be9f..6b97fd0 100644 --- a/europe +++ b/europe @@ -971,14 +971,9 @@ Zone Europe/Sofia 1:33:16 - LMT 1880 # Czech Republic / Czechia # -# From Paul Eggert (2018-04-14): -# The source for Czech data is: Kdy začíná a končí letní čas. +# From Paul Eggert (2018-04-15): +# The source for Czech data is: Kdy začíná a končí letní čas. 2018-04-15. # https://kalendar.beda.cz/kdy-zacina-a-konci-letni-cas -# with one correction, taken from: -# Sbírka zákonů a nařízení republiky Československé, částka 92/1946. -# http://ftp.aspi.cz/opispdf/1946/092-1946.pdf -# which says that the winter time (negative DST) starting 1946-12-01 -# was a switch from 03:00 to 02:00 (not from 02:00 to 01:00). # We know of no English-language name for historical Czech winter time; # abbreviate it as "GMT", as it happened to be GMT. # -- 2.14.3

1 0

start of 1946 winter time in "Kdy začíná a končí letní čas"
by Paul Eggert April 14, 2018

April 14, 2018

I recently proposed some tz database changes for Prague; see <https://en.wikipedia.org/wiki/Tz_database> and <https://mm.icann.org/pipermail/tz/2018-April/026415.html>. I used your web page <https://kalendar.beda.cz/kdy-zacina-a-konci-letni-cas> as the main source for these fixes; thank you! I noticed what appears to be a typographical error in your web page. It says: 1946-7 zimní čas 1. prosinec (2:00) 23. únor (2:00) However, the primary source <http://ftp.aspi.cz/opispdf/1946/092-1946.pdf> says: "§1. Počátek zimního času v roce 1946 se určuje na den 1. prosince 1946 o třetí hodiné ranní středoevropského času a provede se posunutím hodinových ručiček na druhou hodinu." Google Translate suggests this means the transition was December 1 at 03:00, not December 1 at 02:00. That is, the clock was 03:00 before the transition, and 02:00 afterwards. The attached patch contains a proposed fix to kalendar.beda.cz. I am CC:ing this to the time zone mailing list to give them a heads-up as to why I made this change in the tz database.

1 0

[PROPOSED 1/2] Czechs had negative DST in 1946/7
by Paul Eggert April 14, 2018

April 14, 2018

* NEWS: Document this. * europe (Czech): Adjust 1945 transition dates to match new source. (Europe/Prague): Likewise. Add negative DST in 1946/7. * tz-link.html: Link to kalendar.beda.cz. * ziguard.awk: Adjust to Czech changes. --- NEWS | 6 ++++++ europe | 24 +++++++++++++++++++++--- tz-link.html | 4 ++++ ziguard.awk | 10 ++++++++++ 4 files changed, 41 insertions(+), 3 deletions(-) diff --git a/NEWS b/NEWS index 17492b3..13652fc 100644 --- a/NEWS +++ b/NEWS @@ -29,6 +29,12 @@ Unreleased, experimental changes format; in rearguard and main format, the tm_isdst flag is still zero in winter and nonzero in summer. + In 1946/7 Czechoslovakia also observed negative DST in winter. + The full effect of this change is only in vanguard format; in + rearguard and main formats, it is modeled as plain GMT without + daylight saving. Also, the dates of some 1944/5 DST transitions + in Czechoslovakia have been changed. + Release 2018d - 2018-03-22 07:05:46 -0700 diff --git a/europe b/europe index 20eb4e8..5edb686 100644 --- a/europe +++ b/europe @@ -970,9 +970,21 @@ Zone Europe/Sofia 1:33:16 - LMT 1880 # Please see the 'asia' file for Asia/Nicosia. # Czech Republic / Czechia +# +# From Paul Eggert (2018-04-14): +# The source for Czech data is: Kdy začíná a končí letní čas. +# https://kalendar.beda.cz/kdy-zacina-a-konci-letni-cas +# with one correction, taken from: +# Sbírka zákonů a nařízení republiky Československé, částka 92/1946. +# http://ftp.aspi.cz/opispdf/1946/092-1946.pdf +# which says that the winter time (negative DST) starting 1946-12-01 +# was a switch from 03:00 to 02:00 (not from 02:00 to 01:00). +# We know of no English-language name for historical Czech winter time; +# abbreviate it as "GMT", as it happened to be GMT. +# # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S -Rule Czech 1945 only - Apr 8 2:00s 1:00 S -Rule Czech 1945 only - Nov 18 2:00s 0 - +Rule Czech 1945 only - Apr Mon>=1 2:00s 1:00 S +Rule Czech 1945 only - Oct 1 2:00s 0 - Rule Czech 1946 only - May 6 2:00s 1:00 S Rule Czech 1946 1949 - Oct Sun>=1 2:00s 0 - Rule Czech 1947 only - Apr 20 2:00s 1:00 S @@ -981,7 +993,13 @@ Rule Czech 1949 only - Apr 9 2:00s 1:00 S # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Europe/Prague 0:57:44 - LMT 1850 0:57:44 - PMT 1891 Oct # Prague Mean Time - 1:00 C-Eur CE%sT 1944 Sep 17 2:00s + 1:00 C-Eur CE%sT 1945 May 9 + 1:00 Czech CE%sT 1946 Dec 1 3:00 +# Vanguard section, for zic and other parsers that support negative DST. +# 1:00 -1:00 GMT 1947 Feb 23 2:00 +# Rearguard section, for parsers that do not support negative DST. + 0:00 - GMT 1947 Feb 23 2:00 +# End of rearguard section. 1:00 Czech CE%sT 1979 1:00 EU CE%sT # Use Europe/Prague also for Slovakia. diff --git a/tz-link.html b/tz-link.html index 6700c7f..13a824d 100644 --- a/tz-link.html +++ b/tz-link.html @@ -728,6 +728,10 @@ zones & daylight saving time</a>.</dd> <dd>The Hydrographic and Oceanographic Service of the Chilean Navy publishes a <a href="http://www.horaoficial.cl/historia_hora.html" hreflang="es">history of Chile's official time (in Spanish)</a>.</dd> +<dt>Czech Republic</dt> +<dd><a href="https://kalendar.beda.cz/kdy-zacina-a-konci-letni-cas" +hreflang="cs">When daylight saving time starts and ends (in Czech)</a> +summarizes and cites historical DST regulations.</dd> <dt>Germany</dt> <dd>The National Institute for Science and Technology maintains the <a href="https://www.ptb.de/cms/en/fachabteilungen/abt4/fb-44/ag-441/realisation-of-…">Realisation diff --git a/ziguard.awk b/ziguard.awk index 5bfaebb..7cdceab 100644 --- a/ziguard.awk +++ b/ziguard.awk @@ -28,6 +28,16 @@ outfile != "main.zi" { in_comment = /^#/ uncomment = comment_out = 0 + # If the line should differ due to Czechoslovakia using negative SAVE values, + # uncomment the desired version and comment out the undesired one. + if (zone == "Europe/Prague" && /1947 Feb 23/) { + if (($(in_comment + 2) != "-") == vanguard) { + uncomment = in_comment + } else { + comment_out = !in_comment + } + } + # If this line should differ due to Ireland using negative SAVE values, # uncomment the desired version and comment out the undesired one. Rule_Eire = /^#?Rule[\t ]+Eire[\t ]/ -- 2.7.4

1 1

[PROPOSED] * europe: Remove "exactly" from comment; it was not exactly right.
by Paul Eggert April 14, 2018

April 14, 2018

--- europe | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/europe b/europe index 3f092a4..20eb4e8 100644 --- a/europe +++ b/europe @@ -2016,7 +2016,7 @@ Rule Neth 1938 1939 - May 15 2:00s 1:00 S Rule Neth 1945 only - Apr 2 2:00s 1:00 S Rule Neth 1945 only - Sep 16 2:00s 0 - # -# Amsterdam Mean Time was +00:19:32.13 exactly, but the .13 is omitted +# Amsterdam Mean Time was +00:19:32.13, but the .13 is omitted # below because the current format requires GMTOFF to be an integer. # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Europe/Amsterdam 0:19:32 - LMT 1835 -- 2.14.3

1 0

[PROPOSED] Namibia was on DST until 2017-10-24
by Paul Eggert April 9, 2018

April 9, 2018

While we're at it, use negative DST offsets in vanguard format, since Namibia (like Ireland) used negative DST in winter. * NEWS, africa (Namibia, Africa/Windhoek), ziguard.awk: Implement this. --- NEWS | 10 ++++++++++ africa | 19 +++++++++++++++++-- ziguard.awk | 28 +++++++++++++++++++++++++--- 3 files changed, 52 insertions(+), 5 deletions(-) diff --git a/NEWS b/NEWS index 0297fd8..3bbb829 100644 --- a/NEWS +++ b/NEWS @@ -1,5 +1,15 @@ News for the tz database +Unreleased, experimental changes + + Changes to past time stamps + + For Namibia's transition from +01/+02 to plain +02, change the + transition date from 2017-09-03 at 03:00 to 2017-10-24 at 00:00. + This does not affect UTC offsets, only whether a DST regime was + in place. + + Release 2018d - 2018-03-22 07:05:46 -0700 Briefly: diff --git a/africa b/africa index 2f7217a..e564906 100644 --- a/africa +++ b/africa @@ -992,9 +992,20 @@ Link Africa/Maputo Africa/Lusaka # Zambia # the same time they would normally start DST, the first Sunday in September: # https://www.timeanddate.com/news/time/namibia-new-time-zone.html +# From Paul Eggert (2017-04-05): +# The official date of the time zone change was 2017-10-24. See: +# http://www.lac.org.na/laws/annoSTAT/Namibian%20Time%20Act%209%20of%202017.p… + # RULE NAME FROM TO TYPE IN ON AT SAVE LETTER/S +# The following has standard time in summer and negative daylight +# saving time in winter. It is for when negative SAVE values are used. +# For more about this, see the comments in 'europe' for Rule Eire. +#Rule Namibia 1994 only - Mar 21 0:00 -1:00 +01 +#Rule Namibia 1994 2017 - Sep Sun>=1 2:00 0 CAT +#Rule Namibia 1995 2017 - Apr Sun>=1 2:00 -1:00 +01 +# The following is for when SAVE values are always nonnegative. Rule Namibia 1994 only - Mar 21 0:00 0 - -Rule Namibia 1994 2016 - Sep Sun>=1 2:00 1:00 S +Rule Namibia 1994 2017 - Sep Sun>=1 2:00 1:00 S Rule Namibia 1995 2017 - Apr Sun>=1 2:00 0 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Africa/Windhoek 1:08:24 - LMT 1892 Feb 8 @@ -1003,7 +1014,11 @@ Zone Africa/Windhoek 1:08:24 - LMT 1892 Feb 8 2:00 1:00 SAST 1943 Mar 21 2:00 2:00 - SAST 1990 Mar 21 # independence 2:00 - CAT 1994 Mar 21 0:00 - 1:00 Namibia WA%sT 2017 Sep 3 2:00 +# The next line is for when negative SAVE values are used. +# 2:00 Namibia %s 2017 Oct 24 +# The next line is for when SAVE values are always nonnegative. + 1:00 Namibia WA%sT 2017 Oct 24 +# End of daylight saving. 2:00 - CAT # Niger diff --git a/ziguard.awk b/ziguard.awk index 6da3691..710b630 100644 --- a/ziguard.awk +++ b/ziguard.awk @@ -26,6 +26,7 @@ BEGIN { outfile != "main.zi" { in_comment = /^#/ + uncomment = comment_out = 0 # If this line should differ due to Ireland using negative SAVE values, # uncomment the desired version and comment out the undesired one. @@ -37,11 +38,32 @@ outfile != "main.zi" { if ((Rule_Eire \ || (Zone_Dublin_post_1968 && $(in_comment + 3) == "IST/GMT")) \ == vanguard) { - sub(/^#/, "") - } else if (/^[^#]/) { - sub(/^/, "#") + uncomment = in_comment + } else { + comment_out = !in_comment } } + + # If this line should differ due to Namibia using negative SAVE values, + # uncomment the desired version and comment out the undesired one. + Rule_Namibia = /^#?Rule[\t ]+Namibia[\t ]/ + Zone_using_Namibia_rule \ + = (zone == "Africa/Windhoek" && /^#?[\t ]+[12]:00[\t ]/ \ + && $(in_comment + 2) == "Namibia") + if (Rule_Namibia || Zone_using_Namibia_rule) { + if (in_comment == vanguard) { + uncomment = in_comment + } else { + comment_out = !in_comment + } + } + + if (uncomment) { + sub(/^#/, "") + } + if (comment_out) { + sub(/^/, "#") + } } # If a Link line is followed by a Zone line for the same data, comment -- 2.14.3

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[PATCH] * Makefile, strftime.c, zic.8: alternate -> alternative
by Paul Eggert April 9, 2018

April 9, 2018

--- Makefile | 4 ++-- strftime.c | 2 +- zic.8 | 8 ++++---- 3 files changed, 7 insertions(+), 7 deletions(-) diff --git a/Makefile b/Makefile index 23599ce..2365d7c 100644 --- a/Makefile +++ b/Makefile @@ -21,7 +21,7 @@ DATAFORM= main # Change the line below for your time zone (after finding the zone you want in # the time zone files, or adding it to a time zone file). -# Alternately, if you discover you've got the wrong time zone, you can just +# Alternatively, if you discover you've got the wrong time zone, you can just # zic -l rightzone # to correct things. # Use the command @@ -38,7 +38,7 @@ LOCALTIME= GMT # template file are used to determine "spring forward" and "fall back" days and # times; the environment variable itself specifies UT offsets of standard and # daylight saving time. -# Alternately, if you discover you've got the wrong time zone, you can just +# Alternatively, if you discover you've got the wrong time zone, you can just # zic -p rightzone # to correct things. # Use the command diff --git a/strftime.c b/strftime.c index 6da3fb9..e855890 100644 --- a/strftime.c +++ b/strftime.c @@ -224,7 +224,7 @@ label: ** %Ec %EC %Ex %EX %Ey %EY ** %Od %oe %OH %OI %Om %OM ** %OS %Ou %OU %OV %Ow %OW %Oy - ** are supposed to provide alternate + ** are supposed to provide alternative ** representations. */ goto label; diff --git a/zic.8 b/zic.8 index 4251868..97644ac 100644 --- a/zic.8 +++ b/zic.8 @@ -372,7 +372,7 @@ begin the field with a minus sign if time must be subtracted from UT. .TP .B RULES The name of the rules that apply in the time zone or, -alternately, an amount of time to add to local standard time. +alternatively, an amount of time to add to local standard time. If this field is .B \*- then standard time always applies in the time zone. @@ -386,7 +386,7 @@ The pair of characters is used to show where the .q "variable part" of the time zone abbreviation goes. -Alternately, a format can use the pair of characters +Alternatively, a format can use the pair of characters .B %z to stand for the UT offset in the form .RI \(+- hh , @@ -399,7 +399,7 @@ using the shortest form that does not lose information, where and .I ss are the hours, minutes, and seconds east (+) or west (\(mi) of UT. -Alternately, +Alternatively, a slash (/) separates standard and daylight abbreviations. To conform to POSIX, a time zone abbreviation should contain only @@ -455,7 +455,7 @@ field should appear as the field in some zone line. The .B LINK-NAME -field is used as an alternate name for that zone; +field is used as an alternative name for that zone; it has the same syntax as a zone line's .B NAME field. -- 2.7.4

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