- tz - lists.iana.org

[PROPOSED] Use GCC 8 for debugging
by Paul Eggert April 30, 2018

April 30, 2018

* Makefile (GCC_DEBUG_FLAGS): Use flags appropriate for GCC 8. --- Makefile | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/Makefile b/Makefile index 3ac1a67..21fa488 100644 --- a/Makefile +++ b/Makefile @@ -236,14 +236,16 @@ 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 -Wdate-time \ + -Wbad-function-cast -Wcast-align=strict -Wdate-time \ -Wdeclaration-after-statement -Wdouble-promotion \ -Wformat=2 -Wformat-overflow=2 -Wformat-signedness -Wformat-truncation \ -Winit-self -Wjump-misses-init -Wlogical-op \ -Wmissing-declarations -Wmissing-prototypes -Wnested-externs \ -Wold-style-definition -Woverlength-strings -Wpointer-arith \ - -Wshadow -Wshift-overflow=2 -Wstrict-prototypes -Wstringop-overflow=5 \ + -Wshadow -Wshift-overflow=2 -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 \ -Wvariadic-macros -Wvla -Wwrite-strings \ -- 2.17.0

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DPRK to revert to UTC+9 from UTC+8:30
by Kang Seonghoon April 30, 2018

April 30, 2018

On 2018-04-29 (+09:00), according to Yoon Young-chan, senior presidental secretary for public relations of South Korea, has announced that North Korea will revert its time zone from UTC+8:30 (PYT; Pyongyang Time) back to UTC+9 (KST; Korea Standard Time), in lieu of the recent Panmunjom Declaration. Yet another time to change tzdata? Source: South and North agreed to unify PYT to KST, Yonhap News http://m.yna.co.kr/kr/contents/?cid=AKR20180429018500001 (no English translation exists right now) -- -- Kang Seonghoon | https://mearie.org/ -- Opinions expressed in this email do not necessarily represent the views of my employer. --

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North Korea timezone to become GMT+9 from May 5 2018
by Phake Nick April 30, 2018

April 30, 2018

The URL to the announcement cannot be directly copied, but you can access www.kcna.kp then select "English" on top right hand corner, and then there will be an article titled "SPA Presidium of DPRK Decides to Reset Pyongyang Time" which talk about the upcoming change in time in North Korea. Media outside North Korea have reported about it too. However, there are no info with respect to exactly which moment in May 5 are they switching their timezone

3 3

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

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[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

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[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

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[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

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[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

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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.

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[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

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