- tz - lists.iana.org

[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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[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

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[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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[PROPOSED 1/2] * .gitignore: Ignore .patch and .tzs files.
by Paul Eggert April 8, 2018

April 8, 2018

--- .gitignore | 2 ++ 1 file changed, 2 insertions(+) diff --git a/.gitignore b/.gitignore index bc6fc25..1e62d11 100644 --- a/.gitignore +++ b/.gitignore @@ -3,8 +3,10 @@ *.a *.asc *.o +*.patch *.tar.* *.txt +*.tzs *.zi *~ ChangeLog -- 2.14.3

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[PROPOSED] Mention Zone names with two slashes
by Paul Eggert April 6, 2018

April 6, 2018

* theory.html: Mention that some zone names have two slashes, e.g., America/Indiana/Petersburg. Use past tense for Mars Pathfinder. Avoid contractions. Use full zone names in examples and omit no-longer-needed quotes. Add URLs and fix typos. --- theory.html | 105 +++++++++++++++++++++++++++++++++++------------------------- 1 file changed, 61 insertions(+), 44 deletions(-) diff --git a/theory.html b/theory.html index 596b32c..ba57653 100644 --- a/theory.html +++ b/theory.html @@ -53,7 +53,7 @@ However, the database is not designed for and does not suffice for applications requiring accurate handling of all past times everywhere, as it would take far too much effort and guesswork to record all details of pre-1970 civil timekeeping. -Athough some information outside the scope of the database is +Although some information outside the scope of the database is collected in a file <code>backzone</code> that is distributed along with the database proper, this file is less reliable and does not necessarily follow database guidelines. @@ -79,7 +79,7 @@ flip back and forth between two alternatives, and the rules themselves can change at times. Whether and when a <code><abbr>tz</abbr></code> region changes its clock, and even the region's notional base offset from UTC, are variable. -It doesn't even really make sense to talk about a region's +It does not always make sense to talk about a region's "base offset", since it is not necessarily a single number. </p> @@ -92,8 +92,8 @@ Each <code><abbr>tz</abbr></code> region has a unique name that corresponds to a set of time zone rules. Inexperienced users are not expected to select these names unaided. Distributors should provide documentation and/or a simple selection -interface that explains the names; for one example, see the 'tzselect' -program in the <code><abbr>tz</abbr></code> code. +interface that explains the names; for one example, see the +<code>tzselect</code> program in the <code><abbr>tz</abbr></code> code. The <a href="http://cldr.unicode.org/">Unicode Common Locale Data Repository</a> contains data that may be useful for other selection interfaces. @@ -137,6 +137,9 @@ region. North and South America share the same area, '<code>America</code>'. Typical names are '<code>Africa/Cairo</code>', '<code>America/New_York</code>', and '<code>Pacific/Honolulu</code>'. +Some names are further qualified to help avoid confusion; for example, +'<code>America/Indiana/Petersburg</code>' distinguishes Petersburg, +Indiana from other Petersburgs in America. </p> <p> @@ -159,7 +162,8 @@ in decreasing order of importance: <code>TZ</code> strings</a>. A file name component must not exceed 14 characters or start with '<code>-</code>'. - E.g., prefer '<code>Brunei</code>' to '<code>Bandar_Seri_Begawan</code>'. + E.g., prefer <code>Asia/Brunei</code> to + <code>Asia/Bandar_Seri_Begawan</code>. Exceptions: see the discussion of legacy names below. </li> <li> @@ -177,8 +181,8 @@ in decreasing order of importance: name <var>AB</var> (ignoring case), then <var>B</var> must not start with '<code>/</code>', as a regular file cannot have the same name as a directory in POSIX. - For example, '<code>America/New_York</code>' precludes - '<code>America/New_York/Bronx</code>'. + For example, <code>America/New_York</code> precludes + <code>America/New_York/Bronx</code>. </li> <li> Uninhabited regions like the North Pole and Bouvet Island @@ -193,50 +197,56 @@ in decreasing order of importance: </li> <li> If all the clocks in a region have agreed since 1970, - don't bother to include more than one location + do not bother to include more than one location even if subregions' clocks disagreed before 1970. Otherwise these tables would become annoyingly large. </li> <li> If a name is ambiguous, use a less ambiguous alternative; e.g., many cities are named San José and Georgetown, so - prefer '<code>Costa_Rica</code>' to '<code>San_Jose</code>' and - '<code>Guyana</code>' to '<code>Georgetown</code>'. + prefer <code>America/Costa_Rica</code> to + <code>America/San_Jose</code> and <code>America/Guyana</code> + to <code>America/Georgetown</code>. </li> <li> Keep locations compact. Use cities or small islands, not countries or regions, so that any future changes do not split individual locations into different <code><abbr>tz</abbr></code> regions. - E.g., prefer '<code>Paris</code>' to '<code>France</code>', since + E.g., prefer <code>Europe/Paris</code> to <code>Europe/France</code>, + since <a href="https://en.wikipedia.org/wiki/Time_in_France#History">France has had multiple time zones</a>. </li> <li> - Use mainstream English spelling, e.g., prefer '<code>Rome</code>' - to '<code>Roma</code>', and prefer '<code>Athens</code>' to the - Greek '<code>Αθήνα</code>' or the Romanized '<code>Athína</code>'. + Use mainstream English spelling, e.g., prefer + <code>Europe/Rome</code> to <code>Europe/Roma</code>, and + prefer <code>Europe/Athens</code> to the Greek + <code>Europe/Αθήνα</code> or the Romanized + <code>Europe/Athína</code>. The POSIX file name restrictions encourage this guideline. </li> <li> Use the most populous among locations in a region, - e.g., prefer '<code>Shanghai</code>' to - '<code>Beijing</code>'. + e.g., prefer <code>Asia/Shanghai</code> to + <code>Asia/Beijing</code>. Among locations with similar populations, pick the best-known - location, e.g., prefer '<code>Rome</code>' to - '<code>Milan</code>'. + location, e.g., prefer <code>Europe/Rome</code> to + <code>Europe/Milan</code>. </li> <li> - Use the singular form, e.g., prefer '<code>Canary</code>' to - '<code>Canaries</code>'. + Use the singular form, e.g., prefer <code>Atlantic/Canary</code> to + <code>Atlantic/Canaries</code>. </li> <li> Omit common suffixes like '<code>_Islands</code>' and '<code>_City</code>', unless that would lead to ambiguity. - E.g., prefer '<code>Cayman</code>' to - '<code>Cayman_Islands</code>' and '<code>Guatemala</code>' to - '<code>Guatemala_City</code>', but prefer - '<code>Mexico_City</code>' to '<code>Mexico</code>' + E.g., prefer <code>America/Cayman</code> to + <code>America/Cayman_Islands</code> and + <code>America/Guatemala</code> to + <code>America/Guatemala_City</code>, but prefer + <code>America/Mexico_City</code> to + <code>America/Mexico</code> because <a href="https://en.wikipedia.org/wiki/Time_in_Mexico">the country of Mexico has several time zones</a>. </li> @@ -245,13 +255,14 @@ in decreasing order of importance: </li> <li> Omit '<code>.</code>' from abbreviations in names. - E.g., prefer '<code>St_Helena</code>' to '<code>St._Helena</code>'. + E.g., prefer <code>Atlantic/St_Helena</code> to + <code>Atlantiic/St._Helena</code>. </li> <li> Do not change established names if they only marginally violate the above guidelines. - For example, don't change the existing name '<code>Rome</code>' to - '<code>Milan</code>' merely because Milan's population has grown + For example, do not change the existing name <code>Europe/Rome</code> to + <code>Europe/Milan</code> merely because Milan's population has grown to be somewhat greater than Rome's. </li> <li> @@ -318,8 +329,10 @@ in decreasing order of importance: Use three to six characters that are ASCII alphanumerics or '<code>+</code>' or '<code>-</code>'. Previous editions of this database also used characters like - '<code> </code>' and '<code>?</code>', but these characters have a - special meaning to the shell and cause commands like + space and '<code>?</code>', but these characters have a + special meaning to the + <a href="https://en.wikipedia.org/wiki/Unix_shell">UNIX shell</a> + and cause commands like '<code><a href="http://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set">set</a> `<a href="http://pubs.opengroup.org/onlinepubs/9699919799/utilities/date.html">date</a>`</code>' to have unexpected effects. @@ -688,7 +701,7 @@ href="https://www.dissentmagazine.org/blog/booked-a-global-history-of-time-vanes subsecond accuracy is needed. </li> <li> - Civil time was not based on atomic time before 1972, and we don't + Civil time was not based on atomic time before 1972, and we do not know the history of <a href="https://en.wikipedia.org/wiki/Earth's_rotation">earth's rotation</a> accurately enough to map <a @@ -720,7 +733,7 @@ href="https://www.dissentmagazine.org/blog/booked-a-global-history-of-time-vanes Ideally it would contain information about when data entries are incomplete or dicey. Partial temporal knowledge is a field of active research, though, - and it's not clear how to apply it here. + and it is not clear how to apply it here. </li> </ul> @@ -764,7 +777,7 @@ an older <code>zic</code>. Unfortunately, the POSIX <code>TZ</code> string takes a form that is hard to describe and is error-prone in practice. - Also, POSIX <code>TZ</code> strings can't deal with daylight + Also, POSIX <code>TZ</code> strings cannot deal with daylight saving time rules not based on the Gregorian calendar (as in Iran), or with situations where more than two time zone abbreviations or <abbr>UT</abbr> offsets are used in an area. @@ -874,7 +887,7 @@ an older <code>zic</code>. need access to multiple time zone rulesets. </li> <li> - In POSIX, there's no tamper-proof way for a process to learn the + In POSIX, there is no tamper-proof way for a process to learn the system's best idea of local wall clock. (This is important for applications that an administrator wants used only at certain times – without regard to whether the @@ -973,14 +986,16 @@ an older <code>zic</code>. by subsequent calls to <code>localtime</code>. Source code for portable applications that "must" run on local wall clock time should call <code>tzsetwall</code>; - if such code is moved to "old" systems that don't - provide <code>tzsetwall</code>, you won't be able to generate an + if such code is moved to "old" systems that do not + provide <code>tzsetwall</code>, you will not be able to generate an executable program. (These functions also arrange for local wall clock time to be used if <code>tzset</code> is called – directly or - indirectly – and there's no <code>TZ</code> environment + indirectly – and there is no <code>TZ</code> environment variable; portable applications should not, however, rely on this - behavior since it's not the way SVR2 systems behave.) + behavior since it is not the way <a + href="https://en.wikipedia.org/wiki/UNIX_System_V#SVR2"><abbr>SVR2</abbr></a> + systems behave.) </li> <li> Negative <code>time_t</code> values are supported, on systems @@ -1040,7 +1055,7 @@ The vestigial <abbr>API</abbr>s are: <li> The <a href="https://en.wikipedia.org/wiki/Version_7_Unix">7th Edition UNIX</a> <code>timezone</code> function is not present in this - package; it's impossible to reliably map <code>timezone</code>'s + package; it is impossible to reliably map <code>timezone</code>'s arguments (a "minutes west of <abbr>GMT</abbr>" value and a "daylight saving time in effect" flag) to a time zone abbreviation, and we refuse to guess. @@ -1052,7 +1067,9 @@ The vestigial <abbr>API</abbr>s are: zone abbreviation to use. </li> <li> - The <abbr>4.2BSD</abbr> <code>gettimeofday</code> function is not + The <a + href="https://en.wikipedia.org/wiki/History_of_the_Berkeley_Software_Distribution…"><abbr>4.2BSD</abbr></a> + <code>gettimeofday</code> function is not used in this package. This formerly let users obtain the current <abbr>UTC</abbr> offset and <abbr>DST</abbr> flag, but this functionality was removed in @@ -1061,7 +1078,7 @@ The vestigial <abbr>API</abbr>s are: <li> In <abbr>SVR2</abbr>, time conversion fails for near-minimum or near-maximum <code>time_t</code> values when doing conversions - for places that don't use <abbr>UT</abbr>. + for places that do not use <abbr>UT</abbr>. This package takes care to do these conversions correctly. A comment in the source code tells how to get compatibly wrong results. @@ -1170,11 +1187,11 @@ They sometimes disagree. <p> Some people's work schedules use <a href="https://en.wikipedia.org/wiki/Timekeeping on Mars">Mars time</a>. -Jet Propulsion Laboratory (JPL) coordinators have kept Mars time on -and off at least since 1997 for the +Jet Propulsion Laboratory (JPL) coordinators kept Mars time on +and off during the <a href="https://en.wikipedia.org/wiki/Mars_Pathfinder#End_of_mission">Mars Pathfinder</a> mission. -Some of their family members have also adapted to Mars time. +Some of their family members also adapted to Mars time. Dozens of special Mars watches were built for JPL workers who kept Mars time during the Mars Exploration Rovers mission (2004). These timepieces look like normal Seikos and Citizens but use Mars @@ -1262,7 +1279,7 @@ Sources for time on other planets: Jia-Rui Chong, "<a href="http://articles.latimes.com/2004/jan/14/science/sci-marstime14">Workdays Fit for a Martian</a>", <cite>Los Angeles Times</cite> - (2004-01-14), pp A1, A20-A21. + (2004-01-14), pp A1, A20–A21. </li> <li> Tom Chmielewski, -- 2.14.3

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Namibia Time Zone
by Mark Plaatje April 4, 2018

April 4, 2018

Good Day Kindly update your database to reflect that no Daylight Savings Time will be effected in 2018. https://www.timeanddate.com/time/change/namibia/windhoek?year=2018 https://www.namibian.com.na/65921/read/No-time-change-on-Sunday http://www.xinhuanet.com/english/2018-04/03/c_137086167.htm https://www.namibian.com.na/65942/read/Confusion-over-time-change Regards, Mark Plaatje Manager : Fraud Mobile Telecommunications Ltd Tel: +264818882842 Fax: E-mail: MPlaatje(a)mtc.com.na <mailto:MPlaatje@mtc.com.na>http://www.mtc.com.na [X]<http://www.mtc.com.na/> ________________________________ This e-mail message and any attachment are subject to the following terms and conditions http://www.mtc.com.na/legal/disclaimer

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