- tz - lists.iana.org

Lack of "initial" transitions for some zones
by Jon Skeet July 22, 2015

July 22, 2015

I suspect this is just a matter of how the data has been specified, but it's a little odd... I'm looking at the output of zic for each zone, and almost all zones start with a "transition" for some timestamp in the long distant past - including fixed zones such as UTC and Etc/*. However, the legacy "root" zones of CET, EET, PST8PDT etc don't have this initial "transition" in the file - unless I'm misinterpreting it, which is always a possibility. Would it make sense to adjust either the data or zic to make all zic output (in the 8-byte-timestamp format, at least) cover all of time? I realize that this "extra" data (presumably an insertion of "standard time until the first transition") may well not be historically accurate - but I doubt that it would be any less accurate than other zones in a similar situation. Jon

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No DST for Uruguay since 2015
by Guillermo Pereyra July 20, 2015

July 20, 2015

http://archivo.presidencia.gub.uy/sci/decretos/2015/06/cons_min_201.pdf

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About the core city of a tz region
by David Patte ₯ July 20, 2015

July 20, 2015

I am curious about the protocol that tz uses to specify the name of each tz region. Is the core city in a region always the most populous city in the tz region? And what is done if a smaller city's population overtakes the named city? Is the zone renamed? Also, since historical data (pre-1970) is now maintained only for the named city in a region, does it not make sense to use the population as of 1970, since the historical records actually affected more people at that time?

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Zone America/Glace_Bay
by Hank W. July 20, 2015

July 20, 2015

I just read in Wikipedia that Glace Bay, Nova Scotia, Canada existed only from 1901 to 1995. The government of Glace Bay was dissolved on 1 Aug 1995 when eight municipalities, including Glace Bay, were consolidated to form Cape Breton (a.k.a. CBRM, short for Cape Breton Regional Municipality), which is currently the second-most populous municipality in Nova Scotia after Halifax. Wikipedia shows Cape Bretons coordinates as 46° 9 north latitude by 60° 10 west longitude. That longitude corresponds to a local mean time of UTC-4:00:40. https://en.wikipedia.org/wiki/Glace_Bay https://en.wikipedia.org/wiki/Cape_Breton_Regional_Municipality Hank Wisniewski of Austin, Texas, U.S.A.

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Type values in rules
by Jon Skeet July 20, 2015

July 20, 2015

Hi folks, It wasn't until last night that I first saw a non "-" entry for a type line - Australia/Adelaide had rules of Rule AS 1990 1994 even Mar Sun>=18 2:00s 0 - Rule AS 1990 1994 odd Mar Sun>=1 2:00s 0 - until release 2000f. Now in Noda Time I could probably support non-infinite rules with a fixed set of types (hopefully just odd and even), but it would be a bit of work. If type values are effectively obsolete, I may not bother. So, is it just coincidence that there have been no uses of the Type field in the released data since 2000f, or is this effectively policy now? (I can understand keeping the functionality for private usage, where others may use zic with their own data sets, but for Noda Time I'm not worried about that. Jon

2 2

Full timezone names
by William Roberts July 20, 2015

July 20, 2015

Hi I'm currently using the tz data that comes with PHP. Is there a way of retrieving the full timezone name from the tz database, eg. Central European Time, Eastern Standard Time etc. So far I haven't been able to, so am using the CLDR repository which assigns a metazone to each timezone from the tz database, and from that I can get the full timezone name but it's not ideal as they don't always match exactly with the abbreviations from the tz data. Are there any plans to enable the full timezone names to be retrieved from the tz database the same way you would the abbreviations in PHP for example, or is getting them from the CLDR repository the best way to go about it? Thanks.

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Re: [tz] Full timezone names
by Matt Johnson July 20, 2015

July 20, 2015

CLDR is indeed the best resource available for full names, particularly due to localization concerns. AFAIK, there is no desire to replicate this in tzdb. Abbreviations are particularly tricky. Not only might they change per language, but there might not be any "real" abbreviation in use by people in the region. ________________________________ From: William Roberts<mailto:wmr501@outlook.com> Sent: ‎7/‎19/‎2015 8:57 PM To: tz(a)iana.org<mailto:tz@iana.org> Subject: [tz] Full timezone names Hi I'm currently using the tz data that comes with PHP. Is there a way of retrieving the full timezone name from the tz database, eg. Central European Time, Eastern Standard Time etc. So far I haven't been able to, so am using the CLDR repository which assigns a metazone to each timezone from the tz database, and from that I can get the full timezone name but it's not ideal as they don't always match exactly with the abbreviations from the tz data. Are there any plans to enable the full timezone names to be retrieved from the tz database the same way you would the abbreviations in PHP for example, or is getting them from the CLDR repository the best way to go about it? Thanks.

1 0

Behaviour in the face of multiple identical rules
by Jon Skeet July 19, 2015

July 19, 2015

This is more of an awareness-raising post than anything else... the data here is very far in the past. While trying to validate Noda Time against zic, I came up against issues with data releases between 1993 and 1996 in Egypt/Cairo. It turns out that this is because the Egypt rule is duplicated in the asia file, and this affects things. As a smallish example, if you create a file called testzone like this: Rule Egypt 1900 only - Oct 1 0:00 0 - > Rule Egypt 1943 1945 - Nov 1 0:00 0 - > Rule Egypt 1945 only - Apr 16 0:00 1:00 " > DST" > Rule Egypt 1957 only - May 10 0:00 1:00 " > DST" > Rule Egypt 1957 1958 - Oct 1 0:00 0 - > Rule Egypt 1958 only - May 1 0:00 1:00 " > DST" > # Rule Egypt 1957 only - May 10 0:00 1:00 " > DST" > > # Zone NAME GMTOFF RULES FORMAT [UNTIL] > Zone Africa/Cairo 2:05:00 - LMT 1900 Oct > 2:00 Egypt EET%s ... then execute: $ zic -d . testzone && zdump -v -c 1955,1958 $PWD/Africa/Cairo You'll see output like this for the May 1957 transition: .../Africa/Cairo Thu May 9 21:59:59 1957 UT = Thu May 9 23:59:59 1957 > EET isdst=0 gmtoff=7200 > ...Africa/Cairo Thu May 9 22:00:00 1957 UT = Fri May 10 01:00:00 1957 > EET DST isdst=1 gmtoff=10800 That looks okay - the transition is around midnight, as described. If, however, you uncomment that last "Rule" line above - which is an exact duplicate of the earlier one - you get: .../Africa/Cairo Thu May 9 20:59:59 1957 UT = Thu May 9 22:59:59 1957 > EET isdst=0 gmtoff=7200 > .../Africa/Cairo Thu May 9 21:00:00 1957 UT = Fri May 10 00:00:00 1957 > EET DST isdst=1 gmtoff=10800 Now the transition is one hour earlier. As it happens, this duplicate rule doesn't make any difference to Noda Time - it still emits the first output. I *strongly suspect* that I shouldn't care about this - that situations with duplicate rules should be deemed out of scope for any implementation. However, if anyone can think of any good justification why an implementation *should* behave like zic in this case, I'd be really interested to hear it. (I'm not asking for zic to change here. It already emits a warning because the rule is defined in multiple files, and I think that's good enough.) Jon

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No leap second on 2015-12-31.
by Tim Parenti July 18, 2015

July 18, 2015

Per IERS Bulletin C50 (2015-07-07), no leap second will be observed on 2015-12-31. This patch updates leap-seconds.list from NIST. -- Tim Parenti

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[Announce] C++11 / C++14 IANA Time Zone Database Parser
by Howard Hinnant July 18, 2015

July 18, 2015

http://howardhinnant.github.io/tz.html It is still very early in its development process. It has only been tested on OS X 10.10.4. It requires at least C++11, and prefers C++14. Contributions to making it more portable to reasonable C++11 and beyond platforms are welcomed. Howard

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[PROPOSED PATCH] Fix zdump problem with abbrevs like '-05'
by Paul Eggert July 17, 2015

July 17, 2015

* zdump.c (is_digit): New macro, copied from private.h. (abbrok): Use it. Allow abbreviations that (when quoted) conform to POSIX.1-2001 or later. * NEWS: Document this. --- NEWS | 3 ++- zdump.c | 28 +++++++++++----------------- 2 files changed, 13 insertions(+), 18 deletions(-) diff --git a/NEWS b/NEWS index 498e77b..101a1e5 100644 --- a/NEWS +++ b/NEWS @@ -21,7 +21,8 @@ Unreleased, experimental changes Changes affecting code - zic no longer warns about valid time zone abbreviations like '-05'. + zdump and zic no longer warn about valid time zone abbreviations + like '-05'. Release 2015e - 2015-06-13 10:56:02 -0700 diff --git a/zdump.c b/zdump.c index adb806c..64ff6ce 100644 --- a/zdump.c +++ b/zdump.c @@ -269,6 +269,9 @@ static void show(timezone_t, char *, time_t, bool); static const char *tformat(void); static time_t yeartot(intmax_t) ATTRIBUTE_PURE; +/* Unlike <ctype.h>'s isdigit, this also works if c < 0 | c > UCHAR_MAX. */ +#define is_digit(c) ((unsigned)(c) - '0' <= 9) + /* Is A an alphabetic character in the C locale? */ static bool is_alpha(char a) @@ -485,25 +488,16 @@ abbrok(const char *const abbrp, const char *const zone) if (warned) return; cp = abbrp; - wp = NULL; - while (is_alpha(*cp)) + while (is_alpha(*cp) || is_digit(*cp) || *cp == '-' || *cp == '+') ++cp; - if (cp - abbrp == 0) - wp = _("lacks alphabetic at start"); - else if (cp - abbrp < 3) - wp = _("has fewer than 3 alphabetics"); + if (cp - abbrp < 3) + wp = _("has fewer than 3 characters"); else if (cp - abbrp > 6) - wp = _("has more than 6 alphabetics"); - if (wp == NULL && (*cp == '+' || *cp == '-')) { - ++cp; - if ('0' <= *cp && *cp <= '9') - if (*cp++ == '1' && '0' <= *cp && *cp <= '4') - cp++; - if (*cp != '\0') - wp = _("differs from POSIX standard"); - } - if (wp == NULL) - return; + wp = _("has more than 6 characters"); + else if (*cp) + wp = _("has characters other than ASCII alphanumerics, '-' or '+'"); + else + return; fflush(stdout); fprintf(stderr, _("%s: warning: zone \"%s\" abbreviation \"%s\" %s\n"), -- 2.1.0

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[PROPOSED PATCH] Don't warn about abbreviations like '-05'
by Paul Eggert July 15, 2015

July 15, 2015

* NEWS, zic.8: Document this. * zic.c (newabbr): Allow abbreviations that (when quoted) conform to POSIX.1-2001 or later. --- NEWS | 4 ++++ zic.8 | 2 ++ zic.c | 20 ++++---------------- 3 files changed, 10 insertions(+), 16 deletions(-) diff --git a/NEWS b/NEWS index 041983c..498e77b 100644 --- a/NEWS +++ b/NEWS @@ -19,6 +19,10 @@ Unreleased, experimental changes installed data files for Europe/Simferopol and Europe/Tallinn. It does not affect timestamps. (Thanks to Howard Hinnant.) + Changes affecting code + + zic no longer warns about valid time zone abbreviations like '-05'. + Release 2015e - 2015-06-13 10:56:02 -0700 diff --git a/zic.8 b/zic.8 index cf78ae3..968cc6f 100644 --- a/zic.8 +++ b/zic.8 @@ -376,6 +376,8 @@ of the time zone abbreviation goes. Alternately, a slash (/) separates standard and daylight abbreviations. +To conform to POSIX, a time zone abbreviation should contain only +alphanumeric ASCII characters, "+" and "\*-". .TP .B UNTILYEAR [MONTH [DAY [TIME]]] The time at which the UT offset or the rule(s) change for a location. diff --git a/zic.c b/zic.c index f51fc48..6fac4e3 100644 --- a/zic.c +++ b/zic.c @@ -2893,27 +2893,15 @@ newabbr(const char *const string) register const char * cp; const char * mp; - /* - ** Want one to ZIC_MAX_ABBR_LEN_WO_WARN alphabetics - ** optionally followed by a + or - and a number from 1 to 14. - */ cp = string; mp = NULL; - while (is_alpha(*cp)) + while (is_alpha(*cp) || ('0' <= *cp && *cp <= '9') + || *cp == '-' || *cp == '+') ++cp; - if (cp - string == 0) -mp = _("time zone abbreviation lacks alphabetic at start"); if (noise && cp - string < 3) -mp = _("time zone abbreviation has fewer than 3 alphabetics"); + mp = _("time zone abbreviation has fewer than 3 characters"); if (cp - string > ZIC_MAX_ABBR_LEN_WO_WARN) -mp = _("time zone abbreviation has too many alphabetics"); - if (mp == NULL && (*cp == '+' || *cp == '-')) { - ++cp; - if (is_digit(*cp)) - if (*cp++ == '1' && - *cp >= '0' && *cp <= '4') - ++cp; - } + mp = _("time zone abbreviation has too many characters"); if (*cp != '\0') mp = _("time zone abbreviation differs from POSIX standard"); if (mp != NULL) -- 2.1.0

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Re: [tz] Uruguay out of DST
by Pablo Camargo July 13, 2015

July 13, 2015

Hello! Just to confirm: "Uruguay out of DST" is official. Next source in Spanish (presidential decree). >>> http://archivo.presidencia.gub.uy/sci/decretos/2015/06/cons_min_201.pdf Context: >>> http://presidencia.gub.uy/normativa/decretos/decretos-06-2015 Media coverage of the news (text) had better coverage, but the official communication was there (pdf). So we are looking forward for a future update of tz. Thanks! P.Camargo.

3 2

Unnecessary faux transition in Atlantic/Canary 1980 Sep/28
by Howard Hinnant July 13, 2015

July 13, 2015

Hi, I wouldn’t call this a bug, but a potential database inefficiency. I’m working on a TZ parser and using it to explore the timezone transitions as specified by the timezone database. I’m looking at the Atlantic/Canary transition on 1980 Sep 28 0:00s. At this time the timezone transitions from a permanent saving of 1:00 and abbreviation of WEST to a rule based savings specified by EU: 1980-09-27 23:59:59u = 1980-09-28 00:59:59 WEST // as specified by 0:00 1:00 WEST 1980-09-28 00:00:00u = 1980-09-28 01:00:00 WEST // as specified by 0:00 EU WE%sT I.e. there is no change in offset, savings, or abbreviation. And then an hour later EU specifies a savings and abbreviation change: 1980-09-28 00:59:59u = 1980-09-28 01:59:59 WEST 1980-09-28 01:00:00u = 1980-09-28 01:00:00 WET My observation is that this is a lot of transitions for one night. Would it not be better to delay the transition from "0:00 1:00 WEST” to "0:00 EU WE%sT” by one hour, and thus have only one transition instead of two? Here is a change that does so: diff --git a/europe b/europe index c64c41b..630c234 100644 --- a/europe +++ b/europe @@ -2922,7 +2922,7 @@ Zone Africa/Ceuta -0:21:16 - LMT 1901 Zone Atlantic/Canary -1:01:36 - LMT 1922 Mar # Las Palmas de Gran C. -1:00 - CANT 1946 Sep 30 1:00 # Canaries T 0:00 - WET 1980 Apr 6 0:00s - 0:00 1:00 WEST 1980 Sep 28 0:00s + 0:00 1:00 WEST 1980 Sep 28 1:00s 0:00 EU WE%sT # IATA SSIM (1996-09) says the Canaries switch at 2:00u, not 1:00u. # Ignore this for now, as the Canaries are part of the EU. Howard

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Europe/Chisinau Timezone
by Roman Tudos July 11, 2015

July 11, 2015

Please be informed that according Moldavian Law dst start on last last Sunday of March end on last sunday of October at 02:00 to 03:00 and at 03:00 to 02:00 respectively 2015Sun, 29 Mar, 02:00EET <http://www.timeanddate.com/time/zones/eet> → EEST <http://www.timeanddate.com/time/zones/eest>+1 hour (DST start)UTC+3h Sun, 25 Oct, 03:00EEST <http://www.timeanddate.com/time/zones/eest> → EET <http://www.timeanddate.com/time/zones/eet>-1 hour (DST end)UTC+2h2016Sun, 27 Mar, 02:00EET <http://www.timeanddate.com/time/zones/eet> → EEST <http://www.timeanddate.com/time/zones/eest>+1 hour (DST start)UTC+3h Sun, 30 Oct, 03:00EEST <http://www.timeanddate.com/time/zones/eest> → EET <http://www.timeanddate.com/time/zones/eet>-1 hour (DST end)UTC+2h2017Sun, 26 Mar, 02:00EET <http://www.timeanddate.com/time/zones/eet> → EEST <http://www.timeanddate.com/time/zones/eest>+1 hour (DST start)UTC+3h Sun, 29 Oct, 03:00EEST <http://www.timeanddate.com/time/zones/eest> → EET <http://www.timeanddate.com/time/zones/eet>-1 hour (DST end)UTC+2h2018Sun, 25 Mar, 02:00EET <http://www.timeanddate.com/time/zones/eet> → EEST <http://www.timeanddate.com/time/zones/eest>+1 hour (DST start)UTC+3h Sun, 28 Oct, 03:00EEST <http://www.timeanddate.com/time/zones/eest> → EET <http://www.timeanddate.com/time/zones/eet>-1 hour (DST end)UTC+2h Please take consideration for changes in tzdata PS. Sorry for my english -- Vita sine libertate, nihil

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Discrepancies in time zone data interpretation at standard offset changes
by Jon Skeet July 11, 2015

July 11, 2015

Heads up for Stephen Colebourne: this post highlights a discrepancy between Joda Time and tzdump, so you may want to read carefully :) This is in relation to my earlier message about the text format. My confusion here is the reason I'm anxious to see canonical data :) Currently, both Joda Time and Noda Time have some interesting code when working out the transitions for a time zone which checks whether the later transition occurs at the same *local* time as the earlier transition, and if so extends the earlier transition to consume the later one. I've worked out that this is basically to handle an oddity that sometimes occurs when standard offsets change. One example of a zone in which this happens is America/Juneau. Here are the zone lines from 2015e, and I've highlighted the ones we're immediately concerned with: Zone America/Juneau 15:02:19 - LMT 1867 Oct 18 -8:57:41 - LMT 1900 Aug 20 12:00 -8:00 - PST 1942 -8:00 US P%sT 1946 -8:00 - PST 1969 -8:00 US P%sT 1980 Apr 27 2:00 -9:00 US Y%sT 1980 Oct 26 2:00 * -8:00 US P%sT 1983 Oct 30 2:00* * -9:00 US Y%sT 1983 Nov 30* -9:00 US AK%sT The US rules in force at the time are: Rule US 1967 2006 - Oct lastSun 2:00 0 S Rule US 1976 1986 - Apr lastSun 2:00 1:00 D So, the first bolded zone line comes to an end at the instant of the transition into standard time, while standard time is -8 (so a wall offset of -7). I assume this transition should *not* be included in the eventual set of transitions (i.e. the bound given is exclusive). This would occur at 1983-10-30T09:00Z. Now, in the second bolded zone line, the standard offset is -9 instead, so the transition into daylight saving time would occur at 1983-10-30T10:00Z. So looking at the rules in a naive way, residents of Juneau would have to change their watches twice on October 30th 1983. At 2am they'd put their watches back an hour to account for the change in standard time (but still be in daylight saving time)... and then when it next hit 2am they'd put their watches back *another* hour to account for the transition into standard time. Now, I'm pretty sure that's not what's intended, and indeed zdump shows just a single transition setting local time back two hours at 1983-10-30T09:00Z: America/Juneau Sun Oct 30 08:59:59 1983 UTC = Sun Oct 30 01:59:59 1983 PDT isdst=1 America/Juneau Sun Oct 30 09:00:00 1983 UTC = Sun Oct 30 00:00:00 1983 YST isdst=0 ... whereas Noda Time (and, I've just checked, Joda Time) have a single transition at 1983-10-30T10:00Z instead. Is it documented somewhere what should happen in this case? (As a side question, is there a single canonical place documenting the time zone data format? I've found various sources over the years, but it would be nice to have somewhere canonical - ideally either within each release or on the IANA home page. The Theory file gives a lot of interesting more abstract information, but a single place saying "Here is what each file in the release means, with details of its format" would be very welcome. Apologies if it already exists and I've just missed it...) Jon

2 1

UY Timezone DST changed since June 2015
by Nicolas Antoniello July 9, 2015

July 9, 2015

Hi folks, Just to request a Timezone DB update as Past June 2015, Uruguay (UY) eliminated the DST Timezone change (now it's UTC-3 all year). So for Montevideo (capital city) and all rest of Uruguayan cities now is all year UTC-3. Thanks in advance, Nicolas

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Greetings from Mongolia
by amgalan tsogtgerel July 4, 2015

July 4, 2015

Dear Paul Eggert, Greetings from Mongolia. I am writing this letter on behalf of the Communications Regulatory Commission of Mongolia. The Mongolian Government has approved the Resolution ? 82, dated 09 March 2015, to use Daylight Saving Time (DST) every year from last week of March until last week of September from 2015. According to the Resolution, the clocks in Mongolia has set forward one hour at 2 : 00 (2 am) local time. Unfortunately, some of system, service and software which are widely using in Mongolia have not updated their time zone. Regarding this issue, the CRC has sent you official letter dated 15th June 2015 to you for your support on above mentioned issue and we have not received any response from you yet. Here I attached the copy of letter. Thank you for your understanding. I look forward hearing from you soon. BR, Amgalan Ts. (Ms) Foreign Relation Officer, Legal, Information and Administration Dept, CRC of Mongolia. mobile: 976 91112268 phone: 976 11 304258,304257 fax:976 11 327720 e-mail: amgalants(a)crc.gov.mn<mailto:amgalants@crc.gov.mn>

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[PROPOSED_PATCH] Moldova DST transitions were off by an hour
by Paul Eggert July 2, 2015

July 2, 2015

* NEWS: Moldova starts and ends DST at 00:00 UTC, not at 01:00 UTC. (Thanks to Roman Tudos.) * europe (Moldova): New rule. (Europe/Chisinau): Use it. --- NEWS | 5 +++++ europe | 14 +++++++++++++- 2 files changed, 18 insertions(+), 1 deletion(-) diff --git a/NEWS b/NEWS index 156da23..f0fedbd 100644 --- a/NEWS +++ b/NEWS @@ -6,6 +6,11 @@ Unreleased, experimental changes Uruguay will stop observing DST. (Thanks to Steffen Thorsen.) + Changes affecting past and future time stamps + + Moldova starts and ends DST at 00:00 UTC, not at 01:00 UTC. + (Thanks to Roman Tudos.) + Changes affecting installed data files Data entries have been simplified for Atlantic/Canary, Europe/Simferopol, diff --git a/europe b/europe index a5e95bb..7cbf1f8 100644 --- a/europe +++ b/europe @@ -1763,6 +1763,18 @@ Zone Europe/Malta 0:58:04 - LMT 1893 Nov 2 0:00s # Valletta # News from Moldova (in russian): # http://ru.publika.md/link_317061.html +# From Roman Tudos (2015-07-02): +# http://lex.justice.md/index.php?action=view&view=doc&lang=1&id=355077 +# From Paul Eggert (2015-07-01): +# The abovementioned official link to IGO1445-868/2014 states that +# 2014-10-26's fallback transition occurred at 03:00 local time. Also, +# http://www.trm.md/en/social/la-30-martie-vom-trece-la-ora-de-vara +# says the 2014-03-30 spring-forward transition was at 02:00 local time. +# Guess that since 1997 Moldova has switched one hour before the EU. + +# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S +Rule Moldova 1997 max - Mar lastSun 2:00 1:00 S +Rule Moldova 1997 max - Oct lastSun 3:00 0 - # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Europe/Chisinau 1:55:20 - LMT 1880 @@ -1777,7 +1789,7 @@ Zone Europe/Chisinau 1:55:20 - LMT 1880 2:00 Russia EE%sT 1992 2:00 E-Eur EE%sT 1997 # See Romania commentary for the guessed 1997 transition to EU rules. - 2:00 EU EE%sT + 2:00 Moldova EE%sT # Monaco # Shanks & Pottenger give 0:09:20 for Paris Mean Time; go with Howse's -- 2.1.0

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Trivia: Sunrise in Santiago
by Hank W. June 30, 2015

June 30, 2015

Today, 30 June 2015, is the latest sunrise of winter in Santiago, Chile. I was curious about what that latest time is, not only because this is Chile's first winter on "permanent" Summer Time, but also because UTC-3 is so far from Santiago's LMT of UTC-4.713. Sunrise in Santiago today will be at 08:48 CLST! Hank Wisniewski of Austin, Texas, U.S.A. "'Tis better to be silent and thought the fool than to speak and dispel all doubt." -unknown

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Best practices for upcoming leap second event
by Paul Eggert June 28, 2015

June 28, 2015

If you're responsible for proper timekeeping you probably have already thought about the upcoming leap second at the end of Tuesday 2015-06-30 UTC. This is the first leap second in eighteen years that has fallen on a non-holiday weekday. It might not hurt to run through your checklist again, and (if you haven't already done so) compare it to the checklist recommended by GPS.GOV, NAVCEN, NCCIC, NIST, and USNO. You can find that checklist here: http://www.gps.gov/news/2015/05/leap-second/2015-best-practices-for-leap-se… The new leap second has been in the tz database since release 2015a dated 2015-01-29 22:35:20 -0800, so if you're newer than that you should be good as far as tz is concerned. In the typical case where you're not using tz's leap-second support, you don't need to worry about tz at all.

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Three more tweaks
by Howard Hinnant June 21, 2015

June 21, 2015

Hi, I’ve surveyed the entire database for transitions 24h or less apart with one of them being a faux transition. I found only 6. You just eliminated the first. Two more are in Europe/Istanbul and I see no way to eliminate the faux transition. Here are the remaining 3 with explanations and fixes: ——————————— Europe/Simferopol 1996 Mar 31: 1996-03-30 20:59:59u = 1996-03-30 23:59:59 MSK // 03:00:00 E-Eur MSK/MSD 1996-03-30 21:00:00u = 1996-03-31 01:00:00 MSD // 03:00:00 E-Eur MSK/MSD And then 3h later: 1996-03-30 23:59:59u = 1996-03-31 03:59:59 MSD // 03:00:00 E-Eur MSK/MSD 1996-03-31 00:00:00u = 1996-03-31 04:00:00 MSD // 03:00:00 01:00 MSD The second faux transition can be combined with the first actual transition with: diff --git a/europe b/europe index 630c234..1242927 100644 --- a/europe +++ b/europe @@ -2364,7 +2364,7 @@ Zone Europe/Simferopol 2:16:24 - LMT 1880 # changed in May. 2:00 E-Eur EE%sT 1994 May # From IATA SSIM (1994/1997), which also says that Kerch is still like Kiev. - 3:00 E-Eur MSK/MSD 1996 Mar 31 3:00s + 3:00 E-Eur MSK/MSD 1996 Mar 31 0:00s 3:00 1:00 MSD 1996 Oct 27 3:00s # IATA SSIM (1997-09) says Crimea switched to EET/EEST. # Assume it happened in March by not changing the clocks. ——————————— Europe/Sofia 1982 Sep 26: 1982-09-25 22:59:59u = 1982-09-26 01:59:59 EEST // 02:00:00 Bulg EE%sT 1982-09-25 23:00:00u = 1982-09-26 02:00:00 EEST // 02:00:00 C-Eur EE%sT And then 1h later: 1982-09-25 23:59:59u = 1982-09-26 02:59:59 EEST // 02:00:00 C-Eur EE%sT 1982-09-26 00:00:00u = 1982-09-26 02:00:00 EET // 02:00:00 C-Eur EE%sT The first faux transition can be merged with the second actual transition with: diff --git a/europe b/europe index 630c234..f096de5 100644 --- a/europe +++ b/europe @@ -845,7 +845,7 @@ Zone Europe/Sofia 1:33:16 - LMT 1880 1:00 C-Eur CE%sT 1945 1:00 - CET 1945 Apr 2 3:00 2:00 - EET 1979 Mar 31 23:00 - 2:00 Bulg EE%sT 1982 Sep 26 2:00 + 2:00 Bulg EE%sT 1982 Sep 26 3:00 2:00 C-Eur EE%sT 1991 2:00 E-Eur EE%sT 1997 2:00 EU EE%sT ——————————— Europe/Tallinn 1999 Nov 1: 1999-10-31 00:59:59u = 1999-10-31 03:59:59 EEST // 02:00:00 EU EE%sT 1999-10-31 01:00:00u = 1999-10-31 03:00:00 EET // 02:00:00 EU EE%sT And then 21h later: 1999-10-31 21:59:59u = 1999-10-31 23:59:59 EET // 02:00:00 EU EE%sT 1999-10-31 22:00:00u = 1999-11-01 00:00:00 EET // 02:00:00 EET The second faux transition can be combined with the first actual transition with: diff --git a/europe b/europe index 630c234..c788416 100644 --- a/europe +++ b/europe @@ -1084,7 +1084,7 @@ Zone Europe/Tallinn 1:39:00 - LMT 1880 3:00 Russia MSK/MSD 1989 Mar 26 2:00s 2:00 1:00 EEST 1989 Sep 24 2:00s 2:00 C-Eur EE%sT 1998 Sep 22 - 2:00 EU EE%sT 1999 Nov 1 + 2:00 EU EE%sT 1999 Oct 31 4:00 2:00 - EET 2002 Feb 21 2:00 EU EE%sT Thanks, Howard

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[tz-announce] 2015e release of tz code and data available
by Paul Eggert June 13, 2015

June 13, 2015

The 2015e release of the tz code and data is available. It reflects the following changes, which were either circulated on the tz mailing list or are relatively minor technical or administrative changes: Changes affecting future time stamps Morocco will suspend DST from 2015-06-14 03:00 through 2015-07-19 02:00, not 06-13 and 07-18 as we had guessed. (Thanks to Milamber.) Assume Cayman Islands will observe DST starting next year, using US rules. Although it isn't guaranteed, it is the most likely. Changes affecting data format The file 'iso3166.tab' now uses UTF-8, so that its entries can better spell the names of Åland Islands, Côte d'Ivoire, and Réunion. Changes affecting code When displaying data, tzselect converts it to the current locale's encoding if the iconv command works. (Problem reported by random832.) tzselect no longer mishandles Dominica, fixing a bug introduced in Release 2014f. (Problem reported by Owen Leibman.) zic -l no longer fails when compiled with -DTZDEFAULT=\"/etc/localtime\". This fixes a bug introduced in Release 2014f. (Problem reported by Leonardo Chiquitto.) Here are links to the release files: ftp://ftp.iana.org/tz/releases/tzcode2015e.tar.gz ftp://ftp.iana.org/tz/releases/tzdata2015e.tar.gz The files are also available via HTTP as follows: http://www.iana.org/time-zones/repository/releases/tzcode2015e.tar.gz http://www.iana.org/time-zones/repository/releases/tzdata2015e.tar.gz As usual, links to the latest release files are here: http://www.iana.org/time-zones/repository/tzcode-latest.tar.gz http://www.iana.org/time-zones/repository/tzdata-latest.tar.gz ftp://ftp.iana.org/tz/tzcode-latest.tar.gz ftp://ftp.iana.org/tz/tzdata-latest.tar.gz Each release file has a GPG signature, which can be retrieved by appending ".asc" to the above URLs. Copies of these signatures are appended to this message. This release corresponds to commit 503ee68905da57fc52df74c889aedf4e67e59a79 dated Sat Jun 13 10:56:02 2015 -0700 and tagged '2015e' in the experimental github repository at <https://github.com/eggert/tz>. Here are the SHA-512 checksums for the release files: fdc568a68f4876b967b39e21fa53f063dc5756e886e2a273cc046d5a014eb517e9c91eb6e03d18c94a89ce48578868aed710790415c500188fce4e4add0ce7ca tzcode2015e.tar.gz 86498190a20c5c67827aa75f7e9c6aa6c19d58a88a70425ce70d5ae7cea42dc7386eb2867fa455fcfcdedc6a105ad70fbbdc7c27c7a58a51bd21d76a135983ce tzdata2015e.tar.gz Here are the GPG checksums for the release files: -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAABAgAGBQJVfG8zAAoJEO2X6Q5iqn4014YP/jGiiK7VYqstDoQNm33/pOwx WlwTSkzByrhx0whaaAlTQ+j61q2MdZaDlpdDd4CEGN1vWaiI26MOEbZEKVpW5ogm xKGL9esGltoc3jelmWJTVf0e03l+k0+zDcnBq+58Pi5rkgM/WVFyZBDyCT5HGLq+ NPaHLHU4dlWtwpyd9Mr4eMb6DPEM4zbTK2NbHh/uf+ODG8F1VW8FP63N/hqq4Y/q 4H+ngf9jJxw73pBri/WBmidSxLWhhc+woezhKqbCThto4Jhoehlp3txIqBmAoN3G AwppaGiHV6PYheLqloCDmdxABMoS95tznuk8eL2FF69IP541kaOchHvKCnbEf6gu Sdr388Ayli/C98ZQknwzNWVlfKKW+d+nidS5iGyEHRpI/42RPemGh5kgYmZucZpH DRIbujsi9usxjrazWC8oGf7WH6D6ZmsUusl7pj071YnU0gpXyVSk9GUoMWIp3Wxc CSHJWxF6lkxOmHDqZFHhcVyyKlPHXFpWpDUPhu/QTi7oiSQeXRoP9BQAz07oN8WS 69JUSxCvkFANkFxnx6knsDBwduFUqiZ209WwV0R72DI/7Gi6OuubXUvgcQfJOHab wOyEInI32uHRKxEaQuDmu1PSzlur0iNGH3PtuQzgwLlMM0KXsRbLBhOO5zP2BgQ6 zVgFQ9FGlnExUxsBcnTf =BRRd -----END PGP SIGNATURE----- -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAABAgAGBQJVfG8/AAoJEO2X6Q5iqn40ed0P/jn6lgG6tH+C2Xv2DYz5buRK CMDoGidznyzDuPSNgSPRaDetoKQ/6iVzEIgHYwBxBtmKmPXUgSY8rJPCabSLNKWK T3o7f8aREnIcfexmct/4DEeUOXePUIbSHnX6Noy3AmSvIsKT8ZahEpnELKgWFQD8 0EEOlck1rTTpEi9G2RATUwr430ii1OguIt0sKYycTvT1VFdihKWoFhgV9ydgaMh2 88he3Ornt4xd4/b278IJl3GI0WWVbVl2A+ziRPAkl3AH7iW7mTcv+/8i3u7txVW+ zB47UHOfV9jpiecLUQDw42KZJTlS+AkbgCitrpL++bZz1WQHWP9JkpgvAR8bdkBf WPNvcPXiG0I6Vtl2ZZrc2WXi9L22m0xIJA2so4vpBwBIMkTnaFa6VthLGy9UgHpA wteG6OogfdNm7fv+GhuRUNuHtd5TP5HdywhWMrMtGqgOvkEm/lF6tRMd12Wm57IW u72Gv3RrJILBuOvBvWPZJMNsjc8Uj1U+dhKa8Z51VHA85ZyiRM3mQr8g+1WETH/E sjnj8NgKkh7TL/N5vWJH1M3g1XZ3uofPL1Cbyqg04BGrMytxGAjigzIDbbg5pky+ yFUqR3qm12d9QPlm1xh35qxqYYDXcbiQkXENwGukLRzcc0jdU4BrFpDc1tVgukUg TmCC2ALEcxWWPEc1vtUG =gO91 -----END PGP SIGNATURE----- _______________________________________________ tz-announce mailing list tz-announce(a)iana.org https://mm.icann.org/mailman/listinfo/tz-announce

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Morocco DST Interruption during Ramadan 2015
by Milamber June 12, 2015

June 12, 2015

Hello, (Google Translation) The current time of Morocco (GMT + 1) will be suspended from next Sunday until July 19, announced Monday the Ministry of Civil Service and Modernisation of Administration. The hour will thus be delayed 60 minutes Sunday, June 14 at 3:00, the ministry said in a statement, adding that the time will be advanced again 60 minutes Sunday, July 19, 2015 at 2:00. The move comes under 2.12.126 Decree of 26 Jumada I 1433 (18 April 2012) and the decision of the Head of Government of 16 N. 3-29-15 Chaaban 1435 (4 June 2015). Source (french): http://lnt.ma/le-maroc-reculera-dune-heure-le-dimanche-14-juin/ (currently the official notice isn't publish on official government website http://www.mmsp.gov.ma) I thinks that the new rule for all new ramadan period is the time change the Sunday (like the DST) or not the Saturday. Milamber Note: Current prediction in tzdata: Africa/Casablanca Sat Jun 13 01:59:59 2015 UT = Sat Jun 13 02:59:59 2015 WEST isdst=1 gmtoff=3600 Africa/Casablanca Sat Jun 13 02:00:00 2015 UT = Sat Jun 13 02:00:00 2015 WET isdst=0 gmtoff=0 Africa/Casablanca Sat Jul 18 01:59:59 2015 UT = Sat Jul 18 01:59:59 2015 WET isdst=0 gmtoff=0 Africa/Casablanca Sat Jul 18 02:00:00 2015 UT = Sat Jul 18 03:00:00 2015 WEST isdst=1 gmtoff=3600

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Possible bug in the tz database
by Howard Hinnant June 8, 2015

June 8, 2015

I’m new to this list, so please forgive me for my inexperience and lack of history. I am concerned about the timezone America/North_Dakota/Beula: Early of the local morning of 2010-11-07 the local timezone GMTOFF changed from -7:00 to -6:00, and the timezone abbreviation changed from MDT to CST. I am not questioning this historical fact. Rather I am concerned about exactly when it happened and does the tz database accurately reflect this event. Here are the relevant entries today: Zone America/North_Dakota/Beulah -6:47:07 - LMT 1883 Nov 18 12:12:53 -7:00 US M%sT 2010 Nov 7 2:00 -6:00 US C%sT Which says at 2:00am local time on 2010/Nov/07 the change from MDT to CST occurs. Local time is defined by GMTOFF == -7:00 + US timezone rules for 2010. Or in other words 2:00am + 7:00 + any daylight savings time adjustment. I’m sure I’m preaching to the choir with this audience. I think there is no dispute that: 2010-11-07 01:59:59 MDT == 2010-11-07 07:59:59 UTC At this point in time the GMTOFF == -7:00 and in the US rule SAVE == 1:00 for a total offset of -6:00. However according to US rules for this date, the local clock ticks from 01:59:59 MDT to 01:00:00 MST. To reach 2:00am local time we need to wait another hour: 2010-11-07 02:00:00 MST == 2010-11-07 09:00:00 UTC According to US time zone rules (speaking about the recognized practice in the US, not about tz database rules), there was no 2010-11-07 02:00:00 MDT. It simply did not exist. So 2010-11-07 02:00:00 local time in US rules is unambiguously a standard time, not a daylight savings time. Whereas the times [01:00:00, 01:59:59] *are* ambiguous (or more accurately described with a half-open range: [01:00:00, 02:00:00). Since 2010-11-07 02:00:00 is unambiguously a standard time, the database could read like this with no change in behavior: Zone America/North_Dakota/Beulah -6:47:07 - LMT 1883 Nov 18 12:12:53 -7:00 US M%sT 2010 Nov 7 2:00s -6:00 US C%sT But this data indicates that local time behaves as follows that morning: 2010-11-07 01:59:59 MDT = 2010-11-07 07:59:59 UTC 2010-11-07 01:00:00 MST = 2010-11-07 08:00:00 UTC 2010-11-07 01:00:01 MST = 2010-11-07 08:00:01 UTC … 2010-11-07 01:59:59 MST = 2010-11-07 08:59:59 UTC 2010-11-07 03:00:00 CST = 2010-11-07 09:00:00 UTC 2010-11-07 03:00:01 CST = 2010-11-07 09:00:01 UTC However I believe the intended behavior is: 2010-11-07 01:59:59 MDT = 2010-11-07 07:59:59 UTC 2010-11-07 02:00:00 CST = 2010-11-07 08:00:00 UTC 2010-11-07 02:00:01 CST = 2010-11-07 08:00:01 UTC I believe the tz database can be changed to give the desired behavior with: diff --git a/northamerica b/northamerica index 88423e6..aeaf12c 100644 --- a/northamerica +++ b/northamerica @@ -371,7 +371,7 @@ Zone America/North_Dakota/New_Salem -6:45:39 - LMT 1883 Nov 18 12:14:21 # of 6h47'07". Zone America/North_Dakota/Beulah -6:47:07 - LMT 1883 Nov 18 12:12:53 - -7:00 US M%sT 2010 Nov 7 2:00 + -7:00 US M%sT 2010 Nov 7 1:00s -6:00 US C%sT # US mountain time, represented by Denver If I have misinterpreted the meanings of the fields to the tz database in some way, I would appreciate an education. I’ve reread all of the man pages and other documentation I can find, and haven’t been able to rectify this contradiction on my own. If this is indeed a bug that can be corrected, I am volunteering to detect and correct similar issues elsewhere in the database and generate a pull request for https://github.com/eggert/tz. Howard

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