- tz - lists.iana.org

Identifying timezones ...
by Lester Caine June 3, 2016

June 3, 2016

I feel it's worth pointing out something which seems to have got lost during the current discussion ... The shorthand abbreviation for a offset may or may not indicate that a time is affected by daylight savings. Taking the simple example of 'BST' which is an abbreviation that has a sort of statutory definition in the 'British Summer Time' laws, one knows that there is a related start and stop date and so adding a couple of weeks delay may also require a change of offset, but if the same date is posted as 'GMT' there is no information that 'BST' changes are relevant. I get the impression that with all of the current upheaval in Russia that some areas are introducing daylight saving, while others are standardising on one or other of an 'abbreviation' without the matching switch? The ONLY ident that correctly provides the correct time sequence. both current and historic is the full name, but even that now gets tricky with the improving accuracy of pre 1970 data? This new data either needs it's own 'shorthand', or we do need to drop the shorthand! If one is doing the job of providing a date and time which must sit accurately in an historic context, then the 'local' offset from UTC has to be stored as the timezone name and VERSION of tz used. Simply using 'EST' is of no use what so ever, while just using 'Asia/Tomsk' falls flat on it's face when you don't know which rules were active then the timestamp was stored. In my book the only clean way of managing historic data is to maintain a UTC normalised timestamp along with the location data to provide a local time. If an event occurs that casts doubt on the offset then a new UTC time may needed, and it's the identified change that flags up the advise that needs to accompany the notification. On current calendars that may well be that Ramadan is a week early or late, but the 'abbreviations' used do not necessarily change as a result? They are just a piece of text accompanying the rule which should actually be a translated note from the rule set since abbreviations may not be unique. -- Lester Caine - G8HFL ----------------------------- Contact - http://lsces.co.uk/wiki/?page=contact L.S.Caine Electronic Services - http://lsces.co.uk EnquirySolve - http://enquirysolve.com/ Model Engineers Digital Workshop - http://medw.co.uk Rainbow Digital Media - http://rainbowdigitalmedia.co.uk

1 0

Re: [tz] YouTube videos on time zones
by Steve Jones May 30, 2016

May 30, 2016

At 01:14 PM 3/8/2016, Matt Johnson wrote: >If these two aren't in our art file, they probably should be. One mustn't forget the trailer for "Daylight Saving", the movie: https://www.youtube.com/watch?v=k4EUTMPuvHo Regards, Steve Jones

3 2

New time zone library
by Matt Johnson May 29, 2016

May 29, 2016

Please add to the tz-link file under Other tz compilers: Lau's Tzdata library for the Elixir language automatically downloads and compiles tz source data, and exposes APIs for use. It is freely available under the MIT license. https://github.com/lau/tzdata Thanks, Matt

2 1

[PROPOSED PATCH] * zic.c: Update comments for Qt and GNOME bugs.
by Paul Eggert May 29, 2016

May 29, 2016

--- zic.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/zic.c b/zic.c index 2284d2c..3eb65d3 100644 --- a/zic.c +++ b/zic.c @@ -143,11 +143,11 @@ static bool yearistype(int year, const char * type); /* Bound on length of what %z can expand to. */ enum { PERCENT_Z_LEN_BOUND = sizeof "+995959" - 1 }; -/* If true, work around a bug in Qt 5.6 and earlier, which mishandles +/* If true, work around a bug in Qt 5.6.1 and earlier, which mishandles tzdata binary files whose POSIX-TZ-style strings contain '<'; see QTBUG-53071 <https://bugreports.qt.io/browse/QTBUG-53071>. This - workaround will no longer be needed when Qt 5.6 is obsolete, say in - the year 2021. */ + workaround will no longer be needed when Qt 5.6.1 and earlier are + obsolete, say in the year 2021. */ enum { WORK_AROUND_QTBUG_53071 = true }; static int charcnt; @@ -880,7 +880,11 @@ static zic_t const max_time = MAXVAL (zic_t, TIME_T_BITS_IN_FILE); /* If true, work around GNOME bug 730332 <https://bugzilla.gnome.org/show_bug.cgi?id=730332> by refusing to output time stamps before BIG_BANG. - Such time stamps are physically suspect anyway. */ + Such time stamps are physically suspect anyway. + + The GNOME bug is scheduled to be fixed in GNOME 3.22, and if so + this workaround will no longer be needed when GNOME 3.21 and + earlier are obsolete, say in the year 2021. */ enum { WORK_AROUND_GNOME_BUG_730332 = true }; static const zic_t early_time = (WORK_AROUND_GNOME_BUG_730332 -- 2.5.5

1 0

[PROPOSED PATCH] Switch from 'zzz' to '-00' for uninhabited abbr
by Paul Eggert May 29, 2016

May 29, 2016

* NEWS, Theory, tz-how-to.html: Document this. * antarctica (Antarctica/Casey, Antarctica/Davis) (Antarctica/Mawson, Indian/Kerguelen, Antarctica/DumontDUrville): (Antarctica/Syowa, Antarctica/Troll, Antarctica/Vostok) (Antarctica/Rothera): * australasia (Antarctica/Macquarie): * backzone (Antarctica/McMurdo): * northamerica (America/Pangnirtung, America/Iqaluit) (America/Resolute, America/Rankin_Inlet, America/Cambridge_Bay) (America/Yellowknife, America/Inuvik): * southamerica (Antarctica/Palmer): Use '-00', not 'zzz', to abbreviate UT in uninhabited locations. --- NEWS | 7 +++++++ Theory | 7 ++++--- antarctica | 24 ++++++++++++------------ australasia | 4 ++-- backzone | 2 +- northamerica | 14 +++++++------- southamerica | 2 +- tz-how-to.html | 16 ++++++++++------ 8 files changed, 44 insertions(+), 32 deletions(-) diff --git a/NEWS b/NEWS index b5fb182..54a520d 100644 --- a/NEWS +++ b/NEWS @@ -11,6 +11,13 @@ Unreleased, experimental changes Changes affecting past time stamps + Locations while uninhabited now use '-00', not 'zzz', as a + placeholder time zone abbreviation. This is inspired by Internet + RFC 3339 and is more consistent with numeric time zone + abbreviations already used elsewhere. The change affects several + arctic and antarctic locations, e.g., America/Cambridge_Bay before + 1920 and Antarctica/Troll before 2005. + Asia/Baku's 1992-09-27 transition from +04 (DST) to +04 (non-DST) was at 03:00, not 23:00 the previous day. (Thanks to Michael Deckers.) diff --git a/Theory b/Theory index 6bed91f..60678fe 100644 --- a/Theory +++ b/Theory @@ -227,9 +227,10 @@ in decreasing order of importance: name identifying each zone and append 'T', 'ST', etc. as before; e.g. 'VLAST' for VLAdivostok Summer Time. - Use UT (with time zone abbreviation 'zzz') for locations while - uninhabited. The 'zzz' mnemonic is that these locations are, - in some sense, asleep. + Use UT (with time zone abbreviation '-00') for locations while + uninhabited. The leading '-' is a flag that the time + zone is in some sense undefined; this notation is + derived from Internet RFC 3339. Application writers should note that these abbreviations are ambiguous in practice: e.g. 'CST' has a different meaning in China than diff --git a/antarctica b/antarctica index 2af088f..a537832 100644 --- a/antarctica +++ b/antarctica @@ -13,7 +13,7 @@ # # Except for the French entries, # I made up all time zone abbreviations mentioned here; corrections welcome! -# FORMAT is 'zzz' and GMTOFF is 0 for locations while uninhabited. +# FORMAT is '-00' and GMTOFF is 0 for locations while uninhabited. # Argentina - year-round bases # Belgrano II, Confin Coast, -770227-0343737, since 1972-02-05 @@ -67,22 +67,22 @@ # http://www.timeanddate.com/news/time/antartica-time-changes-2010.html # Zone NAME GMTOFF RULES FORMAT [UNTIL] -Zone Antarctica/Casey 0 - zzz 1969 +Zone Antarctica/Casey 0 - -00 1969 8:00 - AWST 2009 Oct 18 2:00 # Australian Western Std Time 11:00 - CAST 2010 Mar 5 2:00 # Casey Time 8:00 - AWST 2011 Oct 28 2:00 11:00 - CAST 2012 Feb 21 17:00u 8:00 - AWST -Zone Antarctica/Davis 0 - zzz 1957 Jan 13 +Zone Antarctica/Davis 0 - -00 1957 Jan 13 7:00 - DAVT 1964 Nov # Davis Time - 0 - zzz 1969 Feb + 0 - -00 1969 Feb 7:00 - DAVT 2009 Oct 18 2:00 5:00 - DAVT 2010 Mar 10 20:00u 7:00 - DAVT 2011 Oct 28 2:00 5:00 - DAVT 2012 Feb 21 20:00u 7:00 - DAVT -Zone Antarctica/Mawson 0 - zzz 1954 Feb 13 +Zone Antarctica/Mawson 0 - -00 1954 Feb 13 6:00 - MAWT 2009 Oct 18 2:00 # Mawson Time 5:00 - MAWT # References: @@ -137,7 +137,7 @@ Zone Antarctica/Mawson 0 - zzz 1954 Feb 13 # fishing stations operated variously 1819/1931 # # Zone NAME GMTOFF RULES FORMAT [UNTIL] -Zone Indian/Kerguelen 0 - zzz 1950 # Port-aux-Français +Zone Indian/Kerguelen 0 - -00 1950 # Port-aux-Français 5:00 - TFT # ISO code TF Time # # year-round base in the main continent @@ -148,9 +148,9 @@ Zone Indian/Kerguelen 0 - zzz 1950 # Port-aux-Français # It was destroyed by fire on 1952-01-14. # # Zone NAME GMTOFF RULES FORMAT [UNTIL] -Zone Antarctica/DumontDUrville 0 - zzz 1947 +Zone Antarctica/DumontDUrville 0 - -00 1947 10:00 - PMT 1952 Jan 14 # Port-Martin Time - 0 - zzz 1956 Nov + 0 - -00 1956 Nov 10:00 - DDUT # Dumont-d'Urville Time # France & Italy - year-round base @@ -176,7 +176,7 @@ Zone Antarctica/DumontDUrville 0 - zzz 1947 # was established on 1957-01-29. Since Syowa station is still the main # station of Japan, it's appropriate for the principal location. # Zone NAME GMTOFF RULES FORMAT [UNTIL] -Zone Antarctica/Syowa 0 - zzz 1957 Jan 29 +Zone Antarctica/Syowa 0 - -00 1957 Jan 29 3:00 - SYOT # Syowa Time # See: # NIPR Antarctic Research Activities (1999-08-17) @@ -226,7 +226,7 @@ Rule Troll 2005 max - Mar lastSun 1:00u 2:00 CEST # Remove the following line when uncommenting the above '#Rule' lines. Rule Troll 2004 max - Oct lastSun 1:00u 0:00 UTC # Zone NAME GMTOFF RULES FORMAT [UNTIL] -Zone Antarctica/Troll 0 - zzz 2005 Feb 12 +Zone Antarctica/Troll 0 - -00 2005 Feb 12 0:00 Troll %s # Poland - year-round base @@ -267,7 +267,7 @@ Zone Antarctica/Troll 0 - zzz 2005 Feb 12 # happened to be during their visit. So we still don't really know what time # it is at Vostok. But we'll guess UTC+6. # -Zone Antarctica/Vostok 0 - zzz 1957 Dec 16 +Zone Antarctica/Vostok 0 - -00 1957 Dec 16 6:00 - VOST # Vostok time # S Africa - year-round bases @@ -300,7 +300,7 @@ Zone Antarctica/Vostok 0 - zzz 1957 Dec 16 # <http://webexhibits.org/daylightsaving/g.html> says Rothera is -03 all year. # # Zone NAME GMTOFF RULES FORMAT [UNTIL] -Zone Antarctica/Rothera 0 - zzz 1976 Dec 1 +Zone Antarctica/Rothera 0 - -00 1976 Dec 1 -3:00 - ROTT # Rothera time # Uruguay - year round base diff --git a/australasia b/australasia index 55f44cf..0b33f67 100644 --- a/australasia +++ b/australasia @@ -243,11 +243,11 @@ Zone Australia/Lord_Howe 10:36:20 - LMT 1895 Feb # will produce a binary file with an [A]EST-type as the first 32-bit type; # this is required for correct handling of times before 1916 by # pre-2013 versions of localtime. -Zone Antarctica/Macquarie 0 - zzz 1899 Nov +Zone Antarctica/Macquarie 0 - -00 1899 Nov 10:00 - AEST 1916 Oct 1 2:00 10:00 1:00 AEDT 1917 Feb 10:00 Aus AE%sT 1919 Apr 1 0:00s - 0 - zzz 1948 Mar 25 + 0 - -00 1948 Mar 25 10:00 Aus AE%sT 1967 10:00 AT AE%sT 2010 Apr 4 3:00 11:00 - MIST # Macquarie I Standard Time diff --git a/backzone b/backzone index 296eca8..13dc8d4 100644 --- a/backzone +++ b/backzone @@ -395,7 +395,7 @@ Zone America/Tortola -4:18:28 - LMT 1911 Jul # Road Town -4:00 - AST # McMurdo, Ross Island, since 1955-12 -Zone Antarctica/McMurdo 0 - zzz 1956 +Zone Antarctica/McMurdo 0 - -00 1956 12:00 NZ NZ%sT Link Antarctica/McMurdo Antarctica/South_Pole diff --git a/northamerica b/northamerica index 1d7395c..6256f97 100644 --- a/northamerica +++ b/northamerica @@ -2191,39 +2191,39 @@ Rule NT_YK 1980 2006 - Oct lastSun 2:00 0 S Rule NT_YK 1987 2006 - Apr Sun>=1 2:00 1:00 D # Zone NAME GMTOFF RULES FORMAT [UNTIL] # aka Panniqtuuq -Zone America/Pangnirtung 0 - zzz 1921 # trading post est. +Zone America/Pangnirtung 0 - -00 1921 # trading post est. -4:00 NT_YK A%sT 1995 Apr Sun>=1 2:00 -5:00 Canada E%sT 1999 Oct 31 2:00 -6:00 Canada C%sT 2000 Oct 29 2:00 -5:00 Canada E%sT # formerly Frobisher Bay -Zone America/Iqaluit 0 - zzz 1942 Aug # Frobisher Bay est. +Zone America/Iqaluit 0 - -00 1942 Aug # Frobisher Bay est. -5:00 NT_YK E%sT 1999 Oct 31 2:00 -6:00 Canada C%sT 2000 Oct 29 2:00 -5:00 Canada E%sT # aka Qausuittuq -Zone America/Resolute 0 - zzz 1947 Aug 31 # Resolute founded +Zone America/Resolute 0 - -00 1947 Aug 31 # Resolute founded -6:00 NT_YK C%sT 2000 Oct 29 2:00 -5:00 - EST 2001 Apr 1 3:00 -6:00 Canada C%sT 2006 Oct 29 2:00 -5:00 - EST 2007 Mar 11 3:00 -6:00 Canada C%sT # aka Kangiqiniq -Zone America/Rankin_Inlet 0 - zzz 1957 # Rankin Inlet founded +Zone America/Rankin_Inlet 0 - -00 1957 # Rankin Inlet founded -6:00 NT_YK C%sT 2000 Oct 29 2:00 -5:00 - EST 2001 Apr 1 3:00 -6:00 Canada C%sT # aka Iqaluktuuttiaq -Zone America/Cambridge_Bay 0 - zzz 1920 # trading post est.? +Zone America/Cambridge_Bay 0 - -00 1920 # trading post est.? -7:00 NT_YK M%sT 1999 Oct 31 2:00 -6:00 Canada C%sT 2000 Oct 29 2:00 -5:00 - EST 2000 Nov 5 0:00 -6:00 - CST 2001 Apr 1 3:00 -7:00 Canada M%sT -Zone America/Yellowknife 0 - zzz 1935 # Yellowknife founded? +Zone America/Yellowknife 0 - -00 1935 # Yellowknife founded? -7:00 NT_YK M%sT 1980 -7:00 Canada M%sT -Zone America/Inuvik 0 - zzz 1953 # Inuvik founded +Zone America/Inuvik 0 - -00 1953 # Inuvik founded -8:00 NT_YK P%sT 1979 Apr lastSun 2:00 -7:00 NT_YK M%sT 1980 -7:00 Canada M%sT diff --git a/southamerica b/southamerica index fb437b2..1c38f63 100644 --- a/southamerica +++ b/southamerica @@ -1309,7 +1309,7 @@ Zone Pacific/Easter -7:17:28 - LMT 1890 # Palmer used to be supplied from Argentina. # # Zone NAME GMTOFF RULES FORMAT [UNTIL] -Zone Antarctica/Palmer 0 - zzz 1965 +Zone Antarctica/Palmer 0 - -00 1965 -4:00 Arg AR%sT 1969 Oct 5 -3:00 Arg AR%sT 1982 May -4:00 Chile CL%sT diff --git a/tz-how-to.html b/tz-how-to.html index 3fa7602..f0fedc5 100644 --- a/tz-how-to.html +++ b/tz-how-to.html @@ -466,13 +466,11 @@ offset, so the wall clock time during this period was GMT − 10:30 + 1:00 = GMT − 9:30. The <code>FORMAT</code> column specifies the usual abbreviation of -the time zone name. It can have one of four forms: +the time zone name. It can have one of three forms: <ul> -<li>the string, “<code>zzz</code>,” which is a kind of -null value (don’t ask)</li> - -<li>a single alphabetic string other than “<code>zzz</code>,” +<li>a string of three or more characters that are either ASCII alphanumerics, +“<code>+</code>”, or “<code>-</code>”, in which case that’s the abbreviation</li> <li>a pair of strings separated by a slash @@ -513,7 +511,7 @@ a <code>SAVE</code> of zero. </ul> -And two last things about the <code>FORMAT</code> column: +And three last things about the <code>FORMAT</code> column: <ul> <li>The <a href="https://en.wikipedia.org/wiki/Tz_database">tz @@ -535,6 +533,12 @@ the abbreviations. They are intended to be the values returned through the <a href="http://pubs.opengroup.org/onlinepubs/9699919799/functions/strftime.html"><code>strftime</code></a> function in the <a href="http://www.chemie.fu-berlin.de/chemnet/use/info/libc/libc_19.html#SEC324">“C” locale</a>. + +<li>If there is no generally-accepted abbreviation for a time zone, +a numeric offset is used instead, e.g., <code>+07</code> for 7 hours +ahead of Greenwich. By convention, <code>-00</code> stands for an +zone while uninhabited, where the offset is zero but in some sense +the true offset is undefined. </ul> As a final example, here’s the complete history for Hawaii: -- 2.5.5

1 0

[PROPOSED PATCH] Fix "-"s in zic man page with Bell Labs troff
by Paul Eggert May 29, 2016

May 29, 2016

* zic.8: Fix a typo in defining \*- when using traditional troff. --- zic.8 | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/zic.8 b/zic.8 index 94b6753..e5e71f5 100644 --- a/zic.8 +++ b/zic.8 @@ -26,7 +26,7 @@ zic \- time zone compiler .\} .el \{\ . ds : -. el ds - \- +. ds - \- .\} .I Zic reads text from the file(s) named on the command line -- 2.5.5

1 0

efele.net/tz maps updated for 2016d
by Eric Muller May 28, 2016

May 28, 2016

1 0

Morocco rule to suspend DST for RAMADAN
by BENNANI RHITA May 28, 2016

May 28, 2016

Hi, We are facing again a small change on the period for which Morocco will suspend DST. The rule actually applied on our system is : Morocco will temporarily switch to standard time at 03:00 the last Saturday before Ramadan, and back to DST at 02:00 the first Saturday after Ramadan. While in fact and according to the latest official decree the temporary DST suspension is as below : Morocco will temporarily switch to standard time at 03:00 the last Sunday before Ramadan, and back to DST at 02:00 the first Sunday after Ramadan. So Morocco will suspend DST from 2016-06-05 03:00 through 2016-07-10 02:00, not 06-04 and 07-09 as guessed. Is there a way to update the TZupdater in order to correct this. We really need to update it before 1st of June in order to publish our schedules correctly for the days 06-04 and 07-10. Thanks a lot, Best regards [Description : cid:image001.png@01D010AD.0526CD40] BENNANI Rhita Chef de Projet Département Commercial et Exploitation Direction Organisation et Systèmes d'Information +212 522 91 22 36 www.royalairmaroc.com<http://www.royalairmaroc.com/> [Description : cid:image001.jpg@01D01561.B1BD0430] <http://www.facebook.com/RoyalAirMaroc> [Description : cid:image002.jpg@01D01561.B1BD0430] <https://twitter.com/RAM_Maroc> [Description : cid:image003.jpg@01D01561.B1BD0430] <https://plus.google.com/116698608481885525601> [Description : Description : cid:image005.png@01D00B0B.40B7FD90]

3 3

Anecdotal discrepancy for Navajo nation in Arizona
by Deborah Goldsmith May 26, 2016

May 26, 2016

Hi, A colleague recently visited Page, Arizona, and the Navajo reservation right next to it. His phone must have been associated with a cell tower inside the Navajo nation, because his zone was set by NITZ to America/Denver (DST in effect). This matches the current TZ database. However, he observed that the parts of the Navajo nation adjacent to Page were actually observing the same time zone as Page (America/Phoenix, DST not in effect). I wouldn’t make any changes based on this one anecdote, but it might be worth checking if anyone has any sources inside the Navajo nation. Thanks, Debbie

8 12

Re: [tz] Asia/Tomsk
by vanadovv＠hetnet.nl May 26, 2016

May 26, 2016

>----Origineel Bericht---- >Van : guy(a)alum.mit.edu >Datum : 26/05/2016 11:08 >Aan : vas(a)mpeks.tomsk.su >Cc : tz(a)iana.org >Onderwerp : Re: [tz] Asia/Tomsk > >On May 25, 2016, at 10:19 AM, Victor Sudakov <vas(a)mpeks.tomsk.su> wrote: > >> As a member of the public, I don't like the idea of the tz project >> calling my time zone <+07> :-) > >As a member of the tzdb project (albeit one whose main effort was ages ago), I don't like the idea of expecting people not necessarily from the locale of a tzdb zone to pick abbreviations for times in the zone and then deal with complaints from people from that locale. :-) > My reply: Look at the law: the official time zone name for Tomsk is: 6-я часовая зона (If utf-8 is working, then you'll see Russian in Cyrillic letters.) The English translation is: 6th hourly zone (6th timezone). Cheerio! Oscar van Vlijmen

4 5