June 2012 - tz - lists.iana.org

proposed time zone package changes (Samoa, Factory, et al.)
by Arthur David Olson 28 Aug '19

28 Aug '19

Below find proposed time zone package changes; the executive summary: * Makefile Change LOCALTIME default from "Factory" to "GMT"; do not compile "factory" file (but keep it in the distribution). * Theory Remove reference to "Factory" zone. * australasia Change end of DST in Samoa in 2011 from 2011-04-03 0:00 to 2011-04-03 1:00 (thanks to Raymond Hughes for a reference). * localtime.c Initialize ttinfo structures filled by tzparse (thanks to Ravindra for reporting a valgrind warning). * zic.c Fix generation of POSIX strings for zones with rules using "weekday<=n" forms of dates (thanks to Lei Liu for finding the problem). Also, limit output for non-POSIX-specificable zones defined to follow the same rules every year. (Note that no zones of either of the above types appear in the distribution; these changes cater to add-on zones). If no problems are found, 2010n will appear on 2010-10-25. --ado diff -r -c old/Makefile new/Makefile *** old/Makefile Mon Sep 27 09:24:25 2010 --- new/Makefile Tue Oct 12 12:36:50 2010 *************** *** 1,5 **** # <pre> ! # @(#)Makefile 8.8 # This file is in the public domain, so clarified as of # 2009-05-17 by Arthur David Olson. --- 1,5 ---- # <pre> ! # @(#)Makefile 8.9 # This file is in the public domain, so clarified as of # 2009-05-17 by Arthur David Olson. *************** *** 12,18 **** # make zonenames # to get a list of the values you can use for LOCALTIME. ! LOCALTIME= Factory # If you want something other than Eastern United States time as a template # for handling POSIX-style time zone environment variables, --- 12,18 ---- # make zonenames # to get a list of the values you can use for LOCALTIME. ! LOCALTIME= GMT # If you want something other than Eastern United States time as a template # for handling POSIX-style time zone environment variables, *************** *** 262,269 **** DOCS= README Theory $(MANS) date.1 Makefile PRIMARY_YDATA= africa antarctica asia australasia \ europe northamerica southamerica ! YDATA= $(PRIMARY_YDATA) pacificnew etcetera factory backward ! NDATA= systemv SDATA= solar87 solar88 solar89 TDATA= $(YDATA) $(NDATA) $(SDATA) TABDATA= iso3166.tab zone.tab --- 262,269 ---- DOCS= README Theory $(MANS) date.1 Makefile PRIMARY_YDATA= africa antarctica asia australasia \ europe northamerica southamerica ! YDATA= $(PRIMARY_YDATA) pacificnew etcetera backward ! NDATA= systemv factory SDATA= solar87 solar88 solar89 TDATA= $(YDATA) $(NDATA) $(SDATA) TABDATA= iso3166.tab zone.tab diff -r -c old/Theory new/Theory *** old/Theory Mon Sep 27 09:24:25 2010 --- new/Theory Tue Oct 12 12:36:50 2010 *************** *** 1,4 **** ! @(#)Theory 8.4 This file is in the public domain, so clarified as of 2009-05-17 by Arthur David Olson. --- 1,4 ---- ! @(#)Theory 8.5 This file is in the public domain, so clarified as of 2009-05-17 by Arthur David Olson. *************** *** 287,294 **** See the file `backward' for most of these older names (e.g. `US/Eastern' instead of `America/New_York'). The other old-fashioned names still supported are ! `WET', `CET', `MET', `EET' (see the file `europe'), ! and `Factory' (see the file `factory'). ----- Time zone abbreviations ----- --- 287,293 ---- See the file `backward' for most of these older names (e.g. `US/Eastern' instead of `America/New_York'). The other old-fashioned names still supported are ! `WET', `CET', `MET', and `EET' (see the file `europe'). ----- Time zone abbreviations ----- diff -r -c old/australasia new/australasia *** old/australasia Mon Sep 27 09:24:27 2010 --- new/australasia Tue Oct 12 13:14:56 2010 *************** *** 1,5 **** # <pre> ! # @(#)australasia 8.18 # This file is in the public domain, so clarified as of # 2009-05-17 by Arthur David Olson. --- 1,5 ---- # <pre> ! # @(#)australasia 8.19 # This file is in the public domain, so clarified as of # 2009-05-17 by Arthur David Olson. *************** *** 487,497 **** # http://www.parliament.gov.ws/documents/acts/Daylight%20Saving%20Act%20%2020… # </a> Zone Pacific/Apia 12:33:04 - LMT 1879 Jul 5 -11:26:56 - LMT 1911 -11:30 - SAMT 1950 # Samoa Time -11:00 - WST 2010 Sep 26 ! -11:00 1:00 WSDT 2011 Apr 3 -11:00 - WST # Solomon Is --- 487,507 ---- # http://www.parliament.gov.ws/documents/acts/Daylight%20Saving%20Act%20%2020… # </a> + # From Raymond Hughes (2010-10-07): + # Please see + # <a href="http://www.mcil.gov.ws"> + # http://www.mcil.gov.ws + # </a>, + # the Ministry of Commerce, Industry and Labour (sideframe) "Last Sunday + # September 2010 (26/09/10) - adjust clocks forward from 12:00 midnight + # to 01:00am and First Sunday April 2011 (03/04/11) - adjust clocks + # backwards from 1:00am to 12:00am" + Zone Pacific/Apia 12:33:04 - LMT 1879 Jul 5 -11:26:56 - LMT 1911 -11:30 - SAMT 1950 # Samoa Time -11:00 - WST 2010 Sep 26 ! -11:00 1:00 WSDT 2011 Apr 3 1:00 -11:00 - WST # Solomon Is diff -r -c old/localtime.c new/localtime.c *** old/localtime.c Mon Sep 27 09:24:26 2010 --- new/localtime.c Tue Oct 12 12:36:51 2010 *************** *** 5,11 **** #ifndef lint #ifndef NOID ! static char elsieid[] = "@(#)localtime.c 8.14"; #endif /* !defined NOID */ #endif /* !defined lint */ --- 5,11 ---- #ifndef lint #ifndef NOID ! static char elsieid[] = "@(#)localtime.c 8.15"; #endif /* !defined NOID */ #endif /* !defined lint */ *************** *** 914,919 **** --- 914,920 ---- register unsigned char * typep; register char * cp; register int load_result; + static struct ttinfo zttinfo; INITIALIZE(dstname); stdname = name; *************** *** 986,991 **** --- 987,993 ---- /* ** Two transitions per year, from EPOCH_YEAR forward. */ + sp->ttis[0] = sp->ttis[1] = zttinfo; sp->ttis[0].tt_gmtoff = -dstoffset; sp->ttis[0].tt_isdst = 1; sp->ttis[0].tt_abbrind = stdlen + 1; *************** *** 1099,1106 **** } /* ** Finally, fill in ttis. - ** ttisstd and ttisgmt need not be handled. */ sp->ttis[0].tt_gmtoff = -stdoffset; sp->ttis[0].tt_isdst = FALSE; sp->ttis[0].tt_abbrind = 0; --- 1101,1108 ---- } /* ** Finally, fill in ttis. */ + sp->ttis[0] = sp->ttis[1] = zttinfo; sp->ttis[0].tt_gmtoff = -stdoffset; sp->ttis[0].tt_isdst = FALSE; sp->ttis[0].tt_abbrind = 0; *************** *** 1113,1118 **** --- 1115,1121 ---- dstlen = 0; sp->typecnt = 1; /* only standard time */ sp->timecnt = 0; + sp->ttis[0] = zttinfo; sp->ttis[0].tt_gmtoff = -stdoffset; sp->ttis[0].tt_isdst = 0; sp->ttis[0].tt_abbrind = 0; diff -r -c old/zic.c new/zic.c *** old/zic.c Mon Sep 27 09:24:26 2010 --- new/zic.c Tue Oct 12 13:37:29 2010 *************** *** 3,9 **** ** 2006-07-17 by Arthur David Olson. */ ! static char elsieid[] = "@(#)zic.c 8.22"; #include "private.h" #include "locale.h" --- 3,9 ---- ** 2006-07-17 by Arthur David Olson. */ ! static char elsieid[] = "@(#)zic.c 8.24"; #include "private.h" #include "locale.h" *************** *** 1881,1896 **** register int week; if (rp->r_dycode == DC_DOWGEQ) { ! week = 1 + rp->r_dayofmonth / DAYSPERWEEK; ! if ((week - 1) * DAYSPERWEEK + 1 != rp->r_dayofmonth) return -1; } else if (rp->r_dycode == DC_DOWLEQ) { if (rp->r_dayofmonth == len_months[1][rp->r_month]) week = 5; else { ! week = 1 + rp->r_dayofmonth / DAYSPERWEEK; ! if (week * DAYSPERWEEK - 1 != rp->r_dayofmonth) return -1; } } else return -1; /* "cannot happen" */ (void) sprintf(result, "M%d.%d.%d", --- 1881,1896 ---- register int week; if (rp->r_dycode == DC_DOWGEQ) { ! if ((rp->r_dayofmonth % DAYSPERWEEK) != 1) return -1; + week = 1 + rp->r_dayofmonth / DAYSPERWEEK; } else if (rp->r_dycode == DC_DOWLEQ) { if (rp->r_dayofmonth == len_months[1][rp->r_month]) week = 5; else { ! if ((rp->r_dayofmonth % DAYSPERWEEK) != 0) return -1; + week = rp->r_dayofmonth / DAYSPERWEEK; } } else return -1; /* "cannot happen" */ (void) sprintf(result, "M%d.%d.%d", *************** *** 2018,2023 **** --- 2018,2024 ---- register char * envvar; register int max_abbr_len; register int max_envvar_len; + register int prodstic; /* all rules are min to max */ max_abbr_len = 2 + max_format_len + max_abbrvar_len; max_envvar_len = 2 * max_abbr_len + 5 * 9; *************** *** 2032,2037 **** --- 2033,2039 ---- timecnt = 0; typecnt = 0; charcnt = 0; + prodstic = zonecount == 1; /* ** Thanks to Earl Chew ** for noting the need to unconditionally initialize startttisstd. *************** *** 2053,2058 **** --- 2055,2062 ---- updateminmax(rp->r_loyear); if (rp->r_hiwasnum) updateminmax(rp->r_hiyear); + if (rp->r_lowasnum || rp->r_hiwasnum) + prodstic = FALSE; } } /* *************** *** 2075,2080 **** --- 2079,2094 ---- if (max_year <= INT_MAX - YEARSPERREPEAT) max_year += YEARSPERREPEAT; else max_year = INT_MAX; + /* + ** Regardless of any of the above, + ** for a "proDSTic" zone which specifies that its rules + ** always have and always will be in effect, + ** we only need one cycle to define the zone. + */ + if (prodstic) { + min_year = 1900; + max_year = min_year + YEARSPERREPEAT; + } } /* ** For the benefit of older systems,

5 6

proposed tz change for Latvia, Lithuania
by Paul Eggert 25 May '15

25 May '15

It's March Madness time for daylight-saving rule changes. Here's a proposed change to the tz database to keep up with the latest political development, which affects time stamps starting March 29: * Latvia and Lithuania will not observe DST, starting this year. Thanks to Andrei Ivanov for this info. =================================================================== RCS file: RCS/europe,v retrieving revision 2000.3 retrieving revision 2000.3.0.1 diff -pu -r2000.3 -r2000.3.0.1 --- europe 2000/03/04 15:31:08 2000.3 +++ europe 2000/03/08 17:48:59 2000.3.0.1 @@ -1135,6 +1135,12 @@ Link Europe/Rome Europe/San_Marino # 1997-01-21 on transition to Summer time ... established the same order of # daylight savings time settings as in the States of the European Union. +# From Andrei Ivanov (2000-03-06): +# This year Latvia will not switch to Daylight Savings Time (as specified in +# <a href="http://www.lv-laiks.lv/wwwraksti/2000/071072/vd4.htm"> +# The Regulations of the Cabinet of Ministers of the Rep. of Latvia of +# 29-Feb-2000 (#79)</a>, in Latvian for subscribers only). + # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S Rule Latvia 1989 1996 - Mar lastSun 2:00s 1:00 S Rule Latvia 1989 1996 - Sep lastSun 2:00s 0 - @@ -1151,7 +1157,8 @@ Zone Europe/Riga 1:36:24 - LMT 1880 3:00 Russia MSK/MSD 1989 Mar lastSun 2:00s 2:00 1:00 EEST 1989 Sep lastSun 2:00s 2:00 Latvia EE%sT 1997 Jan 21 - 2:00 EU EE%sT + 2:00 EU EE%sT 2000 Feb 29 + 2:00 - EET # Liechtenstein # Zone NAME GMTOFF RULES FORMAT [UNTIL] @@ -1178,6 +1185,11 @@ Zone Europe/Vaduz 0:38:04 - LMT 1894 Jun # motion to give up shifting to summer time in spring, as it was # already done by Estonia. +# From Andrei Ivanov (2000-03-06): +# I've heard that Ministers of three Baltic countries on their summit +# somewhere in February decided not to switch to summer time starting from +# this spring. + # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Europe/Vilnius 1:41:16 - LMT 1880 1:24:00 - WMT 1917 # Warsaw Mean Time @@ -1192,7 +1204,8 @@ Zone Europe/Vilnius 1:41:16 - LMT 1880 2:00 C-Eur EE%sT 1998 2:00 - EET 1998 Mar 29 1:00u 1:00 EU CE%sT 1999 Oct 31 1:00u - 2:00 EU EE%sT + 2:00 EU EE%sT 2000 Feb + 2:00 - EET # Luxembourg # Whitman disagrees with most of these dates in minor ways; go with Shanks.

5 5

Adding Asia/Beijing timezone into the database
by Daoming Qiu 06 Dec '14

06 Dec '14

"Beijing Time" is the standard time used for China region, so it is very strange that tzdatabase doesn't have timezone called Asia/Beijing. Strongly suggest to add "Asia/Beijing" zone into the database, and its information is very similar with "Asia/Shanghai".

14 17

a patch for zic.c to allow 'follow rules'
by Alois Treindl 10 Sep '13

10 Sep '13

Dear Arthur, I have been preparing a small modification for zic.c which will allow it to understand a 'follow rule' in zone files, like this: # experimental table for Geneva, to test the 'follow' mechanism Zone Europe/Geneva 0:24:37 - LMT 1848 Sep 12 0:24:37 - GET 1894 Jun # Geneva MTime 0 follow Europe/Zurich For test purposes, one can simply insert this zone in the europe file. The feature is helpful in the extension of tzdata to cover complete timezone history. For this purpose, about 1000 additional zone files need to be written, and to be maintained. The process to do so has started in the astrological community, as it needs a complete pre-1970 timezone history. I will not bother you with details. I intend to help creating and maintaining a set of files like 'europe_hist', 'asia_hist' etc which contain the additional zones. The 'follow rule' will allow to keep these extra zone files very small, as usually the additional zones will all have a cross-over moment into a regular tzdata zone. I have for the moment called the modified zic source file zicx.c and prepared a patch file for zic.c to implement the 'follow rule' feature. I have tried to keep the modification very small. Please have a look at the patch, and check for the errors I have probably made. Description of the code: ------------------------ The follow rule must be the last line in a zone, and recursion is not allowed. It is parsed in inzsub() which reacts on GMTOFF = 0 and the word 'follow' in the RULE field. The zone line is stored in zones[] with a special value z_gmtoff = FOLLOW_MARK and the zone_name to follow in field z_rule (which is abused for this purpose). Before the call to outzone() the two sets of zone lines are patched together in a temporary array, so that outzone() and all functions deeper down() need not be modified. Patch ----- --- zic.c 2011-03-09 20:41:27.000000000 +0100 +++ zicx.c 2011-08-25 16:09:04.000000000 +0200 @@ -262,6 +262,17 @@ static int typecnt; #define YR_MAXIMUM 1 #define YR_ONLY 2 +/* +** follow rules, added by Alois Treindl August 2011 +** Zones may end with a line: 0 follow zone_name +** which the parser will represent with FOLLOW_MARK in z_gmtoff, +** and the zone name in z_rule. +** Before the call to outzone() the zone and its follow zone will be +** patched together, so that outzone() sees a regular zone array. +** To keep zone files readable, follow rules cannot be used recursively. +*/ +#define FOLLOW_MARK 999999 + static struct rule * rules; static int nrules; /* number of rules */ @@ -589,7 +600,48 @@ _("%s: More than one -L option specified */ for (j = i + 1; j < nzones && zones[j].z_name == NULL; ++j) continue; - outzone(&zones[i], j - i); + if (zones[j -1].z_gmtoff == FOLLOW_MARK) { + /* copy zone and follow zone into one new array */ + int k,n,m, nrows; + struct zone *xzones, *zp; + nrows = j - i - 1; + zp = &zones[j - 1]; /* line with the follow rule */ + xzones = (struct zone *) (void *) emalloc((int) (nrows * sizeof *xzones)); + for (k = 0; k < nrows; k++) + xzones[k] = zones[i + k]; + /* now find the follow zone in array zones[] */ + for (m = 0; m < nzones; m++) { + if (zones[m].z_name != NULL && strcmp(zp->z_rule, zones[m].z_name) == 0) break; + } + if (m == nzones) { /* error, follow zone not found */ + char *cp; + cp = emalloc(80 + strlen(zp->z_rule) + strlen(zones[i].z_name));; + sprintf(cp, "For zone %s follow zone %s not found, no zonefile created.", zones[i].z_name, zp->z_rule); + eat(zp->z_filename, zp->z_linenum); + error(cp); + ifree(cp); + ifree((void *)xzones); + } + /* now find the next date in the follow zone */ + for (n = m + 1; n < nzones; n++) { + if (zp->z_untiltime < zones[n].z_untiltime) break; + } + /* missing errorcode for case n == nzones, + * assume we are still in same follow zone. + * The follow zone part we need starts at zones[n]. + * Now find where follow zone ends, will be m. + */ + for (m = n; m < nzones && zones[m].z_name == NULL; ++m) + continue; + xzones = (struct zone *) (void *) erealloc((char *) xzones, (int) ((nrows + m - n) * sizeof *xzones)); + for (k = 0; k < m - n; k++) + xzones[nrows + k] = zones[n + k]; + nrows += m - n; + outzone(&xzones[0], nrows); + ifree((void *) xzones); + } else { + outzone(&zones[i], j - i); + } } /* ** Make links. @@ -784,7 +836,7 @@ associate(void) } for (i = 0; i < nzones; ++i) { zp = &zones[i]; - if (zp->z_nrules == 0) { + if (zp->z_nrules == 0 && zp->z_gmtoff != FOLLOW_MARK) { /* ** Maybe we have a local standard time offset. */ @@ -1079,11 +1131,23 @@ const int iscont; return FALSE; } } - z.z_rule = ecpyalloc(fields[i_rule]); - z.z_format = ecpyalloc(fields[i_format]); - if (max_format_len < strlen(z.z_format)) - max_format_len = strlen(z.z_format); - hasuntil = nfields > i_untilyear; + /* check for 0 follow zonename + ** zonename must contain at least one /, and follow must be + * 'follow' or an abbreviation thereof. + */ + if (z.z_gmtoff == 0 && strchr(fields[i_format], '/') != NULL + && itsabbr(fields[i_rule], "follow")) { + z.z_gmtoff = FOLLOW_MARK; + z.z_rule = ecpyalloc(fields[i_format]); + z.z_format = ""; + hasuntil = FALSE; /* no continue of zone now */ + } else { + z.z_rule = ecpyalloc(fields[i_rule]); + z.z_format = ecpyalloc(fields[i_format]); + if (max_format_len < strlen(z.z_format)) + max_format_len = strlen(z.z_format); + hasuntil = nfields > i_untilyear; + } if (hasuntil) { z.z_untilrule.r_filename = filename; z.z_untilrule.r_linenum = linenum;

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Russia may move it's clocks back 1 or 2 hours
by Alexander Krivenyshev 28 Jun '12

28 Jun '12

According to different news (in Russian), Russian State Duma is considering the introduction of a permanent winter time with moving its clocks back 1-2 hours. The bill on the transition from summer to winter time will be finalized and submitted to Russian State Duma in early September. http://www.worldtimezone.com/dst_news/dst_news_russia44.html Alexander Krivenyshev, http://www.worldtimezone.com

1 0

Coordinates for America/Sitka in zone.tab?
by OvV_HN 26 Jun '12

26 Jun '12

In reply to: [tz] Coordinates for America/Sitka in zone.tab? Alan Mintz Alan_Mintz+TZ_IANA at Earthlink.net Tue Jun 26 07:26:52 UTC 2012 I was under the impression, from the few that I look at on a map, that the coordinates in zone.tab were supposed to be approximately where the name of the zone and the most well-known place is. America/Sitka puzzles me, though. At 57 10 35, -135 18 07, the point is in the water of Katlian Bay, about 150m offshore of a seemingly uninhabited area. The point is 14 km from Sitka. Should this be changed to 57d03'06", -135d20'19"? Reply: Your reference? The Geonames server: http://www.geonames.org/search.html?q=sitka&country=US says: United States, Alaska Sitka City and Borough seat of a second-order administrative division population 8,881, elevation 8m N 57° 3' 11'', W 135° 19' 48'' Which seems better than a place with wet feet! So, please change zone.tab someday..... Oscar van Vlijmen

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Coordinates for America/Sitka in zone.tab?
by Alan Mintz 26 Jun '12

26 Jun '12

I was under the impression, from the few that I look at on a map, that the coordinates in zone.tab were supposed to be approximately where the name of the zone and the most well-known place is. America/Sitka puzzles me, though. At 57 10 35, -135 18 07, the point is in the water of Katlian Bay, about 150m offshore of a seemingly uninhabited area. The point is 14 km from Sitka. Should this be changed to 57d03'06", -135d20'19"? -- Alan Mintz <Alan_Mintz+TZ_IANA(a)Earthlink.net>

1 0

Bug report: "Asia" timezone
by Boruch Baum 19 Jun '12

19 Jun '12

I was recently showing off ... and I entered the following command $ date && TZ=Asia/Moscow date Tue Jun 19 15:48:14 EDT 2012 Tue Jun 19 19:48:14 Asia 2012 My initial reaction, besides some embarrassment at getting the continent wrong (and most of Russia's timezone are in Asia), is that this is a bug in the coreutils date command. However, I thought it would be of interest to members of the list. It's a double bug. It's printing out a non-existent timezone, and it's using GMT for "Asia" -- hkp://keys.gnupg.net CA45 09B5 5351 7C11 A9D1 7286 0036 9E45 1595 8BC0

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tz abbreviations / zdump for programmers
by Boruch Baum 19 Jun '12

19 Jun '12

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Greetings y'all, I have a bit of a long (inaugural) post here to describe my interest in joining this list, and what I might be able to contribute to the greater glory of tz-correctness. BTW, as part of my 'due diligence' before posting this, I read/scanned a selection of the collection of detailed comments in the glibc-2.13/timezone files, as well as the timezone entry in glibc-2.13/FAQ. I'm very glad those comments are there. CONTENTS ======== 1] The app/library I develop/maintain 2] End users' stubborn insistence on using tz abbreviations 2.1] zone.tab modification proposal 2.2] zone.abbr.tab proposal 3] The 'zdump' programmer's function I 'need' to write 1] The app/library I develop/maintain ===================================== libhdate is a FOSS collection for Hebrew time/date 'stuff', for which time zone data and location coordinates are important because: 1) we have about a dozen significant astronomical times-of-day that need to be mapped to a correct local clock time at any particular location; 2) users want that information for future and past dates, and; 3) users want that information for locations in other parts of the globe. This FOSS collection is under active development and versions are available from sourceforge and the Debian GNU/Linux repositories. There are unrelated, closed-source, alternatives available (eg. kaluach for windows and java, and dostagfarlinux for, um, linux). 2] End users' stubborn insistence on using tz abbreviations =========================================================== ... and who can blame them, when that's all they hear in the media. This leaves me in a bind, because if I accept a tz abbreviation as a user input, I have two undesirable options: 1) I could scan ALL the ~420 tzif files for matches and, if I discover that the tz abbrev is not unique, either make an educated guess (based upon the user's locale definition which often will include a country code and a language) or prompt the user for clarification; or 2) I could pre-compile a list that suits my parochial needs, and update my list anytime the tzdata package is updated (and still have to occassionally guess or prompt the user). Then I said to myself, "self, you can't be the only one out there facing these users - go consult and find a global solution". Following are two proposals. Neither may be perfect, but each may make life alot easier for many... 2.1] zone.tab modification proposal =================================== Add a new column/field to this file, in the format: {{;xxx:nnnnn;xxx:nnnnn;...;}} where: xxx is a tz abbreviation nnnnn is the UTC offset for that abbreviation. The use of ";", ":", and braces are to simplify the task of parsing the data programmatically. Advantages: 1) All information for a timezone on a single line (ie. in a single record). 2) All worldwide information in a single file (no need to travel the dir-tree and parse ~420 files) Disadvantages: 1) Long line(record) length 2) Messing with the format of an existing file, upon which others may depend 3) Requires change to whatever script/program is used to compile the file for release 2.2] zone.abbr.tab proposal =========================== Create a new text file, say /usr/share/zoneinfo/zone.abbr.tab, sorted by tz abbreviation, with a format like: tz_abbrev country_code localedef useful for setting $LC_TIME and for language matching is_dst if yes, this would have the abbreviation of the non_dst version of this tz. utc_offset historical_only (y/n) - ie. whether currently in use. full_name of the abbreviation, not of the 'real' tz name. Advantages: 1) Easy to find matches for users' pesky (short and convenient-to-type) tz_abbr 2) All worldwide information in a single file (no need to travel the dir-tree and parse ~420 files) 3) Includes additional useful information (is_dst, historical_only, full_name, locale_def) 4) Doesn't mess with existing files Disadvantages: 1) It's a new file. 2) Requires new script/program to compile the file for release 3] The 'zdump' programmer's functiion I 'need' to write ======================================================= This section isn't directly related to the above. I don't NEED to write a 'zdump' programmer's functiion; I WANT to, because I remember when a 4Mhz clock speed was wicked fast, and using the current glibc time functions for my libhdate collection would be tremendously wasteful, although today's users will probably never notice. For this section, the reason I want to consult with members of this list (and I appreciate you having read this far) is to make the function as universally useful as possible (it will be FOSS/GPL3+) . My current plan is: int zdump( /// returns TRUE on success, FALSE on failure const char* tzname, /// fully-qualified time-zone name /// (eg. Asia/Baku) const time_t start, /// seconds from epoch to be scanned const time_t end, /// seconds from epoch to be scanned int* num_entries, /// upon successful return, int will contain /// the number of dst transitions + 1, /// for the interval 'start' to 'end'. /// The first entry will always be the /// tz state at time_t start. /// Returns 0 on failure. void* return_data /// upon successful return, will contain a pointer to a malloc()ed space of /// 'num_entries' of 'tzinfo' data, as /// described below, sorted in ascending /// chronological order. /// Returns NULL on failure. ) tzinfo { time_t start /// seconds from epoch int utc_offset /// in minutes, or maybe seconds. char is_dst /// 0/1 char[] tz_abbrev /// const char end_mark /// '\0' } - -- hkp://keys.gnupg.net CA45 09B5 5351 7C11 A9D1 7286 0036 9E45 1595 8BC0 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJPzM3HAAoJEDvrUfDmCx9LbJ4P/RMD+8KWkXxrLtpivyQVz6Yv h88mWjwfeTpb7laT4yeg726YYUQEDfhueLFELRTpxR6aAIAW7fBZEu6UwEMSsxHe UaQdx/xc/03aei/AG6z31u0C+arA40qs8twxEw5pdyHfvBxhQh0YOxO+dl01+zmg w4Y+Mlyd72QmAZ+pdIc5l2L/nTh9L+YnlmPxsXoomYSTh+9kigOxS5JZVMu2sYy6 7FGMj+mybrtru12qwJmoFG2hNjVgy0zKSuJ1HOXmqi5JKBNthlsfkyV4E9vzSGWC PkkbI8R0adGnqKa9faHQxFG+jV+K5Fjscr3eabBi8IYHG+cGYOL6vD0KkNFbHRQf wLRGpkkMjoJm9cxJ7f17wcQFtYFKjcDLIqqtDuT7LhHJ7iF2x4lTqd4YjvpA6rqN fcD+4TNfm8Na5bNbKNJqvWy+Od46wSNqFOiUf9NQaWsUZx/yiXjw1Sl4Jqi7/2Sg A3rc2bcw02Co80bWA+lsMbZUL5NJlQAdfWCKe7xafdILX8PPbe0CaTHzNUFd4vR9 70AJsq6teBivVHossldNlQfsK+S4HmcSMGPt1AuANjGUv0ZoCveR71Ewt0D2wbi4 hSEaSI/P3MVSsFRMJZIoMXlFTuF6d6qItoRvmHrLdU2u5f1+Kjbt7tH0eMOrcdm9 BUi/N3QtrJkU6vWXjLal =n4Kd -----END PGP SIGNATURE-----

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Re: [tz] Are these valid timezone definitions?
by Tadashi Abe 15 Jun '12

15 Jun '12

Hi, sorry to interrupt with newbie question. david singleton wrote: >When I define a timezone with export >TZ="NZST-12:00:00NZDT-13:00:00,M10.1.0,M3.3.0" >there is no change in time when daylight savings ends. > >Is this a known problem? Or a problem with how the timezones are defined? Now I'm testing DST start/end by setting the actual system clock as same as the above method and get the same issue. 1. export TZ="NZST-12:00:00NZDT-13:00:00,M10.1.0,M3.3.0" 2. set system clock just 5 seconds prior to DST [start|end] 3. 5 seconds later, check if switch between DST and STD occurs, but not. As the comment from Zefram, it works when I check date with -d option. http://mm.icann.org/pipermail/tz/2012-June/018059.html >It's always difficult to test timezone offset issues when you're >stating the test times in local time. By the way, your testing method >of modifying the system clock is problematic. It's much better to use >the -d option of GNU date to display a particular time without touching >the clock. Why doesn't it work well when I try to test by modifying the actual system clock? -- Tadashi Abe

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