- tz - lists.iana.org

Re: Message to `tz' mailing list
by Robert Elz Feb. 19, 2006

Feb. 19, 2006

Date: Fri, 17 Feb 2006 15:14:09 +0530 From: "N. Raghavendra" <raghu(a)mri.ernet.in> Message-ID: <867j7ugw0m.fsf(a)riemann.mri.ernet.in> | Perhaps I did not express my question clearly. I am trying to | understand how, given | | 1. an integer TIME (viewed as a number of seconds since the Epoch); | and | | 2. a TZFILE, | | one computes the wall clock time corresponding to TIME, in the time | zone defined by TZFILE. The wall clock time should be returned as a | broken-down time value, i.e., as a list of the form | | (SEC, MIN, HOUR, MDAY, MON, YEAR, WDAY, IS_DST, TZ_ABBREV, GMT_OFF) That's exactly what localtime() does isn't it? All the code is available (and free to use) - just use it (either the learn from, or simply to compile into your application). The raw tzfile isn't used of course, it is converted (using zic) into a binary format - but if you needed to you could combine the roles of zic and localtime into one function. kre

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RE: Message to `tz' mailing list
by Olson, Arthur David (NIH/NCI) [E] Feb. 17, 2006

Feb. 17, 2006

> I am confused about the use of the UTC/local indicators and the standard/wall indicators in a tzfile. According to tzfile(5), they "are used when > a time zone file is used in handling POSIX-style time zone environment variables". Does this mean that these indicators are irrelevant when computing > local time using only a tzfile (without looking at the environment). That's correct: the ttisgmt and ttisstd indicators can be ignored if you're simply trying to figure out what wall clock time is for the zone that's associated with the file. (The indicators are there for the case when the time zone file is used as a "template" for the DST rules to be used when handling POSIX-style TZ environment variables; you need to know whether the transition time is defined in terms of UTC, local wall clock time, or local standard time to be able to know when translating the transition time for use in another zone.) --ado

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Proposed tz code cleanups
by Arthur David Olson Feb. 16, 2006

Feb. 16, 2006

Along with the 64-bit changes previously circulated on the time zone list and due to show up in the ftp version on Monday, here are proposed STDC, long, and overflow cleanups from Paul Eggert and Ken Pizzini. diff -r -c old/date.c new/date.c *** old/date.c Thu Jan 26 10:19:21 2006 --- new/date.c Thu Feb 16 11:05:15 2006 *************** *** 1,6 **** #ifndef lint #ifndef NOID ! static char elsieid[] = "@(#)date.c 7.42"; /* ** Modified from the UCB version with the SCCS ID appearing below. */ --- 1,6 ---- #ifndef lint #ifndef NOID ! static char elsieid[] = "@(#)date.c 7.44"; /* ** Modified from the UCB version with the SCCS ID appearing below. */ *************** *** 254,260 **** struct timeval tv; tv.tv_sec = (int) adjust; ! tv.tv_usec = (int) ((adjust - tv.tv_sec) * 1000000); if (adjtime(&tv, (struct timeval *) NULL) != 0) oops("adjtime"); #endif /* HAVE_ADJTIME */ --- 254,260 ---- struct timeval tv; tv.tv_sec = (int) adjust; ! tv.tv_usec = (int) ((adjust - tv.tv_sec) * 1000000L); if (adjtime(&tv, (struct timeval *) NULL) != 0) oops("adjtime"); #endif /* HAVE_ADJTIME */ *************** *** 352,360 **** --- 352,364 ---- /*ARGSUSED*/ static void + #ifdef __STDC__ + reset(const time_t newt, const int nflag) + #else /* !defined __STDC__ */ reset(newt, nflag) const time_t newt; const int nflag; + #endif /* !defined __STDC__ */ { register int fid; time_t oldt; *************** *** 619,628 **** --- 623,636 ---- #define ATOI2(ar) (ar[0] - '0') * 10 + (ar[1] - '0'); ar += 2; static time_t + #ifdef __STDC__ + convert(register const char * const value, const int dousg, const time_t t) + #else /* !defined __STDC__ */ convert(value, dousg, t) register const char * const value; const int dousg; const time_t t; + #endif /* !defined __STDC__ */ { register const char * cp; register const char * dotp; *************** *** 726,736 **** --- 734,751 ---- */ static void + #ifdef __STDC__ + checkfinal(const char * const value, + const int didusg, + const time_t t, + const time_t oldnow) + #else /* !defined __STDC__ */ checkfinal(value, didusg, t, oldnow) const char * const value; const int didusg; const time_t t; const time_t oldnow; + #endif /* !defined __STDC__ */ { time_t othert; struct tm tm; *************** *** 789,799 **** --- 804,819 ---- } static void + #ifdef __STDC__ + iffy(const time_t thist, const time_t thatt, + const char * const value, const char * const reason) + #else /* !defined __STDC__ */ iffy(thist, thatt, value, reason) const time_t thist; const time_t thatt; const char * const value; const char * const reason; + #endif /* !defined __STDC__ */ { struct tm tm; diff -r -c old/localtime.c new/localtime.c *** old/localtime.c Thu Jan 26 10:19:21 2006 --- new/localtime.c Thu Feb 16 11:07:47 2006 *************** *** 5,11 **** #ifndef lint #ifndef NOID ! static char elsieid[] = "@(#)localtime.c 7.97"; #endif /* !defined NOID */ #endif /* !defined lint */ --- 5,11 ---- #ifndef lint #ifndef NOID ! static char elsieid[] = "@(#)localtime.c 7.98"; #endif /* !defined NOID */ #endif /* !defined lint */ *************** *** 510,518 **** --- 510,522 ---- */ static const char * + #ifdef __STDC__ + getqzname(register const char *strp, const char delim) + #else /* !defined __STDC__ */ getqzname(strp, delim) register const char * strp; const char delim; + #endif /* !defined __STDC__ */ { register char c; diff -r -c old/zdump.c new/zdump.c *** old/zdump.c Thu Jan 26 10:19:21 2006 --- new/zdump.c Thu Feb 16 11:16:58 2006 *************** *** 1,4 **** ! static char elsieid[] = "@(#)zdump.c 7.74"; /* ** This code has been made independent of the rest of the time --- 1,4 ---- ! static char elsieid[] = "@(#)zdump.c 7.76"; /* ** This code has been made independent of the rest of the time *************** *** 15,21 **** #include "ctype.h" /* for isalpha et al. */ #ifndef isascii #define isascii(x) 1 ! #endif #ifndef ZDUMP_LO_YEAR #define ZDUMP_LO_YEAR (-500) --- 15,21 ---- #include "ctype.h" /* for isalpha et al. */ #ifndef isascii #define isascii(x) 1 ! #endif /* !defined isascii */ #ifndef ZDUMP_LO_YEAR #define ZDUMP_LO_YEAR (-500) *************** *** 418,431 **** } } else if (0 > (time_t) -1) { /* ! ** time_t is signed. */ ! register time_t hibit; ! for (hibit = 1; (hibit * 2) != 0; hibit *= 2) ! continue; ! absolute_min_time = hibit; ! absolute_max_time = -(hibit + 1); } else { /* ** time_t is unsigned. --- 418,438 ---- } } else if (0 > (time_t) -1) { /* ! ** time_t is signed. Assume overflow wraps around. */ ! time_t t = 0; ! time_t t1 = 1; ! while (t < t1) { ! t = t1; ! t1 = 2 * t1 + 1; ! } ! ! absolute_max_time = t; ! t = -t; ! absolute_min_time = t - 1; ! if (t < absolute_min_time) ! absolute_min_time = t; } else { /* ** time_t is unsigned. *************** *** 468,477 **** --- 475,488 ---- } static time_t + #ifdef __STDC__ + hunt(char *name, time_t lot, time_t hit) + #else /* !defined __STDC__ */ hunt(name, lot, hit) char * name; time_t lot; time_t hit; + #endif /* !defined __STDC__ */ { time_t t; long diff; *************** *** 541,550 **** --- 552,565 ---- } static void + #ifdef __STDC__ + show(char *zone, time_t t, int v) + #else /* !defined __STDC__ */ show(zone, t, v) char * zone; time_t t; int v; + #endif /* !defined __STDC__ */ { register struct tm * tmp;

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FW: Message to `tz' mailing list
by Olson, Arthur David (NIH/NCI) [E] Feb. 16, 2006

Feb. 16, 2006

N. Raghavendra has been added to the time zone mailing list. --ado -----Original Message----- From: N. Raghavendra [mailto:raghu@mri.ernet.in] Sent: Wednesday, February 15, 2006 11:44 AM To: Olson, Arthur David (NIH/NCI) [E] Subject: Message to `tz' mailing list ... UTC and std indicators: I am trying to write a Common Lisp program to compute local time using the `tz' database. I am confused about the use of the UTC/local indicators and the standard/wall indicators in a tzfile. According to tzfile(5), they "are used when a time zone file is used in handling POSIX-style time zone environment variables". Does this mean that these indicators are irrelevant when computing local time using only a tzfile (without looking at the environment). I have tried reading `localtime.c' using my negligible knowledge of C, but haven't understood the role of the indicators. Any pointers on this would be most welcome. TIA, Raghavendra. -- N. Raghavendra <raghu(a)mri.ernet.in> | See message headers for contact Harish-Chandra Research Institute | and OpenPGP details.

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RE: America/Edmonton 2007
by Paul Schauble Feb. 11, 2006

Feb. 11, 2006

In cases like this I really have to wonder about the custom of using the largest city. To me, it makes much more sense to name the entity to which the change applies. Not just whatever city happens to be there. Naming the province, county, state, or whatever terms the changes applies to conveys more information. In this case, I think that should be America/Alberta or America/Canada/Alberta. In some the recent Indiana things, I think the tz name should have been America/Indiana/county. And I still think it should be America/Navajo, not America/Shiprock. Thanks for your attention, ++PLS -----Original Message----- From: tz-request(a)elsie.nci.nih.gov [mailto:tz-request@elsie.nci.nih.gov] On Behalf Of Chris Walton-TM Sent: Tuesday, February 07, 2006 2:53 PM To: tz(a)lecserver.nci.nih.gov Subject: FW: America/Edmonton 2007 -----Original Message----- From: Chris Walton-TM Sent: February 7, 2006 1:42 AM To: tz(a)lecserver.nci.nih.gov Subject: America/Edmonton 2007 The Alberta government announced on Feb 2 that it will extend daylight savings by four weeks starting in 2007. This will match the changes that have been made in the United States. I am hoping that "America/Edmonton" can be updated in the next tzdata release. Here is a link from the CBC website. http://www.cbc.ca/calgary/story/ca_daylight20060202.html Thanks. -chris

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RE: Pulaski County rebels against the Department of Transportation
by Olson, Arthur David (NIH/NCI) [E] Feb. 9, 2006

Feb. 9, 2006

We're faced with the ugly possibility that clocks will be set two different ways in Pulaski County; offices under federal control (such as post offices) may follow U. S. Department of Transportation regulations. Particularly touchy: any federal court offices located in Pulaski County. --ado -----Original Message----- From: Paul Eggert [mailto:eggert@cs.ucla.edu] Sent: Wednesday, February 08, 2006 4:15 AM To: tz(a)lecserver.nci.nih.gov Subject: Pulaski County rebels against the Department of Transportation According to an AP article <http://www.indystar.com/apps/pbcs.dll/article?AID=/20060207/NEWS01/6020 70408/1006>, officials in Pulaski County, Indiana, have changed their minds, and want to undo the time-zone change that they asked the feds to grant a few months ago. "While it's official, it's unofficial: We will not set our clocks with Chicago; we'll set our clocks with Indianapolis," said Pulaski County Council President Sam Frain. Even if they follow through with this threat, we won't have to create a new zone; Pulaski County residents can continue to use the America/Indiana/Indianapolis zone. However, we should adjust zone.tab and the comments to make it clear that Pulaski County is still using Indianapolis time.

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RE: America/Edmonton 2007
by Olson, Arthur David (NIH/NCI) [E] Feb. 9, 2006

Feb. 9, 2006

One piece of evidence from the current Indiana brouhaha: > According to an AP article > <http://www.indystar.com/apps/pbcs.dll/article?AID=/20060207/NEWS01/6020 70408/1006>, > officials in Pulaski County, Indiana, have changed their minds, and want to undo the time-zone change that they asked the feds to grant a few months > ago. "While it's official, it's unofficial: We will not set our clocks with Chicago; we'll set our clocks with Indianapolis," > said Pulaski County Council President Sam Frain. Citizen Frain uses cities (rather than counties or states) to describe what Pulaski is to do. --ado

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RE: America/Edmonton and other zone naming issues
by Paul Schauble Feb. 8, 2006

Feb. 8, 2006

We actually might be able to do that in the US. As far as I know, all of these zone changes are done by country. The only exceptions I know of in the states where incorporated cities are more or less equivalent to counties. So we might have America/Indiana/Pulaski Pulaski County America/Arizona America/Navajo Navajo reservation, or America/Dineh If we made links for America/<State>/<Jurisdiction> to whatever was right, we would cover 99.9% of these changes without people needing to change the name they use. <Jurisdiction> is usually county, but could be an incorporated city or an indian nation, or a few other things. I think the real need, though, is to tie the zone name to the jurisdiction making the change, and not to pick an arbitrary city as a proxy for the deciding jurisdiction. Where an entire state follows the same rules, don't create the county level. Just for reference, the US has 3,007 entities named "County" 16 Boroughs in Alaska 11 Census Areas in Alaska (for areas not organized into Boroughs by the State) 64 Parishes in Louisiana 42 Independent Cities (1 in Maryland, 1 in Missouri, 1 in Nevada, and the remainder in Virginia) 1 District - the Federal District or District of Columbia. -----Original Message----- From: tz-request(a)elsie.nci.nih.gov [mailto:tz-request@elsie.nci.nih.gov] On Behalf Of Mark Davis Sent: Wednesday, February 08, 2006 8:23 AM To: tz(a)lecserver.nci.nih.gov Cc: tz(a)lecserver.nci.nih.gov Subject: Re: America/Edmonton and other zone naming issues What would be even better would be physical boundaries for each given zone. Right now, within multi-zone countries, the timezone database alone is insufficient to determine the behavior of any given city (or other location). Mark

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Pulaski County rebels against the Department of Transportation
by Paul Eggert Feb. 8, 2006

Feb. 8, 2006

According to an AP article <http://www.indystar.com/apps/pbcs.dll/article?AID=/20060207/NEWS01/60207040…>, officials in Pulaski County, Indiana, have changed their minds, and want to undo the time-zone change that they asked the feds to grant a few months ago. "While it's official, it's unofficial: We will not set our clocks with Chicago; we'll set our clocks with Indianapolis," said Pulaski County Council President Sam Frain. Even if they follow through with this threat, we won't have to create a new zone; Pulaski County residents can continue to use the America/Indiana/Indianapolis zone. However, we should adjust zone.tab and the comments to make it clear that Pulaski County is still using Indianapolis time.

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FW: America/Edmonton 2007
by Chris Walton-TM Feb. 8, 2006

Feb. 8, 2006

-----Original Message----- From: Chris Walton-TM Sent: February 7, 2006 1:42 AM To: tz(a)lecserver.nci.nih.gov Subject: America/Edmonton 2007 The Alberta government announced on Feb 2 that it will extend daylight savings by four weeks starting in 2007. This will match the changes that have been made in the United States. I am hoping that "America/Edmonton" can be updated in the next tzdata release. Here is a link from the CBC website. http://www.cbc.ca/calgary/story/ca_daylight20060202.html Thanks. -chris

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