- tz - lists.iana.org

Re: FW: IANA time zone registration - proposal
by Guy Harris Feb. 3, 2005

Feb. 3, 2005

Paul Eggert wrote: > However -- in case this comes up -- as far as I know we have never > relied on their case-sensitivity, and there are no plans to do so. ...which is a good thing, given that in the Olson code they're file names, and in OS X, which uses the Olson code, the files are probably going to be stored on a case-insensitive HFS+ file system. (Not that any good reason to rely on the case-sensitivity comes to mind in any case.)

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RE: FW: glibc, Linux: about the time zone transition values in th e lo calt ime file
by Fei Yuming-CYF001 Feb. 3, 2005

Feb. 3, 2005

Thank you all for the responses. Markus exactly explained the why. (In my application, I needed to get the local-broken-down-time format of the transition time point, but do NOT apply the STD/DST transition to it. The one mentioned in my previous email is the result that the DST transition has been applied to it, which was my fault. I figured out a way to fix it and get the right result.) Yuming -----Original Message----- From: Markus Kuhn [mailto:Markus.Kuhn@cl.cam.ac.uk] Sent: Thursday, February 03, 2005 11:04 AM To: Fei Yuming-CYF001 Cc: tz(a)elsie.nci.nih.gov Subject: Re: FW: glibc, Linux: about the time zone transition values in the lo calt ime file "Olson, Arthur David (NIH/NCI)" wrote on 2005-02-03 13:57 UTC: Fei Yuming <Yuming.Fei(a)motorola.com> wrote: > On Linux systems, it seems that the transitions stored in the localtime file > are not the current time to start the transition, but the new local current > time right after the transition. The following might help to clarify what I suspect you might got confused about: The transition times are stored in the "Seconds Since The Epoch (time_t)" time scale, which itself (like UTC) has *no* DST transitions. The effect you observed occured only *after* the application of the time_t->local-broken-down-time conversion, which you applied to convert the time_t value back into a human-consumable local-time yyyy-mm-dd hh:mm:ss display. It is only natural, that the transition time point itself is displayed using the same convention as the time point immediately afterwards. [By the way: This is for the same reason for which most digital clocks show 00:00 and not 24:00 at the midnight transition. Note that 24:00 would be valid only for the infinitesimal point in time at exactly midnight (and therefore invisible to the human eye), whereas 00:00 is a valid truncation until 00:01 is reached. Therefore, we use the backwards-looking notation 24:00 only when we refer to the end of a time interval (as in tonight 22:00-24:00), but not when we refer to the current time (as in "It is now 00:00.").] Markus -- Markus Kuhn, Computer Lab, Univ of Cambridge, GB http://www.cl.cam.ac.uk/~mgk25/ | __oo_O..O_oo__

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FW: glibc, Linux: about the time zone transition values in the lo calt ime file
by Olson, Arthur David (NIH/NCI) Feb. 3, 2005

Feb. 3, 2005

Yuming is not on the time zone mailing list; direct replies appropriately. --ado _____ From: Fei Yuming-CYF001 [mailto:Yuming.Fei@motorola.com] Sent: Tuesday, February 01, 2005 4:14 PM To: 'tz(a)elsie.nci.nih.gov' Subject: glibc, Linux: about the time zone transition values in the localt ime file Dear Sir: On Linux systems, it seems that the transitions stored in the localtime file are not the current time to start the transition, but the new local current time right after the transition. For example, I have the glibc-2.2.5 library on my Linux 2.4.20 system, my timezone is set to US/Central and my current time is in CST. The /etc/localtime (or /usr/share/zoneinfo/US/Central) shows that in 2005, the time to transfer into DST is 1112515200 seconds, i.e. Sun Apr 3 03:00:00 2005. (This can be got, e.g., by breaking into the glibc-2.2.5/time/tzfile.c's __tzfile_read() function, and printing out the transitions values, i.e. transitions[169] == 1112515200). However, as we know, the transition to DST is Apr 3 02:00:00 --> Apr 3 03:00:00. The time after the transition (i.e. 03:00:00) instead of the current time to start the transition (ie.. 02:00:00) has been stored in the localtime file. Could you please let me know what the reason it is to do so (i.e. why not storing 02:00:00)? I will highly appreciate your help! Yuming

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RE: glibc, Linux: about the time zone transition values in the lo calt ime file
by Olson, Arthur David (NIH/NCI) Feb. 3, 2005

Feb. 3, 2005

Here at elsie the Central time zone seems okay; witness this excerpt from the output of "zdump -v US/Central": ... US/Central Sun Apr 4 07:59:59 2004 UTC = Sun Apr 4 01:59:59 2004 CST isdst=0 US/Central Sun Apr 4 08:00:00 2004 UTC = Sun Apr 4 03:00:00 2004 CDT isdst=1 US/Central Sun Oct 31 06:59:59 2004 UTC = Sun Oct 31 01:59:59 2004 CDT isdst=1 US/Central Sun Oct 31 07:00:00 2004 UTC = Sun Oct 31 01:00:00 2004 CST isdst=0 US/Central Sun Apr 3 07:59:59 2005 UTC = Sun Apr 3 01:59:59 2005 CST isdst=0 US/Central Sun Apr 3 08:00:00 2005 UTC = Sun Apr 3 03:00:00 2005 CDT isdst=1 US/Central Sun Oct 30 06:59:59 2005 UTC = Sun Oct 30 01:59:59 2005 CDT isdst=1 US/Central Sun Oct 30 07:00:00 2005 UTC = Sun Oct 30 01:00:00 2005 CST isdst=0 US/Central Sun Apr 2 07:59:59 2006 UTC = Sun Apr 2 01:59:59 2006 CST isdst=0 US/Central Sun Apr 2 08:00:00 2006 UTC = Sun Apr 2 03:00:00 2006 CDT isdst=1 US/Central Sun Oct 29 06:59:59 2006 UTC = Sun Oct 29 01:59:59 2006 CDT isdst=1 US/Central Sun Oct 29 07:00:00 2006 UTC = Sun Oct 29 01:00:00 2006 CST isdst=0 ... --ado

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Re: Tzcode2004d.tar.gz
by Olson, Arthur David (NIH/NCI) Feb. 3, 2005

Feb. 3, 2005

The elsie copy has now been given the correct (2005) name. --ado

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Tzcode2004d.tar.gz
by Olson, Arthur David (NIH/NCI) Feb. 2, 2005

Feb. 2, 2005

The file... ftp://elsie.nci.nih.gov/pub/tzcode2004d.tar.gz ...is now available. This incorporates the (now slightly modified) changes circulated last week on the time zone mailing list to: make zic complain about links to links if the -v flag is used; have "make public" do more code checking; and add an include to "localtime.c" for the benefit of gcc systems. Note that there are no data changes. Expect one more batch of delinting changes for the code. --ado

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glibc, Linux: about the time zone transition values in the localt ime file
by Fei Yuming-CYF001 Feb. 1, 2005

Feb. 1, 2005

Dear Sir: On Linux systems, it seems that the transitions stored in the localtime file are not the current time to start the transition, but the new local current time right after the transition. For example, I have the glibc-2.2.5 library on my Linux 2.4.20 system, my timezone is set to US/Central and my current time is in CST. The /etc/localtime (or /usr/share/zoneinfo/US/Central) shows that in 2005, the time to transfer into DST is 1112515200 seconds, i.e. Sun Apr 3 03:00:00 2005. (This can be got, e.g., by breaking into the glibc-2.2.5/time/tzfile.c's __tzfile_read() function, and printing out the transitions values, i.e. transitions[169] == 1112515200). However, as we know, the transition to DST is Apr 3 02:00:00 --> Apr 3 03:00:00. The time after the transition (i.e. 03:00:00) instead of the current time to start the transition (ie.. 02:00:00) has been stored in the localtime file. Could you please let me know what the reason it is to do so (i.e. why not storing 02:00:00)? I will highly appreciate your help! Yuming

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Time Zones 1914
by Hall, Jr., Owen Jan. 29, 2005

Jan. 29, 2005

Hi, I am doing some research on the Goeben during August 4 - 8, 1914. Do you know the time zone for Rome and Messina during this period? Today they are GMT +1. Thanks in advance. Professor Hall

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Time in Ireland
by Joseph S. Myers Jan. 26, 2005

Jan. 26, 2005

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Proposed changes to localtime.c, zic.c, and Makefile
by Olson, Arthur David (NIH/NCI) Jan. 24, 2005

Jan. 24, 2005

Here are proposed changes to: 1. localtime.c, to include "float.h" for the benefit of some gcc systems (thanks to Bradley White for finding the problem). 2. zic.c, to complain about links to links if the "-v" flag is used. 3. Makefile, to ensure that a "make public" is done with the benefit of gcc diagnostics. --ado ------- localtime.c ------- *** /tmp/geta15164 Mon Jan 24 12:20:36 2005 --- /tmp/getb15164 Mon Jan 24 12:20:36 2005 *************** *** 5,11 **** #ifndef lint #ifndef NOID ! static char elsieid[] = "@(#)localtime.c 7.89"; #endif /* !defined NOID */ #endif /* !defined lint */ --- 5,11 ---- #ifndef lint #ifndef NOID ! static char elsieid[] = "@(#)localtime.c 7.90"; #endif /* !defined NOID */ #endif /* !defined lint */ *************** *** 20,25 **** --- 20,26 ---- #include "private.h" #include "tzfile.h" #include "fcntl.h" + #include "float.h" /* for FLT_MAX and DBL_MAX */ /* ** SunOS 4.1.1 headers lack O_BINARY. ------- zic.c ------- *** /tmp/geta15183 Mon Jan 24 12:20:47 2005 --- /tmp/getb15183 Mon Jan 24 12:20:47 2005 *************** *** 1,4 **** ! static char elsieid[] = "@(#)zic.c 7.118"; /* ** Regardless of the type of time_t, we do our work using this type. --- 1,4 ---- ! static char elsieid[] = "@(#)zic.c 7.119"; /* ** Regardless of the type of time_t, we do our work using this type. *************** *** 579,584 **** --- 579,589 ---- for (i = 0; i < nlinks; ++i) { eat(links[i].l_filename, links[i].l_linenum); dolink(links[i].l_from, links[i].l_to); + if (noise) + for (j = 0; j < nlinks; ++j) + if (strcmp(links[i].l_to, + links[j].l_from) == 0) + warning("link to link"); } if (lcltime != NULL) { eat("command line", 1); ------- Makefile ------- *** /tmp/geta15240 Mon Jan 24 12:21:57 2005 --- /tmp/getb15240 Mon Jan 24 12:21:57 2005 *************** *** 1,4 **** ! # @(#)Makefile 7.103 # Change the line below for your time zone (after finding the zone you want in # the time zone files, or adding it to a time zone file). --- 1,4 ---- ! # @(#)Makefile 7.104 # Change the line below for your time zone (after finding the zone you want in # the time zone files, or adding it to a time zone file). *************** *** 384,390 **** # The zics below ensure that each data file can stand on its own. ! public: $(ENCHILADA) zic -mkdir /tmp/,tzpublic -for i in $(TDATA) ; do zic -v -d /tmp/,tzpublic $$i 2>&1 | grep -v "starting year" ; done for i in $(TDATA) ; do zic -d /tmp/,tzpublic $$i || exit; done --- 384,392 ---- # The zics below ensure that each data file can stand on its own. ! public: ! make maintainer-clean ! make "CFLAGS=$(GCC_DEBUG_FLAGS)" -mkdir /tmp/,tzpublic -for i in $(TDATA) ; do zic -v -d /tmp/,tzpublic $$i 2>&1 | grep -v "starting year" ; done for i in $(TDATA) ; do zic -d /tmp/,tzpublic $$i || exit; done

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