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mktime() failure vs 31-DEC-1969 23:59:59 GMT
by tomp＠zk3.dec.com Feb. 14, 1996

Feb. 14, 1996

This has probably been discussed before, but perhaps someone can bring me up to speed. The standards for mktime() define a return value of (time_t)-1 as indicating that the time specified cannot be represented. However, a return value of -1 is also a valid time_t corresponding to 31-DEC-1969 23:59:59 GMT. How do we distinguish between the two? Here's a sample program: #include <time.h> #include <strings.h> #include <string.h> #include <stdio.h> main() { struct tm stm; time_t timet; memset(&stm, 0, sizeof(stm)); putenv("TZ=GMT0"); stm.tm_sec = 59; stm.tm_min = 59; stm.tm_hour = 23; stm.tm_mday = 31; stm.tm_mon = 11; stm.tm_year = 69; stm.tm_isdst = -1; timet = mktime(&stm); printf("timet = %ld\n",timet); } thanks, - Tom

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Re: tztab changes for HPUX
by ado Feb. 12, 1996

Feb. 12, 1996

Current versions of the public-domain time zone package do the right thing for October, 1995: Script started on Mon Feb 12 10:53:47 1996 elsie$ ./zdump -v Europe/London | grep 1995 Europe/London Sun Mar 26 00:59:59 1995 GMT = Sun Mar 26 00:59:59 1995 GMT isdst=0 Europe/London Sun Mar 26 01:00:00 1995 GMT = Sun Mar 26 02:00:00 1995 BST isdst=1 Europe/London Sun Oct 22 00:59:59 1995 GMT = Sun Oct 22 01:59:59 1995 BST isdst=1 Europe/London Sun Oct 22 01:00:00 1995 GMT = Sun Oct 22 01:00:00 1995 GMT isdst=0 elsie$ exit script done on Mon Feb 12 10:54:36 1996 Howmsoever...the references to and excerpts from "tztab" files in the articles about HPUX indicate the existence of an alternate and (presumably better) way of handling time zone stuff. If anyone has tztab insights to share with folks on the list, I'd love it. --ado

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tzcode96d.tar.gz and tzdata96c.tar.gz
by ado Feb. 12, 1996

Feb. 12, 1996

Updated time zone files are available using anonymous ftp from elsie.nci.nih.gov (165.112.73.1) in the ~ftp/pub directory: -rw-r--r-- 1 ado 73315 Feb 12 11:05 tzcode96d.tar.gz -rw-r--r-- 1 ado 73301 Feb 12 11:05 tzdata96c.tar.gz The "code" file simply updates Bob Kridle's electronic address; the "data" file updates rules for Mexico. --ado

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Re: Fault in tztab on HP-UX
by Monty Solomon Feb. 10, 1996

Feb. 10, 1996

FYI Begin forwarded message: Newsgroups: comp.sys.hp.hpux From: hmc(a)cee.hw.ac.uk (Hugh Conner) Subject: Re: Fault in tztab on HP-UX Message-Id: <DGwHBL.DI9(a)cee.hw.ac.uk> Sender: news(a)cee.hw.ac.uk (News Administrator) Organization: Dept of Computing & Electrical Engineering, Heriot-Watt University, Scotland References: <308A28E6.186D(a)ug.eds.com> Date: Mon, 23 Oct 1995 11:59:45 GMT In article <308A28E6.186D(a)ug.eds.com>, Daniel Dignam <daniel(a)ug.eds.com> writes: > There's a fault in the tztab entry for GMT0BST in 9.05, the clocks went > back today (the 22nd), but date under HP-UX is still stuck at BST :-(. > The relevant entry from tztab is as follows > > > # Greenwich Mean Time, British Summer Time > GMT0BST > 0 3 25-31 3 1983-1984 0 BST-1 > 0 3 23-29 3 1985-1990 0 BST-1 > 0 3 25-31 3 1991-2038 0 BST-1 > 0 1 25-31 10 1983-1985 0 GMT0 > 0 1 23-29 10 1986-2038 0 GMT0 > > As I understand this table it should read > > 0 1 22-29 10 1986-2038 0 GMT0 > > Anways, I guess the technology will sort itself out tomorrow, I wonder > how much breaks because of this ? The problem is that they decided to change the clocks back a week earlier than normal this year, thus screwing up all Unix systems time tables, not just HPs. I believe that next year it will be changed again so that Britain changes over at the same time as the rest of Europe, so you'll have to edit the tztab all over again. -- Hugh M. Conner hmc(a)cee.hw.ac.uk "Wot? No signature!"

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tztab changes for HPUX
by Monty Solomon Feb. 10, 1996

Feb. 10, 1996

FYI Begin forwarded message: From: ajm(a)hpwin064.uksr.hp.com (Andy Monks) Newsgroups: comp.sys.hp.hpux Subject: tztab changes for HPUX Date: 23 Oct 1995 11:03:18 GMT Organization: Hewlett-Packard Message-Id: <46fspm$bhk(a)hpwin055.uksr.hp.com> -----BEGIN PGP SIGNED MESSAGE----- Dear Customer, Recent legislation has redefined the date at which we change between British Summer Time and Greenwich Mean Time. In 1995 we will return to GMT on 22nd October at 02:00 BST. The timezone adjustment table supplied with HP-UX does not take these legislative changes into account, and therefore modifications must be made if the time change is to take place correctly. The file to be modified is /usr/lib/tztab; it can be modified using vi. The section for British time is headed with the line "# Greenwich Mean Time, British Summer Time", and the table beneath it must be modified to resemble the table below: # Greenwich Mean Time, British Summer Time GMT0BST 0 3 25-31 3 1983-1984 0 BST-1 0 3 23-29 3 1985-1990 0 BST-1 0 3 25-31 3 1991-1994 0 BST-1 0 2 25-31 3 1995-2038 0 BST-1 0 1 25-31 10 1983-1985 0 GMT0 0 1 23-29 10 1986-1994 0 GMT0 0 1 21-27 10 1995 0 GMT0 0 1 25-31 10 1996-2038 0 GMT0 Note: The character 0 is the number zero in all cases include the GMT0BST line. IF THESE MODIFICATIONS ARE NOT MADE, YOUR SYSTEM WILL NOT CHANGE TO GMT ON 22ND OCTOBER THIS YEAR. It is also important to restart the cron daemon. If you need any further information, please contact the Hewlett-Packard Response Centre on 01344-366366. Yours faithfully, The Response Centre -----BEGIN PGP SIGNATURE----- Version: 2.6.2i iQCVAwUBMIt1+zjIE3zxzhaxAQHcoQQA1JEkjfFdwIDdKnCO1yAX1y9b/dJtU6aB uUAeBbZuONFAWJLlbkVO0FwU2RvXAGfbiApTQapxwlL2RBkU4u23Yynu+D6c4/Zy sK3LcHy2acBY3CTV1tr9py+Ya3v5ZdkiYnM726JGJhDJ3QefKMKkpQRnev3zlkUz QRK8WlbPbWU= =OJEn -----END PGP SIGNATURE-----

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proposed patch for Mexico
by Paul Eggert Feb. 10, 1996

Feb. 10, 1996

I asked on the net about Mexico's DST rule change this year; the most authoritative-sounding response I got was from Kevin Pitts, so I've included his version in the patch proposed below. Further corrections may be needed, since there seems to be some confusion about the changes; e.g. in http://mexico-travel.com/mex_eng.html, Mexico's Ministry of Tourism claims that Mexico switched to US style DST rules way back in spring 1994. =================================================================== RCS file: RCS/northamerica,v retrieving revision 1995.13 retrieving revision 1995.13.1.1 diff -c -r1995.13 -r1995.13.1.1 *** northamerica 1995/12/21 17:18:31 1995.13 --- northamerica 1996/02/10 04:40:26 1995.13.1.1 *************** *** 852,857 **** --- 852,866 ---- # Shanks also says there are four zones, but disagrees about the fourth. # Instead of GMT-6 with DST, he says there's GMT-8 without DST. + # From Paul Eggert (1996-02-07): + # Today in news:4f90v4$g6g@news.internet.com.mx, Kevin Pitts + # <bravo2(a)internet.com.mx> wrote that Mexico will use Horario de Verano (DST) + # starting this year with the same rules as the US, and gave FIDE as a source. + # (FIDE is a private organization that promotes efficient electrical use.) + # On 1996-02-02 Mario Camou wrote that the transition times are Apr Sun>=1 + # 0:00 and Nov 1 0:00 but also wrote ``The DST-out date looks a bit fishy''. + # Go with Pitts after 1996, and with Shanks before that. + # From Shanks (1991): # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S Rule Mexico 1922 only - Jan 1 0:00 0 S *************** *** 863,868 **** --- 872,880 ---- Rule Mexico 1944 only - May 1 0:00 0 S Rule Mexico 1950 only - Feb 12 0:00 1:00 D Rule Mexico 1950 only - Jul 30 0:00 0 S + Rule Mexico 1996 max - Apr Sun>=1 2:00 1:00 D + Rule Mexico 1996 max - Oct lastSun 2:00 0 S + # Rule BajaN 1950 1966 - Apr lastSun 2:00 1:00 D Rule BajaN 1950 1961 - Sep lastSun 2:00 0 S Rule BajaN 1961 1966 - Oct lastSun 2:00 0 S *************** *** 883,902 **** -6:00 - CST 1942 Apr -7:00 - MST 1949 Jan 14 -8:00 - PST 1970 ! -7:00 - MST Zone America/Tijuana -7:48:04 - LMT 1922 Jan 1 0:11:56 -8:00 - PST 1927 Jun 10 23:00 -7:00 - MST 1930 Nov 16 -8:00 - PST 1942 Apr -7:00 - MST 1949 Jan 14 -8:00 BajaN P%sT 1967 Apr lastSun 2:00 ! -8:00 US P%sT Zone America/Ensenada -7:46:28 - LMT 1922 Jan 1 0:13:32 -8:00 - PST 1927 Jun 10 23:00 -7:00 - MST 1930 Nov 16 -8:00 - PST 1942 Apr -7:00 - MST 1949 Jan 14 ! -8:00 - PST # # Revillagigedo Is # no information --- 895,916 ---- -6:00 - CST 1942 Apr -7:00 - MST 1949 Jan 14 -8:00 - PST 1970 ! -7:00 Mexico M%sT Zone America/Tijuana -7:48:04 - LMT 1922 Jan 1 0:11:56 -8:00 - PST 1927 Jun 10 23:00 -7:00 - MST 1930 Nov 16 -8:00 - PST 1942 Apr -7:00 - MST 1949 Jan 14 -8:00 BajaN P%sT 1967 Apr lastSun 2:00 ! -8:00 US P%sT 1996 ! -8:00 Mexico P%sT Zone America/Ensenada -7:46:28 - LMT 1922 Jan 1 0:13:32 -8:00 - PST 1927 Jun 10 23:00 -7:00 - MST 1930 Nov 16 -8:00 - PST 1942 Apr -7:00 - MST 1949 Jan 14 ! -8:00 - PST 1996 ! -8:00 Mexico P%sT # # Revillagigedo Is # no information

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DST in Mexico
by Alan.Perry＠Eng.Sun.COM Feb. 3, 1996

Feb. 3, 1996

This is what I got from our Mexico subsidiary. ------------- Begin Forwarded Message ------------- Date: Fri, 02 Feb 1996 19:38:38 -0600 From: Mario Camou - Sun Mexico Hi Alan, I finally got the info: DST-in date: 1st Sunday in April @ midnight (0:00) (bump clock 1 hour forward) DST-out date: October 31st @ midnight (24:00) (bump clock 1 hour back) TZ's affected: All of Mexico (Mexico/General, Mexico/BajaNorte and Mexico/BajaSur) The DST-out date looks a bit fishy, I'd think it more logical to put it @ the last sunday in October or something like that. However, this is the info I was able to get, and since I'm travelling to Los Angeles next week I thought it better to forward it to you now. -------------- End Forwarded Message --------------

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Is Mexico starting DST back up?
by Alan.Perry＠Eng.Sun.COM Jan. 31, 1996

Jan. 31, 1996

I just got a query from our Mexico subsidiary stating that Mexico is resuming DST in April (after many years of not doing DST). This is not reflected in the current tzdata from elsie. Does anyone have any details about this? alan

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Bangalore not in the same time zone as Calcutta?
by guy＠netapp.com Jan. 30, 1996

Jan. 30, 1996

This is a message that showed up in "info.sun-managers"; the only time zone I could find for India in the "tzdata96b" file was # India # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Asia/Calcutta 5:53:28 - LMT 1880 5:53 - CMT 1941 Oct # Calcutta Mean Time 6:30 - BMT 1942 May 15 5:30 - IST 1942 Sep 5:30 1:00 IST 1945 Oct 15 5:30 - IST which is 5 1/2 hours from GMT, not 5 hours from GMT.... From: jerome(a)india.ti.com (Jerome Alphonse) Newsgroups: info.sun-managers Subject: date problems between Solaris and SunOS Date: 27 Jan 1996 20:06:01 -0600 Organization: UTexas Mail-to-News Gateway Message-ID: <199601270204.HAA02126(a)supernova.india.ti.com> Hello Gurus Our timezone is GMT+5. We have setup our machines in this timezone So in SunOS machines , if I give date command ,the output is Sat Jan 27 06:45:57 GMT+0500 1996 Which seems to be okay. In Solaris machines, if I give date command, the output is (though we have set it up as GMT+5,during installation) Sat Jan 27 06:45:01 GMT 1996 Becoz' of which we are not able to run certain Solaris applications which look into SUNOS or HP-UX machines for licensing as license gives error saying that time gap is more than it could handle (probably those wretched 5 hours). Becoz of this time stamp of the files created across NFS( between SUNOS and Solaris), is also crazy In Solaris machines -rw-rw-r-- 1 aravind 0 Jan 26 20:47 123 -rw-rw-r-- 1 aravind 0 Jan 26 20:47 234 In Solaris machines ,same files(across NFS) -rw-rw-r-- 1 aravind 0 Jan 27 06:47 123 -rw-rw-r-- 1 aravind 0 Jan 27 06:47 234 And also due to this time zone problem , I suspect there are some NFS mount problems which I posted in this forum a day or two before. Regards Jerome \\|// \\|// @@@@ ($$) (@@) (!!) ----o00--()--00o------o00--()--o00--------o00-()-00o------ Jerome Alphonse Email: jerome(a)india.ti.com Systems Engineer Phone: 011-91-80-2264235/9 Texas Instruments Fax : 011-91-80-2267024 Bangalore 560052 India URL : http://www.india.ti.com/~jerome/ ===========================================================

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tzdata96b.tar.gz
by ado Jan. 27, 1996

Jan. 27, 1996

The file tzdata96b.tar.gz is now available from elsie.nci.nih.gov (165.112.73.1): -rw-r--r-- 1 ado 73021 Jan 27 15:44 tzdata96b.tar.gz This includes the Kiribati change. --ado

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