- tz - lists.iana.org

Australian Timezone issues.
by Chris Bitmead May 9, 1999

May 9, 1999

I understand this is the appropriate email address for addressing issues with the standard UNIX timezone files. Has any thought been given to having the Australian EST timezone renamed to AEST? The conflicting name with the American EST has caused too much grief for too long. AEST is the proper abbreviation anyway in an international context and is reported on international radio broadcasts that refer to Australian timezones. The current practice of using plain EST simply breaks everything. For example, when a database dumps a time 'Sun May 9 11:07:06 EST 1999 in Australia, and then the database reads the time back in, it assumes that EST is New York time and everything gets screwed up. Another example, typing date in Australia's EST zone gives Sun May 9 11:07:06 EST 1999 But typing TZ=EST date Sat May 8 20:07:06 EST 1999 Inconsistent or what? As far as I know it is only Australian zones which suffer from this stupidity. It basicly renders timezones partly useless in Australia, because the timezone abbreviation of EST is ambiguous, and whenever interpreted, it's always done wrongly as NY time. This means that a lot of UNIX software simply doesn't work properly in Australia. Frankly I count the standard UNIX date program amoungst the many because the time it reports as EST is different to the date it reports when TZ=EST. What would have to be done to get this changed in the zoneinfo files? -- Chris Bitmead http://www.bigfoot.com/~chris.bitmead mailto:chris.bitmead@bigfoot.com

1 0

Re: FW: POSIX-TZ without rules
by Guido Flohr May 5, 1999

May 5, 1999

On Thu, Apr 29, 1999 at 04:39:29PM -0700, Paul Eggert wrote: > From: Guido Flohr [SMTP:gufl0000@stud.uni-sb.de] > Sent: Monday, April 26, 1999 9:46 PM > > for testing purposes I set the envariable TZ to "CET-1CEST-2", > i. e. a valid POSIX-style string but without explicit rules. > I also uninstalled the database for that test. > > Under these circumstances tzparse() in localtime.c will return an error > because it fails to open a default rules file. From what I remember I > would say that POSIX demands that the US rules should be applied instead. > > POSIX.1 is not US-centric here; it says that the behavior in this case > is implementation-defined. The rationale (POSIX 1003.1-1996 section > B.8.1.1 page 493 lines 5609-5612) says ``An implementation may provide > those rules [i.e. the DST rules not explicitly specified by the user] OK, I'll never use the word POSIX again. ;-) My information is only second hand. > Anyway, "CET-1CEST-2" is perfectly POSIX-compliant and the library should > not return an error then. > > Yes. My reading of POSIX.1 is that the implementation is allowed to > guess the DST rules, but it's not allowed to fail. I agree. A popular German Unix guide recommends "CET-1CEST-2" as the default TZ setting for Germany, German HP-UX distributions use it to (well, with "MET" instead of "CET"). > The GNU libc handles this case by assuming an implicit rule of > "M4.1.0,M10.5.0" (commented as "US Federal Law"). My solution is somewhat > different: I generated a header "new_york.h" > > Both solutions have problems. The first mishandles old dates; the > second assumes the New York City DST rules, whereas it'd be better to > assume only the US rules. Implementing the plain US rules (back to > 1918) would be better; can you do this? Do you mean writing a rules file for that case (which could be compiled and hardcoded into the library)? Actually I even have problems with that solution. I think we had better leave DST alone if no rules are available. Guessing rules always means to do exactly the wrong thing for half of the world, assuming rules that are suitable for the northern hemisphere means to discriminate the southern hemisphere. Correct me if I'm wrong, but isn't it possible to explicitely mark that question as undecidable by setting tm->tm_isdst resp. the variable daylight to -1? Collecting back data which will most probably provide wrong results looks a little ridiculous to me. What should we do when time_t grows 64 bits big? Guess if Alexander arrived one hour early at Issos because the Greek had DST and the Persians hadn't? > > In zic.c, the analysis of the return value of > system("yearistype ...") assumes a certain structure of that return value. > > That's clearly a portability bug; here's a patch. Fine. > +#if HAVE_SYS_WAIT_H - 0 > +#include <sys/wait.h> /* for WIFEXITED and WEXITSTATUS */ > +#endif /* HAVE_SYS_WAIT_H - 0 */ > + > +#ifndef WIFEXITED > +#define WIFEXITED(status) (((status) & 0xff) == 0) > +#endif /* !defined WIFEXITED */ > +#ifndef WEXITSTATUS > +#define WEXITSTATUS(status) (((status) >> 8) & 0xff) > +#endif /* !defined WEXITSTATUS */ Will that work on BSD systems with a union wait? system() returns int, so what does BSD recommend to get the status bits? Sorry, I don't know, I just want to point out a possible problem. Ciao Guido -- http://stud.uni-sb.de/~gufl0000 mailto:gufl0000@stud.uni-sb.de

1 0

FW: accessing DST rules at runtime
by Olson, Arthur David (NCI) April 20, 1999

April 20, 1999

-----Original Message----- From: Dave Hackenyos [SMTP:hackenyo@roguewave.com] Sent: Friday, April 16, 1999 8:12 PM To: ado(a)elsie.nci.nih.gov Subject: accessing DST rules at runtime Hello, I have been working on an implementation problem about which you may have some insight. I hope you don't mind a question or two. I am attempting to discover a way to query any (most) Operating Systems about what it may think the daylight rule is for the Timezone in which it thinks it is located. I wish to do this at runtime. I am aware that a call to tzset() will set a host of information, but only a few are available to the programmer (tzname, daylight, etc). I cannot find a way to get at the exact DST rule information even though the system is well aware of it during every call of localtime(). Your tar files at elsie.nci.nih.gov are full of info about the subject and several, if not all platforms of interest to me use it. Your localtime() function seems to know how to parse these binary zoneinfo files, but once again, I am unable to discern how to access the DST rule info for my own use. My question: Could you shed some light on how (given knowledge of the path to a particular OS's zoneinfo location) one could gleen the DST rule at runtime? I would be forever in your debt. Thanks for any help you could send my way, Dave Hackenyos hackenyo(a)roguewave.com (541)754-2976

2 1

Jordan do not have DST this year
by Steffen Thorsen April 7, 1999

April 7, 1999

It also seems that they are not going to use it the next years either. "We do not need it" was the answer I got from the Jordan National Information Centre (http://www.nic.gov.jo) Best regards, Steffen

1 0

RE: new UK proposal
by Lee Geoff April 6, 1999

April 6, 1999

This might be good in the UK and very good in Germany but what about our southern EC neighbours? The Spanish would lose an hour of sleep from their siesta which sounds like a bad idea when it will be applied every day. Has anyone any bright ideas for the former Yugoslavia where the clocks seem to have been put back 50 years? Geoff. > -----Original Message----- > From: Martin Burnicki [SMTP:martin.burnicki@meinberg.de] > Sent: Tuesday, April 06, 1999 2:00 PM > To: tz(a)elsie.nci.nih.gov > Subject: Re: new UK proposal > > ***** This message originated from outside the AA ***** > > Peter Ilieve wrote: > > > > The following letter appeared in the Independent (a UK `quality' > > broadsheet paper) on 31 March, so was presumably not an April Fool > > (although I have my doubts :-): > > --- > > Time for reform > > > > Sir: I cannot be the only person who felt disoriented on Sunday > > morning after losing an hour's sleep, but who was grateful for the > > prospect of lighter evenings. Nevertheless, I feel that permanent > > British Summer Time would not be appropriate because of excessively > > long dark mornings in Scotland, and the loss of October's extra > > hour in bed would be hard to bear. > > May I therefor suggest that the country adopts Greenwich Mean Time > > in the mornings, and BST in the afternoons? The clocks could go > > forward after lunch and back around 2am. This would reduce the > > working week (currently far too long for most people) and give > > everyone an extra hour in bed every night. Evenings would be lighter, > > and mornings not too dark in winter. Why has nobody thought of this > > > before? > > > > John Parker > > London N3 > > --- > > > > Peter Ilieve peter(a)aldie.co.uk > > I think this is a VERY good idea. But remember we're the European > Community. That rule to determine beginning/end of daylight saving > should be used all over Europe, so we would also benefit from it in > Germany ;-) > > -- > > M. Burnicki > > Meinberg Funkuhren > Bad Pyrmont > Germany

1 0

new UK proposal
by peter＠aldie.co.uk April 6, 1999

April 6, 1999

The following letter appeared in the Independent (a UK `quality' broadsheet paper) on 31 March, so was presumably not an April Fool (although I have my doubts :-): --- Time for reform Sir: I cannot be the only person who felt disoriented on Sunday morning after losing an hour's sleep, but who was grateful for the prospect of lighter evenings. Nevertheless, I feel that permanent British Summer Time would not be appropriate because of excessively long dark mornings in Scotland, and the loss of October's extra hour in bed would be hard to bear. May I therefor suggest that the country adopts Greenwich Mean Time in the mornings, and BST in the afternoons? The clocks could go forward after lunch and back around 2am. This would reduce the working week (currently far too long for most people) and give everyone an extra hour in bed every night. Evenings would be lighter, and mornings not too dark in winter. Why has nobody thought of this before? John Parker London N3 --- Peter Ilieve peter(a)aldie.co.uk

3 2

FW: Timezone data
by Olson, Arthur David (NCI) April 6, 1999

April 6, 1999

Be sure replies are directed to Len Landau, who's not on the time zone mailing list. --ado -----Original Message----- From: Les Landau [SMTP:Les.Landau@digital.com] Sent: Monday, April 05, 1999 7:47 PM To: tz(a)elsie.nci.nih.gov Subject: Timezone data Hi, I got this e-mail address from www.timezone.com - I hope its OK to ask your advice. I'm trying to write a Visual Basic application to convert times between zones, and would like to get a database of timezone info in a form that I can read. Are you aware of a database that could be read by a windows application? Is there any documentation of its structure? Any help is most appreciated. Cheers, Les ---------------------------------------------------------------------------- ------------ Les Landau LanNet Services E-mail: LandauL(a)ozemail.com.au 8 Solander Place Phone: 0419 825242 Yarralumla Fax: 02 6282 8433 ACT 2600 Australia

1 0

Timezone data
by Les Landau April 5, 1999

April 5, 1999

Hi, I got this e-mail address from www.timezone.com - I hope its OK to ask your advice. I'm trying to write a Visual Basic application to convert times between zones, and would like to get a database of timezone info in a form that I can read. Are you aware of a database that could be read by a windows application? Is there any documentation of its structure? Any help is most appreciated. Cheers, Les ---------------------------------------------------------------------------- ------------ Les Landau LanNet Services E-mail: LandauL(a)ozemail.com.au 8 Solander Place Phone: 0419 825242 Yarralumla Fax: 02 6282 8433 ACT 2600 Australia

1 0

New RFC about time
by Antoine Leca April 2, 1999

April 2, 1999

A new RFC about time have been issued recently. from rfc-index 2550 Y10K and Beyond. S. Glassman, M. Manasse, J. Mogul. April-01-1999. (Format: TXT=28011 bytes) (Status: INFORMATIONAL) It is available from your favorite RFC repository. Worth consulting it. Antoine

1 0

storing timestamp data
by Lee Geoff April 1, 1999

April 1, 1999

Maiden email from a new subscriber. My interest is less in the intricacies of a complete world view of time zone settings and more in best practice for the storage of timestamp data in computer systems. I'm interested in storing date/time data in Ingres databases which are running on Unix servers. We are recording timed events on Unix servers as well as Windows 3.1 and NT PCs. I have had problems with the apparent miss-handling of data when viewed before or after a DST transition. Can anyone point me at words of wisdom or good advice? Geoff Lee

3 2