Re: [SLUG] Timezone and Daylight Savings Time
Jesus M. Salvo Jr. wrote: 1) Why is it EST ? Shouldn't it be EDT or AEDT ? tzdata uses the offical abbreviation for the timezone. There is no choice, the data is going to appear on legal documents under some applications. The offical abbreviation (or the abbreviation of the offical time zone name) is also a practical choice: it avoids some liabilities for the maintainers of the tzdata file. Some legislation is stupid -- for example it will define a X Standard Time and a X Summer Time. Presumably the legislators never thought that people might want to use an abbreviation, and there are usually no clauses disambiguating the abbreviations. No Australian state legislation defines a AXST or AXDT, that's just a common abbreviation. In Australia if you want to alter the abbreviation used by tzdata you need to alter the law. You can do this simply by asking your state to pass a regulation (the abbreviation for summer time shall be XDT). Most government officials won't be up for this, they are always afraid of knock-on consequences from this sort of action. Your best best is to wait for the regular review of legislation to reach the daylight savings laws and to send in a submission saying what a pain having XST/XST is. Daylight savings laws attract all sorts of nuts, so you might want to ask AUUG, ACS, AIIA to write supporting letters. An alternative would be for CSIRO to make a regulation, as they have the delegation of the Commonwealth's time-keeping powers (all this state nonsense about differing daylight savings can be easily over-ridden by the Commonwealth's Weights and Measures Constitutional power). But having a Commonwealth regulation modify a state law is usually regarded as a poor idea (since then the state law and commonwealth regulation need to be maintained in lock-step). Hope this helps explain the mess, glen -- Glen Turner Tel: (08) 8303 3936 or +61 8 8303 3936 Australia's Academic Research Network www.aarnet.edu.au -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
[SLUG] Timezone and Daylight Savings Time
Since this is the Sydney Linux Users Group ... I did not actually notice this before, but here it goes: When I run the 'date' command while we are in daylight savings time, it says: Tue Feb 1 13:35:07 EST 2005 1) Why is it EST ? Shouldn't it be EDT or AEDT ? http://www.timeanddate.com/library/abbreviations/timezones/au/edt.html I have checked the following already: 1a) TZ variable: set | grep TZ TZ=Australia/Sydney 1b) /etc/localtime: $) cksum /etc/localtime 1227095042 785 /etc/localtime $) cksum /usr/share/zoneinfo/Australia/Sydney 1227095042 785 /usr/share/zoneinfo/Australia/Sydney 1c) dump of the timezone file: $) /usr/sbin/zdump -v /usr/share/zoneinfo/Australia/Sydney snip /usr/share/zoneinfo/Australia/Sydney Sat Mar 27 15:59:59 2004 UTC = Sun Mar 28 02:59:59 2004 EST isdst=1 gmtoff=39600 /usr/share/zoneinfo/Australia/Sydney Sat Mar 27 16:00:00 2004 UTC = Sun Mar 28 02:00:00 2004 EST isdst=0 gmtoff=36000 /usr/share/zoneinfo/Australia/Sydney Sat Oct 30 15:59:59 2004 UTC = Sun Oct 31 01:59:59 2004 EST isdst=0 gmtoff=36000 /usr/share/zoneinfo/Australia/Sydney Sat Oct 30 16:00:00 2004 UTC = Sun Oct 31 03:00:00 2004 EST isdst=1 gmtoff=39600 /usr/share/zoneinfo/Australia/Sydney Sat Mar 26 15:59:59 2005 UTC = Sun Mar 27 02:59:59 2005 EST isdst=1 gmtoff=39600 snip Okay, the above file says EST with isdst=1, but again, shouldn't that be EDT instead ? 2) Anyone know how to change the output of date so that it shows the GMT offset instead ? -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Timezone and Daylight Savings Time
On Tue, Feb 01, 2005 at 01:43:11PM +1100, Jesus M. Salvo Jr. wrote: When I run the 'date' command while we are in daylight savings time, it says: Tue Feb 1 13:35:07 EST 2005 1) Why is it EST ? Shouldn't it be EDT or AEDT ? S for Summer. We don't do Daylight Time here. There are no legal or universal abbreviations for timezones in Australia. I've also seen EASST and EADT. In some places, I think it's also called L (or K in Queensland, right now...). http://www.timeanddate.com/library/abbreviations/timezones/au/edt.html And someone in Norway knows something that Australian governments and people don't? I have checked the following already: 1a) TZ variable: set | grep TZ TZ=Australia/Sydney 1b) /etc/localtime: $) cksum /etc/localtime 1227095042 785 /etc/localtime $) cksum /usr/share/zoneinfo/Australia/Sydney 1227095042 785 /usr/share/zoneinfo/Australia/Sydney Looks good. 1c) dump of the timezone file: $) /usr/sbin/zdump -v /usr/share/zoneinfo/Australia/Sydney snip /usr/share/zoneinfo/Australia/Sydney Sat Mar 27 15:59:59 2004 UTC = Sun Mar 28 02:59:59 2004 EST isdst=1 gmtoff=39600 /usr/share/zoneinfo/Australia/Sydney Sat Mar 27 16:00:00 2004 UTC = Sun Mar 28 02:00:00 2004 EST isdst=0 gmtoff=36000 /usr/share/zoneinfo/Australia/Sydney Sat Oct 30 15:59:59 2004 UTC = Sun Oct 31 01:59:59 2004 EST isdst=0 gmtoff=36000 /usr/share/zoneinfo/Australia/Sydney Sat Oct 30 16:00:00 2004 UTC = Sun Oct 31 03:00:00 2004 EST isdst=1 gmtoff=39600 /usr/share/zoneinfo/Australia/Sydney Sat Mar 26 15:59:59 2005 UTC = Sun Mar 27 02:59:59 2005 EST isdst=1 gmtoff=39600 snip Looks good. Okay, the above file says EST with isdst=1, but again, shouldn't that be EDT instead ? No. EDT is for New York and places nearby. 2) Anyone know how to change the output of date so that it shows the GMT offset instead ? Check the manual pages date(1) or strftime(3) if you have them. Depends on your OS. -- Christopher Vance -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Timezone and Daylight Savings Time
Christopher JS Vance wrote: On Tue, Feb 01, 2005 at 01:43:11PM +1100, Jesus M. Salvo Jr. wrote: When I run the 'date' command while we are in daylight savings time, it says: Tue Feb 1 13:35:07 EST 2005 1) Why is it EST ? Shouldn't it be EDT or AEDT ? S for Summer. We don't do Daylight Time here. Huh ? What do you mean we don't do daylight time here in NSW ? http://www.lawlink.nsw.gov.au/crd.nsf/pages/time2 There are no legal or universal abbreviations for timezones in Australia. I've also seen EASST and EADT. In some places, I think it's also called L (or K in Queensland, right now...). http://www.timeanddate.com/library/abbreviations/timezones/au/edt.html And someone in Norway knows something that Australian governments and people don't? 2) Anyone know how to change the output of date so that it shows the GMT offset instead ? Check the manual pages date(1) or strftime(3) if you have them. Depends on your OS. I know that you can format the output of the date command. What I was after was having the _default_ ( that is, no options ) output of date to display GMT offset instead of EST. -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Timezone and Daylight Savings Time
Quoting from Lawlink : Standard time in New South Wales (known as Eastern Standard Time)... Daylight saving begins at 2 a.m. Eastern Standard Time on the last Sunday in October... Therefore, at 2 a.m. standard time on the last Sunday in October clocks are put forward one hour- the time then becomes 3 a.m. summer time.. Maybe we should call it New South Wales Summer Daylight Saving Time or NSWSDST so we know we're not on Queensland Curtain Fading Time. Rod On Tue, 2005-02-01 at 14:36 +1100, Jesus M. Salvo Jr. wrote: Christopher JS Vance wrote: On Tue, Feb 01, 2005 at 01:43:11PM +1100, Jesus M. Salvo Jr. wrote: When I run the 'date' command while we are in daylight savings time, it says: Tue Feb 1 13:35:07 EST 2005 1) Why is it EST ? Shouldn't it be EDT or AEDT ? S for Summer. We don't do Daylight Time here. Huh ? What do you mean we don't do daylight time here in NSW ? http://www.lawlink.nsw.gov.au/crd.nsf/pages/time2 There are no legal or universal abbreviations for timezones in Australia. I've also seen EASST and EADT. In some places, I think it's also called L (or K in Queensland, right now...). http://www.timeanddate.com/library/abbreviations/timezones/au/edt.html And someone in Norway knows something that Australian governments and people don't? 2) Anyone know how to change the output of date so that it shows the GMT offset instead ? Check the manual pages date(1) or strftime(3) if you have them. Depends on your OS. I know that you can format the output of the date command. What I was after was having the _default_ ( that is, no options ) output of date to display GMT offset instead of EST. -- --- Brought to you by a penguin, a gnu and a camel -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Timezone and Daylight Savings Time
On Tue, Feb 01, 2005 at 02:36:23PM +1100, Jesus M. Salvo Jr. wrote: S for Summer. We don't do Daylight Time here. Huh ? What do you mean we don't do daylight time here in NSW ? http://www.lawlink.nsw.gov.au/crd.nsf/pages/time2 That page doesn't mention daylight time anywhere. It talks everywhere of daylight saving, and doesn't give a name to the timezone. Your proposed abbreviation for the timezone name didn't include an S for the saving part of daylight saving, either. I've heard the timezone most frequently called Summer time around here. I know that you can format the output of the date command. What I was after was having the _default_ ( that is, no options ) output of date to display GMT offset instead of EST. The Unix standard was three characters for a time zone name. POSIX has increased the maximum number allowed to at least six, but it took a while before more than three wouldn't break things. POSIX does say that the timezone name may not include digits, so you won't be changing the default on any systems but your own. Look for zic, zdump, etc. Or just recompile date. Or make a wrapper script. -- Christopher Vance -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Timezone and Daylight Savings Time
Christopher JS Vance wrote: On Tue, Feb 01, 2005 at 02:36:23PM +1100, Jesus M. Salvo Jr. wrote: S for Summer. We don't do Daylight Time here. Huh ? What do you mean we don't do daylight time here in NSW ? http://www.lawlink.nsw.gov.au/crd.nsf/pages/time2 That page doesn't mention daylight time anywhere. It talks everywhere of daylight saving, and doesn't give a name to the timezone. OK ... I finally see what your original statement meant. Your proposed abbreviation for the timezone name didn't include an S for the saving part of daylight saving, either. I've heard the timezone most frequently called Summer time around here. Understood ... but it just seems that it has been sort of accepted practice that there is a different abbrevation for standard vs. daylight savings time. For example, most sites use AEDT to describe Australian Easter Daylight Savings Time, from abc.gov.au, defense.gov.au, abc.net.au ... etc.. ), including the following link: http://www.ga.gov.au/nmd/geodesy/astro/sunrise.jsp Furthermore, here is a link: http://www.statoids.com/tau.html .. and it says, under Time zone names, that AEDT is the abbreviation -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Timezone and Daylight Savings Time
On Tue, Feb 01, 2005 at 03:58:29PM +1100, Jesus M. Salvo Jr. wrote: http://www.lawlink.nsw.gov.au/crd.nsf/pages/time2 That page doesn't mention daylight time anywhere. It talks everywhere of daylight saving, and doesn't give a name to the timezone. OK ... I finally see what your original statement meant. The previous page http://www.lawlink.nsw.gov.au/crd.nsf/pages/time1 actually calls it summer time, too, although never in capitals. That's probably as close to official as you'll get in NSW. Hence EST. :-( Understood ... but it just seems that it has been sort of accepted practice that there is a different abbrevation for standard vs. daylight savings time. It's a good idea from a computing viewpoint, but governments don't seem to have made an official Act or Regulation to specify any abbreviations. The words wise and government don't often appear in the same sentence, unless mixed with sarcasm. .. and it says, under Time zone names, that AEDT is the abbreviation I do agree that's probably the most common and sensible 4-letter abbreviation for it, but it's not the only one. I usually just say +1100 (and write dates like 2005-02-01) but AEDT also works for me when the conversion is explicitly about Australia. -- Christopher Vance -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Timezone and Daylight Savings Time
So back to the question ... should our linux computer shows EST when we are under daylight savings time ? It just does not feel / look right keeping the same timezone abbrevation for both standard and daylight savings time in NSW, regardless of whether or our government makes an official timezone abbrevations. -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Timezone and Daylight Savings Time
Jesus M. Salvo Jr. wrote: So back to the question ... should our linux computer shows EST when we are under daylight savings time ? It just does not feel / look right keeping the same timezone abbrevation for both standard and daylight savings time in NSW, regardless of whether or our government makes an official timezone abbrevations. Maybe useful or not, maybe it will even __break__ things, but I gave this a try on one of my test servers: [EMAIL PROTECTED] jsalvo]# export TZ=AEST-10AEDT,M10.5.0/2,M3.5.0/3 Now let's watch it change from standard time to daylight savings time abbreviation: [EMAIL PROTECTED] jsalvo]# date --set='2004-10-31 01:59:45' Sun Oct 31 01:59:45 AEST 2004 [EMAIL PROTECTED] jsalvo]# date Sun Oct 31 01:59:54 AEST 2004 [EMAIL PROTECTED] jsalvo]# date Sun Oct 31 01:59:58 AEST 2004 [EMAIL PROTECTED] jsalvo]# date Sun Oct 31 03:00:00 AEDT 2004 -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Timezone and Daylight Savings Time
Jesus M. Salvo Jr. wrote: Furthermore, here is a link: http://www.statoids.com/tau.html .. and it says, under Time zone names, that AEDT is the abbreviation Agh! .. Missed the part there in that link that says EST is actually used as an abbreviation for __both__ Eastern Standard Time __and__ Eastern Summer Time. Ugh! Why wasn't a different abbreviation used. -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
