I'm forwarding this message from Raymond Hughes, who is not on the time zone mailing list. Those of you who are on the list, please direct replies appropriately. (Right now http://www.mcil.gov.ws is unavailable--at least from the system I'm using--but Googling "03/04/11 adjust clocks" and using the "Cache" link provides the content). --ado -----Original Message----- From: Raymond Hughes [mailto:raymond@hughes.ws] Sent: Thursday, October 07, 2010 9:36 To: tz@lecserver.nci.nih.gov Subject: Re: Samoa the start of DST here is Samoa was OK from what I've seen, but looking at my zdump I see the ending does not have the correct times. Sun Sep 26 10:59:59 2010 UTC = Sat Sep 25 23:59:59 2010 WST isdst=0 Sun Sep 26 11:00:00 2010 UTC = Sun Sep 26 01:00:00 2010 WSDT isdst=1 Sun Apr 3 09:59:59 2011 UTC = Sat Apr 2 23:59:59 2011 WSDT isdst=1 Sun Apr 3 10:00:00 2011 UTC = Sat Apr 2 23:00:00 2011 WST isdst=0 Please see www.mcil.gov.ws, the Ministry of Commerce, Industry and Labour (sideframe) "Last Sunday September 2010 (26/09/10) - adjust clocks forward from 12:00 midnight to 01:00am and First Sunday April 2011 (03/04/11) - adjust clocks backwards from 1:00am to 12:00am" PS. Thanks Maintainers Regards Ray
Hello! Currently the rules for Palestine are: Rule Palestine 2010 max - Mar lastSat 0:01 1:00 S Rule Palestine 2009 max - Sep Fri>=1 2:00 0 - Rule Palestine 2010 only - Aug 11 0:00 0 - The first line is fine, this is the start-date and says it's in effect from 2010 going forward. The last two lines appear to overlap. The second line says the end-date is the first Friday in Sept starting in 2009 going forward (including 2010). The last line says in 2010 the end-date is Aug 11. I do see that Alexander Krivenyshev (2010-07-20)pointed out the "Clocks to go back during Ramadan--and then forward again" I believe this Aug 11 end-date is a one-time exception. So, does the following make sense, to avoid the overlapping rules for the end date? Rule Palestine 2010 max - Mar lastSat 0:01 1:00 S Rule Palestine 2009 only - Sep Fri>=1 2:00 0 - Rule Palestine 2010 only - Aug 11 0:00 0 - Rule Palestine 2011 max - Sep Fri>=1 2:00 0 - Would this not be more acceptable? I have yet to encounter any overlapping of rules previous to this one. Am I missing something? Thank you for your time! Christina Schneider
The current rules may capture the Palestinian reality--a regular DST end date was established in 2009 (applying from "2009" to "max") with a one-time exception this year ("2010 only"). (Note that the time zone compiler notices that nothing changes on the first Friday of September, 2010 and does not produce any "extra" output.) --ado -----Original Message----- From: Christina Lawrence [mailto:CLawrence@stopwatchmaps.com] Sent: Tuesday, October 12, 2010 1:56 To: tz@elsie.nci.nih.gov; 'tz@elsie.nci.nih.gov' Subject: overlapping of rules? - Palestine Hello! Currently the rules for Palestine are: Rule Palestine 2010 max - Mar lastSat 0:01 1:00 S Rule Palestine 2009 max - Sep Fri>=1 2:00 0 - Rule Palestine 2010 only - Aug 11 0:00 0 - The first line is fine, this is the start-date and says it's in effect from 2010 going forward. The last two lines appear to overlap. The second line says the end-date is the first Friday in Sept starting in 2009 going forward (including 2010). The last line says in 2010 the end-date is Aug 11. I do see that Alexander Krivenyshev (2010-07-20)pointed out the "Clocks to go back during Ramadan--and then forward again" I believe this Aug 11 end-date is a one-time exception. So, does the following make sense, to avoid the overlapping rules for the end date? Rule Palestine 2010 max - Mar lastSat 0:01 1:00 S Rule Palestine 2009 only - Sep Fri>=1 2:00 0 - Rule Palestine 2010 only - Aug 11 0:00 0 - Rule Palestine 2011 max - Sep Fri>=1 2:00 0 - Would this not be more acceptable? I have yet to encounter any overlapping of rules previous to this one. Am I missing something? Thank you for your time! Christina Schneider
On 2010-10-13 18:29, Arthur David Olson wrote on superfluous time zone rules:
(Note that the time zone compiler notices that nothing changes on the first Friday of September, 2010 and does not produce any "extra" output.)
Yes, obviously a switch to winter time directly after another switch to winter time should not hurt. But such "overlapping" switches may confuse a human reader, and in some (imaginary) cases, even the compiler. Consider a rule like # Rule NAME FROM TO TYPE IN ON AT SAVE Rule Palestine 2009 max - Mar lastFri 0:00 1 It says that summer time is used from its value [a] 2009-03-27 + 01 h onwards if winter time has applied before that instant. If summer time had already applied before that instant, then the rule would say that summer time is used from its value [b] 2009-03-27 + 00 h onwards which is, in fact, one hour earlier. Together with the (fictitious) "overlapping" rule # Rule NAME FROM TO TYPE IN ON AT SAVE Rule Palestine 2009 only - Mar 26 23:30 1 which specifies summer time from [c] 2009-03-27 + 00:30 h onwards, the interpretation becomes doubtful: if the second rule [c] is honored, then [a] cannot really apply because local time never took the value 2009-03-27 + 00 h; but [b] implies that [c] cannot apply because local time could never have taken the value 2009-03-26 + 23:30 h. I am not saying that this is a real problem -- I am just proposing to avoid any "overlapping" (useless and potentially confusing) rules. Michael Deckers.
participants (3)
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Christina Lawrence -
Michael Deckers -
Olson, Arthur David (NIH/NCI) [E]