I'm forwarding this message from Dafydd Rhys-Jones, who sent it before joining the time zone mailing list. --ado From: Dafydd Rhys-Jones [mailto:D.Rhys-Jones@F5.com] Sent: Wednesday, August 29, 2007 5:38 To: tz@lecserver.nci.nih.gov Subject: EU BST-->GMT issue Hello all, Are there any known bugs revolving around the EU timezone not reverting from BST back to GMT? [root@server2 ~]# rm -f /etc/localtime ; ln -s /usr/share/zoneinfo/Europe/London /etc/localtime [root@server2 ~]# date Wed Aug 29 21:42:31 BST 2007 [root@server2 ~]# date -s "Sun Oct 26 00:59:59 2008" Sun Oct 26 00:59:59 BST 2008 [root@server2 ~]# date Sun Oct 26 00:59:59 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:01 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:02 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:03 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:04 BST 2008 [root@server2 ~]# date -s "Sun Oct 26 01:00:01 2008" Sun Oct 26 01:00:01 GMT 2008 Dafydd Rhys-Jones | Software Test Engineer F5 Networks P 206.272.5555 F 206.272.5556 www.f5.com D 206.272.6280 M 206.335.1096
That looks correct to me. The reversion occurs at 0100 UTC (which is to say 2am BST or 1am GMT), so wallclock times from 1am until 2am are repeated at the fall-back. J Andrew Lipscomb, CPA*ABV, ASA Decosimo Corporate Finance 900 Tallan Building 2 Union Square Chattanooga, TN 37402 423.756.7100 Fax 423.266.6671 www.dcf.decosimo.com Are there any known bugs revolving around the EU timezone not reverting from BST back to GMT? [root@server2 ~]# rm -f /etc/localtime ; ln -s /usr/share/zoneinfo/Europe/London /etc/localtime [root@server2 ~]# date Wed Aug 29 21:42:31 BST 2007 [root@server2 ~]# date -s "Sun Oct 26 00:59:59 2008" Sun Oct 26 00:59:59 BST 2008 [root@server2 ~]# date Sun Oct 26 00:59:59 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:01 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:02 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:03 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:04 BST 2008 [root@server2 ~]# date -s "Sun Oct 26 01:00:01 2008" Sun Oct 26 01:00:01 GMT 2008 Dafydd Rhys-Jones | Software Test Engineer F5 Networks P 206.272.5555 F 206.272.5556 www.f5.com D 206.272.6280 M 206.335.1096
If I manually set the time to 1 second after the reversion, it will set it to GMT, however, if I set it before the reversion time, and let it roll over said reversion time, it remains BST. The first command below shows where I set it before rolling over reversion time, and the command at the end after all the date checks showing reversion did not occur is the command where I set it +1 second over reversion time, and it does set it to GMT. Dafydd Dafydd Rhys-Jones | Software Test Engineer F5 Networks P 206.272.5555 F 206.272.5556 www.f5.com D 206.272.6280 M 206.335.1096 -----Original Message----- From: Andy Lipscomb [mailto:AndyLipscomb@decosimo.com] Sent: Thursday, August 30, 2007 7:52 AM To: tz@lecserver.nci.nih.gov Subject: RE: EU BST-->GMT issue That looks correct to me. The reversion occurs at 0100 UTC (which is to say 2am BST or 1am GMT), so wallclock times from 1am until 2am are repeated at the fall-back. J Andrew Lipscomb, CPA*ABV, ASA Decosimo Corporate Finance 900 Tallan Building 2 Union Square Chattanooga, TN 37402 423.756.7100 Fax 423.266.6671 www.dcf.decosimo.com Are there any known bugs revolving around the EU timezone not reverting from BST back to GMT? [root@server2 ~]# rm -f /etc/localtime ; ln -s /usr/share/zoneinfo/Europe/London /etc/localtime [root@server2 ~]# date Wed Aug 29 21:42:31 BST 2007 [root@server2 ~]# date -s "Sun Oct 26 00:59:59 2008" Sun Oct 26 00:59:59 BST 2008 [root@server2 ~]# date Sun Oct 26 00:59:59 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:01 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:02 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:03 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:04 BST 2008 [root@server2 ~]# date -s "Sun Oct 26 01:00:01 2008" Sun Oct 26 01:00:01 GMT 2008 Dafydd Rhys-Jones | Software Test Engineer F5 Networks P 206.272.5555 F 206.272.5556 www.f5.com D 206.272.6280 M 206.335.1096
Whenever I've tested the "fall back", I have to let it sit for over an hour - so set it to 11:59, let it roll over midnight, get to 1 am and then flip back to 12am. The system knows it has to go through the 12am to 1am period twice - just setting it to roll over the first time, it doesn't seem to know to flip back. If the roll over is at 2am, adjust this method accordingly. -----Original Message----- From: Dafydd Rhys-Jones [mailto:D.Rhys-Jones@F5.com] Sent: Thursday, August 30, 2007 11:00 AM To: tz@lecserver.nci.nih.gov; tz@lecserver.nci.nih.gov Subject: RE: EU BST-->GMT issue If I manually set the time to 1 second after the reversion, it will set it to GMT, however, if I set it before the reversion time, and let it roll over said reversion time, it remains BST. The first command below shows where I set it before rolling over reversion time, and the command at the end after all the date checks showing reversion did not occur is the command where I set it +1 second over reversion time, and it does set it to GMT. Dafydd Dafydd Rhys-Jones | Software Test Engineer F5 Networks P 206.272.5555 F 206.272.5556 www.f5.com D 206.272.6280 M 206.335.1096 -----Original Message----- From: Andy Lipscomb [mailto:AndyLipscomb@decosimo.com] Sent: Thursday, August 30, 2007 7:52 AM To: tz@lecserver.nci.nih.gov Subject: RE: EU BST-->GMT issue That looks correct to me. The reversion occurs at 0100 UTC (which is to say 2am BST or 1am GMT), so wallclock times from 1am until 2am are repeated at the fall-back. J Andrew Lipscomb, CPA*ABV, ASA Decosimo Corporate Finance 900 Tallan Building 2 Union Square Chattanooga, TN 37402 423.756.7100 Fax 423.266.6671 www.dcf.decosimo.com Are there any known bugs revolving around the EU timezone not reverting from BST back to GMT? [root@server2 ~]# rm -f /etc/localtime ; ln -s /usr/share/zoneinfo/Europe/London /etc/localtime [root@server2 ~]# date Wed Aug 29 21:42:31 BST 2007 [root@server2 ~]# date -s "Sun Oct 26 00:59:59 2008" Sun Oct 26 00:59:59 BST 2008 [root@server2 ~]# date Sun Oct 26 00:59:59 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:01 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:02 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:03 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:04 BST 2008 [root@server2 ~]# date -s "Sun Oct 26 01:00:01 2008" Sun Oct 26 01:00:01 GMT 2008 Dafydd Rhys-Jones | Software Test Engineer F5 Networks P 206.272.5555 F 206.272.5556 www.f5.com D 206.272.6280 M 206.335.1096
To some extent that problem is unavoidable--1:00:01 "local" time is ambiguous, just as it is in Seattle. It can refer to either 01:00:01Z or 02:00:01Z, and the "date" command defaults to the second occurrence. To get the first occurrence, you have to use the -u switch and specify the time in UTC. J Andrew Lipscomb, CPA*ABV, ASA Decosimo Corporate Finance 900 Tallan Building 2 Union Square Chattanooga, TN 37402 423.756.7100 Fax 423.266.6671 www.dcf.decosimo.com -----Original Message----- From: Dafydd Rhys-Jones [mailto:D.Rhys-Jones@F5.com] Sent: Thu 30 August 2007 11:00 To: tz@lecserver.nci.nih.gov; tz@lecserver.nci.nih.gov Subject: RE: EU BST-->GMT issue If I manually set the time to 1 second after the reversion, it will set it to GMT, however, if I set it before the reversion time, and let it roll over said reversion time, it remains BST. The first command below shows where I set it before rolling over reversion time, and the command at the end after all the date checks showing reversion did not occur is the command where I set it +1 second over reversion time, and it does set it to GMT. Dafydd Dafydd Rhys-Jones | Software Test Engineer F5 Networks P 206.272.5555 F 206.272.5556 www.f5.com D 206.272.6280 M 206.335.1096 -----Original Message----- From: Andy Lipscomb [mailto:AndyLipscomb@decosimo.com] Sent: Thursday, August 30, 2007 7:52 AM To: tz@lecserver.nci.nih.gov Subject: RE: EU BST-->GMT issue That looks correct to me. The reversion occurs at 0100 UTC (which is to say 2am BST or 1am GMT), so wallclock times from 1am until 2am are repeated at the fall-back. J Andrew Lipscomb, CPA*ABV, ASA Decosimo Corporate Finance 900 Tallan Building 2 Union Square Chattanooga, TN 37402 423.756.7100 Fax 423.266.6671 www.dcf.decosimo.com Are there any known bugs revolving around the EU timezone not reverting from BST back to GMT? [root@server2 ~]# rm -f /etc/localtime ; ln -s /usr/share/zoneinfo/Europe/London /etc/localtime [root@server2 ~]# date Wed Aug 29 21:42:31 BST 2007 [root@server2 ~]# date -s "Sun Oct 26 00:59:59 2008" Sun Oct 26 00:59:59 BST 2008 [root@server2 ~]# date Sun Oct 26 00:59:59 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:01 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:02 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:03 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:04 BST 2008 [root@server2 ~]# date -s "Sun Oct 26 01:00:01 2008" Sun Oct 26 01:00:01 GMT 2008 Dafydd Rhys-Jones | Software Test Engineer F5 Networks P 206.272.5555 F 206.272.5556 www.f5.com D 206.272.6280 M 206.335.1096
This is a consequence of the fact that the times from 01:00:00 to 01:00:59 occur *twice* on the day that summer time reverts to standard time. The hours of the day starting from midnight look like this: 00:00 - 00:00:59 BST 01:00 - 01:59:59 BST 01:00 - 01:59:59 GMT 02:00 - 02:59:59 GMT : For the ambiguous times (01:00 - 01:59:59), the date command has to use one or the other instance of that time (either before or after the reversion); it happens to use the one after the reversion. So there are three possible cases when you use the date command on this day: 1. From 00:00 - 00:00:59 -- Uses the time before the reversion (BST), the only reasonable choice. 2. 02:00 and later -- Uses the time after the reversion (GMT), the only reasonably choice. 3. 01:00 - 01:59:59 -- An ambiguous time, could be either BST or GMT; date happens to use the second one, GMT. As a consequence of all this, you simply can't have the date command simply set the time into the interval 01:00 - 01:59:59 BST. If you want to test the reversion, there are two ways that I can see to do it: 1. Set the time to 00:59 (BST), wait one hour plus one minute to observe the reversion. 2. Go through another timezone to get the time you want: A) Set the timezone to GMT. B) Use the date command to set the time to 00:59 (which is 01:59 BST). C) Set the timezone back to London. D) Type 'date' to verify that the time now shows as 01:59 BST. E) Wait one minute to verify the reversion. Regards, Martin Moore -----Original Message----- From: Dafydd Rhys-Jones [mailto:D.Rhys-Jones@F5.com] Sent: Thursday, August 30, 2007 11:00 AM To: tz@lecserver.nci.nih.gov; tz@lecserver.nci.nih.gov Subject: RE: EU BST-->GMT issue If I manually set the time to 1 second after the reversion, it will set it to GMT, however, if I set it before the reversion time, and let it roll over said reversion time, it remains BST. The first command below shows where I set it before rolling over reversion time, and the command at the end after all the date checks showing reversion did not occur is the command where I set it +1 second over reversion time, and it does set it to GMT. Dafydd Dafydd Rhys-Jones | Software Test Engineer F5 Networks P 206.272.5555 F 206.272.5556 www.f5.com D 206.272.6280 M 206.335.1096 -----Original Message----- From: Andy Lipscomb [mailto:AndyLipscomb@decosimo.com] Sent: Thursday, August 30, 2007 7:52 AM To: tz@lecserver.nci.nih.gov Subject: RE: EU BST-->GMT issue That looks correct to me. The reversion occurs at 0100 UTC (which is to say 2am BST or 1am GMT), so wallclock times from 1am until 2am are repeated at the fall-back. J Andrew Lipscomb, CPA*ABV, ASA Decosimo Corporate Finance 900 Tallan Building 2 Union Square Chattanooga, TN 37402 423.756.7100 Fax 423.266.6671 www.dcf.decosimo.com Are there any known bugs revolving around the EU timezone not reverting from BST back to GMT? [root@server2 ~]# rm -f /etc/localtime ; ln -s /usr/share/zoneinfo/Europe/London /etc/localtime [root@server2 ~]# date Wed Aug 29 21:42:31 BST 2007 [root@server2 ~]# date -s "Sun Oct 26 00:59:59 2008" Sun Oct 26 00:59:59 BST 2008 [root@server2 ~]# date Sun Oct 26 00:59:59 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:01 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:02 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:03 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:04 BST 2008 [root@server2 ~]# date -s "Sun Oct 26 01:00:01 2008" Sun Oct 26 01:00:01 GMT 2008 Dafydd Rhys-Jones | Software Test Engineer F5 Networks P 206.272.5555 F 206.272.5556 www.f5.com D 206.272.6280 M 206.335.1096
On 30 Aug 2007, at 15:59, Dafydd Rhys-Jones wrote:
If I manually set the time to 1 second after the reversion, it will set it to GMT, however, if I set it before the reversion time, and let it roll over said reversion time, it remains BST.
But you didn't let it go past the BST -> GMT transition time. That's at 02:00:00 BST, not 01:00:00 BST. There are two points here that may be causing confusion. The first is about the correct transition time, which is as above. The second is that the timestamp you used in your second date setting command, the "Sun Oct 26 01:00:01 2008", is ambiguous. There are two of them. The first is 01:00:01 BST, followed an hour later by 01:00:01 GMT. Date chose the GMT one to use when setting the date. Peter Ilieve peter@aldie.co.uk
"Arthur" == Arthur David Olson <Olson> writes:
Arthur> I'm forwarding this message from Dafydd Rhys-Jones, who sent Arthur> it before joining the time zone mailing list. --ado
From: Dafydd Rhys-Jones [mailto:D.Rhys-Jones@F5.com] Sent: Wednesday, August 29, 2007 5:38 To: tz@lecserver.nci.nih.gov Subject: EU BST-->GMT issue
Hello all, Are there any known bugs revolving around the EU timezone not reverting from BST back to GMT?
[root@server2 ~]# rm -f /etc/localtime ; ln -s /usr/share/zoneinfo/Europe/London /etc/localtime [root@server2 ~]# date Wed Aug 29 21:42:31 BST 2007 [root@server2 ~]# date -s "Sun Oct 26 00:59:59 2008" Sun Oct 26 00:59:59 BST 2008 [root@server2 ~]# date Sun Oct 26 00:59:59 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:01 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:02 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:03 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:04 BST 2008 [root@server2 ~]# date -s "Sun Oct 26 01:00:01 2008" Sun Oct 26 01:00:01 GMT 2008
Maybe I'm missing something, but that looks correct. The changeover is at 01:00 UTC, and BST is an hour ahead so 00:59:59 is an hour and a second prior to the changeover (at 02:00 BST or 01:00 UTC). If I set time via UTC, I can see this: $ date -u -s "Sun Oct 26 00:59:40 2008" Sun Oct 26 00:59:40 UTC 2008 $ date Sun Oct 26 01:59:41 BST 2008 $ date Sun Oct 26 01:59:45 BST 2008 $ date Sun Oct 26 01:00:00 GMT 2008 If the change is supposed to happen at 01:00 BST, then indeed there's a problem, but the file claims 01:00 UTC as the changeover time. paul
That did it: [root@Bip1:LICENSE EXPIRED] config # date -s "Sun Oct 26 00:59:59 GMT 2008" Sun Oct 26 01:59:59 BST 2008 [root@Bip1:LICENSE EXPIRED] config # date Sun Oct 26 01:00:00 GMT 2008 Is there a difference between the way EU runs vs how the US DST runs (revision, wise, not date and time wise). I ask this only because my US DST tests all worked appropriately, along with outlying areas (Virgin Islands, Guam, America Samoa, etc), and the EU one is the only one that acted in this behavior. Thanks! Dafydd Dafydd Rhys-Jones | Software Test Engineer F5 Networks P 206.272.5555 F 206.272.5556 www.f5.com D 206.272.6280 M 206.335.1096 -----Original Message----- From: Paul Koning [mailto:pkoning@equallogic.com] Sent: Thursday, August 30, 2007 8:02 AM To: tz@lecserver.nci.nih.gov Cc: tz@lecserver.nci.nih.gov Subject: Re: FW: EU BST-->GMT issue
"Arthur" == Arthur David Olson <Olson> writes:
Arthur> I'm forwarding this message from Dafydd Rhys-Jones, who sent Arthur> it before joining the time zone mailing list. --ado
From: Dafydd Rhys-Jones [mailto:D.Rhys-Jones@F5.com] Sent: Wednesday, August 29, 2007 5:38 To: tz@lecserver.nci.nih.gov Subject: EU BST-->GMT issue
Hello all, Are there any known bugs revolving around the EU timezone not reverting from BST back to GMT?
[root@server2 ~]# rm -f /etc/localtime ; ln -s /usr/share/zoneinfo/Europe/London /etc/localtime [root@server2 ~]# date Wed Aug 29 21:42:31 BST 2007 [root@server2 ~]# date -s "Sun Oct 26 00:59:59 2008" Sun Oct 26 00:59:59 BST 2008 [root@server2 ~]# date Sun Oct 26 00:59:59 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:01 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:02 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:03 BST 2008 [root@server2 ~]# date Sun Oct 26 01:00:04 BST 2008 [root@server2 ~]# date -s "Sun Oct 26 01:00:01 2008" Sun Oct 26 01:00:01 GMT 2008
Maybe I'm missing something, but that looks correct. The changeover is at 01:00 UTC, and BST is an hour ahead so 00:59:59 is an hour and a second prior to the changeover (at 02:00 BST or 01:00 UTC). If I set time via UTC, I can see this: $ date -u -s "Sun Oct 26 00:59:40 2008" Sun Oct 26 00:59:40 UTC 2008 $ date Sun Oct 26 01:59:41 BST 2008 $ date Sun Oct 26 01:59:45 BST 2008 $ date Sun Oct 26 01:00:00 GMT 2008 If the change is supposed to happen at 01:00 BST, then indeed there's a problem, but the file claims 01:00 UTC as the changeover time. paul
Is there a difference between the way EU runs vs how the US DST runs (revision, wise, not date and time wise). I ask this only because my US DST tests all worked appropriately, along with outlying areas (Virgin Islands, Guam, America Samoa, etc), and the EU one is the only one that acted in this behavior.
The EU rule in the tz data is unusual in specifying UTC transition times. This reflects the way the European Union politicians legislated. They don't much care which timezone a member state is in (and the EU is too big east to west all to be in one) but they do insist that all member states change their clocks, and all at the same time. If you have been used to working with the US rules, which specify wall clock times for the transitions, then this may be what has caused problems with your tests. Peter Ilieve peter@aldie.co.uk
Yep, that's exactly it. Mental note, test EU DST changes by setting UTC. 0] Thanks a lot all! I look forward to bugging you all further! Dafydd Dafydd Rhys-Jones | Software Test Engineer F5 Networks P 206.272.5555 F 206.272.5556 www.f5.com D 206.272.6280 M 206.335.1096 -----Original Message----- From: Peter Ilieve [mailto:peter@aldie.co.uk] Sent: Thursday, August 30, 2007 8:43 AM To: tz@lecserver.nci.nih.gov Subject: Re: EU BST-->GMT issue
Is there a difference between the way EU runs vs how the US DST runs (revision, wise, not date and time wise). I ask this only because my US DST tests all worked appropriately, along with outlying areas (Virgin Islands, Guam, America Samoa, etc), and the EU one is the only one that acted in this behavior.
The EU rule in the tz data is unusual in specifying UTC transition times. This reflects the way the European Union politicians legislated. They don't much care which timezone a member state is in (and the EU is too big east to west all to be in one) but they do insist that all member states change their clocks, and all at the same time. If you have been used to working with the US rules, which specify wall clock times for the transitions, then this may be what has caused problems with your tests. Peter Ilieve peter@aldie.co.uk
participants (7)
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Andy Lipscomb
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Dafydd Rhys-Jones
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Krista Lewis
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Moore, Martin
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Olson, Arthur David (NIH/NCI) [E]
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Paul Koning
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Peter Ilieve