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| ggriffith |
 Posted: Wed Oct 12, 2011 5:24 am Post subject: Daylight Savings and TimeoutControl |
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Acolyte
Joined: 17 Oct 2007
Posts: 67
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| As British summer time ends at 1:00 on 30/10/2011, at which time it becomes 2:00, if I have a TimeoutRequest set to run at 01:30 , will it execute? Also, if I have a sequence of flows, scheduled by TimeoutControls, running at hourly intervals at 00:00, 01:00, 02:00, 03:00, at what time will the jobs execute on 30/10/2011? |
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| lancelotlinc |
| Posted: Wed Oct 12, 2011 5:28 am Post subject: |
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Jedi Knight
Joined: 22 Mar 2010
Posts: 4941
Location: Bloomington, IL USA
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All internal processing should ALWAYS reference GMT. GMT has no adjustment for Daylight Savings Time. NEVER should any internal computational processing EVER use a local time zone.
Local time zones are for humans, not for computers. Computers do not need an extra hour of sleep every year.
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| smdavies99 |
| Posted: Wed Oct 12, 2011 5:58 am Post subject: |
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Jedi Council
Joined: 10 Feb 2003
Posts: 6076
Location: Somewhere over the Rainbow this side of Never-never land.
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| lancelotlinc wrote: |
| All internal processing should ALWAYS reference GMT. GMT has no adjustment for Daylight Savings Time. NEVER should any internal computational processing EVER use a local time zone. |
Except where it does not matter. For example kicking off a cron job/timeout notification every 15 minutes, is oblivious of the season & timezone setting. In this case, hours are irrelevant.
| lancelotlinc wrote: |
| Computers do not need an extra hour of sleep every year. |
Remember... Spring forward into Summer and look back in Autumn.
viz, lose one hour in Spring, gain one hour in the fall. Over a year, there are no hours of sleep lost are there?
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| ggriffith |
| Posted: Wed Oct 12, 2011 7:06 am Post subject: |
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Acolyte
Joined: 17 Oct 2007
Posts: 67
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| I'm not scheduling a flow to start at 15 minute intervals. If I was this would not be an issue. Also the TimeoutControl message is an external message with no concept of GMT so my original questions still stand. |
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| smdavies99 |
| Posted: Wed Oct 12, 2011 8:12 am Post subject: Re: Daylight Savings and TimeoutControl |
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Jedi Council
Joined: 10 Feb 2003
Posts: 6076
Location: Somewhere over the Rainbow this side of Never-never land.
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| ggriffith wrote: |
| As British summer time ends at 1:00 on 30/10/2011, at which time it becomes 2:00, if I have a TimeoutRequest set to run at 01:30 , will it execute? Also, if I have a sequence of flows, scheduled by TimeoutControls, running at hourly intervals at 00:00, 01:00, 02:00, 03:00, at what time will the jobs execute on 30/10/2011? |
BST ends on 30-Oct-2011 AT 02:00. Then the clocks GO BACK one hour and the time is then 01:00 GMT. (One extra hour in Bed...)
IMHO, the easiest was to check that is happening is to try it out for yourself preferably this week.
{see my previous post. You obviously missed the 'spring forward....'}
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| lancelotlinc |
| Posted: Wed Oct 12, 2011 8:22 am Post subject: |
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Jedi Knight
Joined: 22 Mar 2010
Posts: 4941
Location: Bloomington, IL USA
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| ggriffith wrote: |
| I'm not scheduling a flow to start at 15 minute intervals. If I was this would not be an issue. Also the TimeoutControl message is an external message with no concept of GMT so my original questions still stand. |
No, this is not correct. GMT is GMT. All your computational time references should be sync'd to GMT.
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| ggriffith |
| Posted: Wed Oct 12, 2011 8:22 am Post subject: |
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Acolyte
Joined: 17 Oct 2007
Posts: 67
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Sorry Mr Davies
Spring forward , fall back. I know it well, just didn't apply it properly 
Assuming this is spring then and I can't test it for 6 months, does anyone know what will happen.
Can't really apply the same problem to the clocks going back  so I'll have to defer the problem till string. |
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| Vitor |
| Posted: Wed Oct 12, 2011 8:32 am Post subject: |
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Grand High Poobah
Joined: 11 Nov 2005
Posts: 26093
Location: Texas, USA
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| ggriffith wrote: |
| I'll have to defer the problem till string. |
Spotted the problem - you're using character not timestamp.... 
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| ggriffith |
| Posted: Wed Oct 12, 2011 8:37 am Post subject: |
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Acolyte
Joined: 17 Oct 2007
Posts: 67
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Excellent, well spotted, that'll be the problem then 
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| mqjeff |
| Posted: Wed Oct 12, 2011 9:40 am Post subject: |
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Grand Master
Joined: 25 Jun 2008
Posts: 17447
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| ggriffith wrote: |
| Excellent, well spotted, that'll be the problem then |
So what requirement is written in stone that the system clocks on test servers must actually match the current time? |
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| rekarm01 |
| Posted: Thu Oct 13, 2011 2:49 am Post subject: Re: Daylight Savings and TimeoutControl |
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Grand Master
Joined: 25 Jun 2008
Posts: 1415
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| lancelotlinc wrote: |
| Local time zones are for humans, not for computers. |
Unfortunately, local time zones are also for timeout request messages.
| ggriffith wrote: |
| As British summer time ends at 1:00 on 30/10/2011, at which time it becomes 2:00, if I have a TimeoutRequest set to run at 01:30, will it execute? |
The StartTime probably assumes whatever time zone is in effect at the moment when a TimeoutControl node receives the TimeoutRequest message, but there's only one way to know for sure.
| ggriffith wrote: |
| Also, if I have a sequence of flows, scheduled by TimeoutControls, running at hourly intervals at 00:00, 01:00, 02:00, 03:00, at what time will the jobs execute on 30/10/2011? |
Intervals are not dependent on time zones. |
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