1.5.3 Using JP1/AO in time zones affected by daylight saving
When you use JP1/AO in a time zone where daylight saving time applies, the following start times are affected:
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Start times of services submitted for scheduled execution
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Start times of services submitted for recurring execution
The explanation below uses the example of Central Daylight Time (USA and Canada). The start and end times for CDT are as follows:
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Start of daylight saving
2:00:00 on second Sunday in March
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End of daylight saving
2:00:00 on first Sunday in November
- Organization of this subsection
(1) Switching from standard time to daylight saving time
The timing with which tasks start after the system switches from standard time to daylight saving time is determined from the start time set for the task, and the time difference between standard and daylight saving time. At 2:00:00 on the second Sunday in March, the clock switches to 3:00:00. This means that the period from 2:00:00 to 2:59:59 standard time is skipped over. If you set up a task to start within this period, it will start at 3:00:00 daylight saving time.
If you set it up to start at 3:00:00 or later standard time, the task will start at 3:00:00 or later after the transition to daylight saving time has taken place. This means that the task will start, in relative terms, one hour ahead of its scheduled start time.
The following table shows how tasks are scheduled around the transition from standard time to daylight saving time.
|
Start time setting |
1:59:59 or earlier |
2:00:00 to 2:59:59 |
3:00:00 or later |
|
Actual start time |
Executed at 1:59:59 or earlier standard time |
Executed at 3:00:00 daylight saving time |
Executed at 3:00:00 or later daylight saving time |
(2) Switching from daylight saving time to standard time
The timing with which tasks start after the system switches from daylight saving time to standard time is determined from the start time set for the task, and the time difference between standard and daylight saving time. When the time reaches 2:00:00 on the first Sunday of November, the clock switches to 1:00:00 standard time. The result is an extra hour in standard time, from 1:00:00 to 2:00:00. Tasks that were scheduled to start between 1:00:00 and 1:59:59 are started at the scheduled time in daylight saving time, and are not started again after the transition to standard time.
If you set up a task to start at 2:00:00 daylight saving time or later, it will start at 2:00:00 in standard time, after the transition to standard time has taken place. This means that the task will start, in relative terms, one hour later than its scheduled start time.
The following table shows how tasks are scheduled around the transition from daylight saving time to standard time.
|
Start time setting |
0:59:59 or earlier |
1:00:00 to 1:59:59 |
2:00:00 or later |
|
Actual start time |
Executed at 0:59:59 or earlier daylight saving time |
Executed between 1:00:00 and 1:59:59 daylight saving time |
Executed at 2:00:00 or later standard time |