7.1.9 Appendix A: Understanding Batch Job Scheduling and Daylight Saving Time (DST)
This documentation outlines how Daylight Saving Time (DST) may affect your scheduled batch jobs when using the Europe/London time zone.
Batch Job Scheduling Behavior
When you schedule a batch job in the application interface, you select a Run Time (example: 4:00 AM) in the Europe/London time zone.
- The batch scheduler internally converts this time to UTC behind the scenes at the time of schedule creation.
- Once this UTC time is set, it remains fixed in the schedule.
Observed Impact During DST Transitions
- During standard time (non-DST): Your job runs at the expected local time (e.g., 4:00 AM local).
- After DST ends (clocks go back one hour, usually in October): The same fixed UTC schedule will trigger one hour earlier in local time.
Examples:
Case 1: Batch scheduled in non-DST range
Table 7-4 Scheduling in non-DST range
| Phase | Europe/ London Time Zone Status | User Expected Schedule Time | Stored UTC Time | Actual Trigger Time (Europe/ London) | Result |
|---|---|---|---|---|---|
| Non-DST | UTC+0 | 8:30 AM | 8:30 AM | 8:30 AM | Correct |
| DST starts | UTC+1 | 8:30 AM | 8:30 AM | 9:30 AM (8:30 AM UTC + 1 hr) | 1 hour delay |
Case 2: Batch scheduled in DST range
Table 7-5 Scheduling in DST range
| Phase | Europe/ London Time Zone Status | User Expected Schedule Time | Stored UTC Time | Actual Trigger Time (Europe/ London) | Result |
|---|---|---|---|---|---|
| DST | UTC+1 | 8:30 AM | 7:30 AM | 8:30 AM | Correct |
| Non-DST starts | UTC+0 | 8:30 AM | 7:30 AM | 7:30 AM (7:30 AM UTC + 0 hr) | 1 hour early |
Customer Impact and Action Required
This behavior may cause scheduled operations, reporting, or data integrations to run at unintended times, particularly for UK users.
The current system does not actively recompute and adjust the UTC time when DST changes. Review and adjust your scheduled jobs around DST changes to ensure they continue to run at your desired local time.