Schedule trigger
Schedule triggers define when the watch execution should start based on date and time. All times are in UTC time unless a timezone is explicitly specified in the schedule.
Watcher uses the system clock to determine the current time. To ensure schedules are triggered when expected, keep the clocks on all nodes synchronized.
Watcher does not correct for discontinuities in the system clock, in which the clock time jumps forwards or backwards. Discontinuities happen when setting the clock manually, and sometimes when using a time synchronization service if the node's clock is allowed to drift too far out of synchronization. Watches can trigger at unexpected times, or be skipped or repeated, if the system clock experiences a discontinuity.
When specifying a timezone for a watch, keep in mind the effect daylight savings time transitions may have on the schedule, especially if the watch is scheduled to run during the transition. Here’s how Watcher handles watches scheduled during discontinuities:
These occur when the clock moves forward, such as when daylight savings time starts and cause certain hours or minutes to be skipped. If your watch is scheduled to run during a gap transition, the watch is executed at the same time as before the transition.
Example: If a watch is scheduled to run daily at 1:30AM in the Europe/London time zone and the clock moves forward one hour from 1:00AM (GMT+0) to 2:00AM (GMT+1), the watch is executed at 2:30AM (GMT+1) which would have been 1:30AM before the transition. Subsequent executions happen at 1:30AM (GMT+1).
These occur when the clock moves backward, such as when daylight savings time ends and cause certain hours or minutes to be repeated. If your watch is scheduled to run during an overlap transition, only the first occurrence of the time causes to the watch to execute with the second being skipped.
Example: If a watch is scheduled to run at 1:30 AM and the clock moves backward one hour from 2:00AM to 1:00AM, the watch is executed at 1:30AM and the second occurrence after the change is skipped.