The interval on which to repeat firing the trigger.
- iOS 8.0+
- tvOS 10.0+
- watchOS 2.0+
This value may be
nil if the trigger should not repeat.
The next fire date is calculated by adding the date components to the last fire date, as evaluated in the context of the trigger’s
recurrence. Depending on the calendar, some date components may result in an undefined next fire date.
The minimum recurrence interval is five minutes, and the most precision possible are whole minute values—you may not specify seconds in a recurrence interval. The maximum recurrence interval is five weeks.