End-of-enum marker
Keep repeating in similar intervals measured in UTC, unaffected by Daylight Saving Time. E.g. a repetition of one hour will take one real hour every time, even in a time zone with DST. Leap seconds, leap days and month length differences will still make the intervals different.
Ensure that the time at which the intervals occur stay at the same place in the day, local time. So e.g. a period of one day, referenceing at 8:05AM Europe/Amsterdam time will always reference at 8:05 Europe/Amsterdam. This means that in UTC time, some intervals will be 25 hours and some 23 hours during DST changes. Another example: an hourly interval will be hourly in local time, skipping an hour in UTC for a DST backward change.
Specifies how the period should repeat across the day during DST changes.