TimeSlice is useful to get events in specified time extents but may be useless
for zone generation as it may contain zone end events for zones that started before
the slice. Even if a time slice starting exactly at a zone start time is used, a
preceding zone may have ended in the same hectonanosecond.
A 'slice' of events based on start end end time.
Produced by ChunkyEventList.timeSlice().
TimeSlice is useful to get events in specified time extents but may be useless for zone generation as it may contain zone end events for zones that started before the slice. Even if a time slice starting exactly at a zone start time is used, a preceding zone may have ended in the same hectonanosecond.