A representation of a duration of time
The builtin datetime module provides classes for points in time (date, and datetime) as well as durations (timedelta), but it does not account for time durations at a specific point. This module provides Interval, which contains a start and end date or datetime, and a duration timedelta. This is useful for representing calendar events. This module also provides PeriodicInterval which can be used for recurring events, by containing a period timedelta and a count of occurrences (either an int or forever).