http://www.movielabs.org/creativeworks/model#TimePeriod
Class 'Time period'

Class [owl:Class]

Time period

has end date max 1

has unit of time exactly 1

has start date exactly 1

has count exactly 1

Thing

This is a way of specifying the first N [days, weeks, months, years...] starting from a given date.

References
as domain (has unit of time) as range (has time period)