credentialengine.org/DurationProfile Entity describing the temporal aspects of a resource. Temporal aspects include exact, minimum, and maximum timeframes of an activity.
http://purl.org/ctdl/terms/description Statement, characterization or account of the entity.
http://purl.org/ctdl/terms/exactDuration Exact period of time of an activity or event.
http://purl.org/ctdl/terms/maximumDuration Maximum amount of time it will take to complete the activity. The value of ceterms:maximumDuration denotes an approximation of duration.