Path
Period
Id
Period
Cardinality
0 - *
Definition
A time period defined by a start and end date and optionally time.
Comment
This is not a duration - that's a measure of time (a separate type), but a duration that occurs at a fixed value of time. A Period specifies a range of time; the context of use will specify whether the entire range applies (e.g. "the patient was an inpatient of the hospital for this time range") or one value from the range applies (e.g. "give to the patient between these two times"). If duration is required, specify the type as Interval|Duration.
Constraint
All FHIR elements must have a @value or children
If present, start SHALL have a lower value than end
Condition