From Federation of Earth Science Information Partners
ISO TM_Primitive is an abstract type. It is replace by GML 3.2 in the XML representation.
|Elements||Definition and Recommended Practice||Examples|
|0..1||Select gml:TimeInstant if there is only a single datetime
Select gml:TimeInstant if there is a beginning and end datetime
Select gml:TimeNode if there is need criteria
Select gml:TimeEdge if there is need criteria
Recommend selecting gml:TimePeriod, because most discovery systems expect a beginning and end date.