http://hl7.org/fhir/StructureDefinition/firstCreated|5.2.0

Indicates when this resource ID was first associated with content on this server.

element_id	types
Extension
Extension.extension
Extension.url
Extension.value[x]	instant
Extension
Extension.id	http://hl7.org/fhirpath/System.String
Extension.extension	Extension
Extension.url	http://hl7.org/fhirpath/System.String
Extension.value[x]	instant