http://hl7.org/fhir/StructureDefinition/codesystem-effectiveDate|5.2.0

This is the first date-time when the value set version becomes active, so this value is present on Inactive value set versions as well. The start Date_time is expected to be as of 0001 UTC of the Effective Date.

Structure JSON Dependencies FHIRSchema Other Versions Dependant (0)Elements Summary

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