This is the ValueSet that contains all the codes in hl7VS-whichDate-timeStatusQualifier (http://terminology.hl7.org/ValueSet/v2-0157) and hl7VS-whichDate-timeStatusQualifier (http://terminology.hl7.org/ValueSet/v2-0157). E.g. what you have to deal with if you get resources containing codes in either of them