It's not clear whether it's legitimate to specify a "forecast" end date for an encounter as the Encounter.period.end or not, nor is it clear how to distinguish an estimated end date from an actual end date given that there's no date on the Encounter that says when it was last changed.  (_lastUpdated is a technical date and wouldn't necessarily imply that 'estimated' end had been replaced with 'actual' end.)   –   FHIR-22766 added extensions for plannedStartDate  and plannedDischargeDate.  We will abandon that change, and instead create two (non-extension) properties:   plannedStartDate  0..1 dateTime Definition:  The planned start date/time (or admission date) of the encounter. plannedEndDate  0..1 dateTime Definition:  The planned end date/time (or discharge date) of the encounter.   We will also update the existing Encounter.period to be Encounter.actualPeriod, with an update to the definition: Definition : The actual start and end time of the encounter.