Attached is an example of trying two date fields in the same table to a common Date field, which is what would then connect to your calendar. Script below minus the calendar, which would be built like any other calendar.
LOAD recno() as ID, * INLINE [
CreatedDate, DepartureDate, Value
CROSSTABLE (DateType, Date)
,CreatedDate as Created
,DepartureDate as Departure
testMultipleDatesOneCalendar.qvw 152.2 K