For an assignment, the first date value found in the following sequence of fields will be the Calculated Assignment End Date in the Assignment Derived Calculations view.
ASSIGNMENT!ACTUAL_END_DATE,
ASSIGNMENT_DESTINATION!END_DATE,
AUTHORIZATION!ACTUAL_END_DATE,
ASSIGNMENT!CURRENT_EXTENSION_END_DATE,
AUTHORIZATION!CURRENT_EXTENSION_END_DATE,
ASSIGNMENT!SCHEDULED_END_DATE,
AUTHORIZATION!SCHEDULED_END_DATE,
ASSIGNMENT!HOST_COUNTRY_DEPARTURE_DATE,
AUTHORIZATION!HOST_COUNTRY_DEPARTURE DATE