For an assignment, the first date value found in the following sequence of fields will be the Calculated Assignment Start Date in the Assignment Derived Calculations view.
ASSIGNMENT!START_DATE,
ASSIGNMENT_DESTINATION!START_DATE,
ASSIGNMENT!EFFECTIVE_DATE,
AUTH_STAGE_ASSIGNMENT!EFFECTIVE_DATE,
ASSIGNMENT! HOME_COUNTRY_DEPARTURE_DATE,
AUTH_STAGE_ASSIGNMENT!HOME_COUNTRY_DEPARTURE_DATE,
ASSIGNMENT!HOST_COUNTRY_ARRIVAL_DATE,
AUTH_STAGE_ASSIGNMENT!HOST_COUNTRY_ARRIVAL_DATE
For remote work or business travel, the start date will be taken from the Assignment Destination table. If there is an Assignment Effective date, it will be used instead.