Effective date
Encyclopedia
An effective date or as of date is the date
upon which something is considered to take effect. This may be different from the date upon which the event actually occurs or is recorded.
Calendar date
A date in a calendar is a reference to a particular day represented within a calendar system. The calendar date allows the specific day to be identified. The number of days between two dates may be calculated. For example, "24 " is ten days after "14 " in the Gregorian calendar. The date of a...
upon which something is considered to take effect. This may be different from the date upon which the event actually occurs or is recorded.