Although not officially recognized by all nations, the Imperial Calendar is the most commonly used system by which the years are measured. The year 0 was the year in which the Empire was officially founded which often leads to confusion as some believe this date to be prior to The Three kingdoms war in which the Kingdom of Haram existed. Unfortunately the precise date of the kingdom's founding is unknown and so it is placed at the beginning of The Three kingdoms war (3 B.F.). Every date prior to the year 0 is known as _ B.F. meaning "Before Founding" and every date after is _ A.F. meaning "After Founding".