The epigraph was spoken by Senator Palpatine in Attack of the Clones. BBY and ABY indicate before the Battle of Yavin and after the Battle of Yavin, respectively. In 25 ABY the New Republic commissioned the New Republic Historical Council to restandardize the Galactic Calendar. The council chose the Battle of Yavin, instead of the Battle of Endor, calling the former the more significant galactic event. From that point on, the year in which the Battle of Yavin occurred was the epoch used for the dating system.
