A long time ago in a galaxy far, far removed from the current output of Star Wars stories now that Disney owns the franchise, an unlikely source created a standard for the measurement of dates in Star Wars canon.
The system uses a well-known event in the Star Wars galaxy as a reference point, with BBY and ABY standing for “Before Battle of Yavin” and “After Battle of Yavin,” that battle being the first onscreen battle in all of Star Wars (the climax of A New Hope, to be exact), in which the Rebel Alliance destroyed the first Death Star. This pivotal moment represents year “zero” in Star Wars chronology. BBY and ABY first appeared in the second edition of the reference book A Guide to the Star Wars Universe by Bill Slavicsek, published in 1994, before George Lucas began work on the Prequel Trilogy. The BBY/ABY format has been the de facto standard ever since.
Especially in the vast expanse of space between the release of Return of the Jedi in 1983 and The Phantom Menace in 1999, this dating standard was welcomed by fans as a uniform way to delineate the major plot points of the saga. The Old Republic, for example, took place circa 25,000–1,000 BBY, the Clone Wars took place 22–19 BBY, and the Battle of Exegol took place in 35 ABY. From the Hundred-Year Darkness to the Battle of Crait, every event in Star Wars canon falls along the same timeline.
Is BBY/ABY Canonical?
Other measurement systems were used before the BBY/ABY format gained popularity, and others have been introduced since. For example, The Thrawn Trilogy by Timothy Zahn, published just before Slavicsek’s guide introduced BBY/ABY, used the Battle of Endor as a year-zero event. On the BBY/ABY timeline, the Battle of Endor took place in 4 ABY, and is arguably a more significant victory for the Rebel Alliance and the galaxy in general, because the destruction of the second Death Star signaled the end of the Galactic Empire.
Since their acquisition of Lucasfilm in 2014, Disney has introduced a BSI/ASI format in reference to events that took place before or after the Starkiller Incident in The Force Awakens. As cataclysmic as it may have been (the entire Hosnian star system was annihilated), whether the Starkiller Incident was as significant to the Skywalker Saga or the timeline of Jedi and Sith as the Battle of Yavin or the Battle of Endor is debatable.
Disney seems to want to establish the events of The Force Awakens as a new anchor point for the Saga, shifting the date of every event 34 years forward. While it follows canonical events, the BBY/ABY timeline is technically a Legends concept—that is, part of the history of Star Wars that Disney specifically deemed non-canon when they acquired the franchise. But no measurement system has ever been as widely accepted by the Star Wars community as BBY/ABY.
(featured image: Lucasfilm)
