What does ABY and BBY mean in ‘Star Wars’?

The destruction of the Death Star
via Disney/Lucasfilm

Keeping up with Star Wars lore and timelines can be an arduous process, as the franchise boasts of meticulous histories of various characters, groups, and locations. Mapping a linear timeline can be pretty tricky, as many events branch out and some are even retconned along the line with the emergence of fresh storylines and character arcs. 

While there are different yardsticks for pinpointing the temporal events in the Star Wars canon, the ABY/BBY date format has emerged as the one most used and accepted. However, it should be kept in mind that the ABY/BBY system is not perfect, as temporal inconsistencies do arise when mapping key events while using this numbering system. 

What do ABY and BBY stand for?

via Disney/Lucasfilm

The ABY/BBY dating system is used to label years in galactic history during the Galactic Civil War, within the context of the Rebel Alliance. The destruction of the Death Star during the Battle of Yavin is typically marked as year zero, as this event marked a major victory against the Galactic Empire. 

Events that occurred in the same year as when the Death Star was first destroyed are dubbed 0BBY and 0ABY, and this emerges as a jumping-off point for events that occurred before or after year zero. 

BBY stands for Before the Battle of Yavin, while ABY stands for After the Battle of Yavin. This notation first appeared in Bill Slavicsek’s A Guide to the Star Wars Universe, released prior to the Prequel trilogy. While Savicsek’s system works fairly well when not keeping the events of the Prequels in mind, the ABY/BBY system quickly falls apart when keeping Prequel-era events in mind.

Does the ABY/BBY notation still make sense for Star Wars canon?

Ben Solo/Kylo Ren
via Disney/Lucasfilm

With the rapid expansion of the franchise, the ABY/BBY notation seems outdated, as there are too many events and tenets to account for. While Yavin was a monumental victory for the Rebel Alliance, in the end, there are later events that hold even greater significance in terms of victory against the Empire. 

For instance, the Battle of Endor in 4 ABY and the Battle of Jakku in 5 ABY emerge as holding more weight, as these events eventually ushered in the New Republic Era. Also, it is worth noting that the system has not been explicitly mentioned in any Star Wars shows (animated or otherwise) and films as of yet, and in a world that is ever-expanding, the system seems out of place. 

If Disney were to expand upon pre-Prequel times or events that occurred post-The Rise of Skywalker (like in the case of the upcoming series The Acolyte, which takes place during the High Republic Era), the ABY/BBY will cause temporal issues in terms of keeping track of events. 

While the system is also used on a collection of maps created by the Ithorian artist Gammit Chond, it applies to only a certain time period in Galactic history and quickly becomes cumbersome when applied to larger, more significant events in Star Wars canon.