While our first introduction to George Lucas’ world was way back in 1977, it was years before the final act of “Star Wars: Episode IV: A New Hope” became the chosen point of reference. The ABY-BBY dating system first came into the “Star Wars” lexicon in 1996, originally appearing in the “Star Wars” Legends continuity of Bill Smith’s “Star Wars: The Roleplaying Game, Second Edition, Revised and Expanded.” However, it wasn’t until after the prequel trilogy that it made it into “Star Wars” canon, with 2014’s “Star Wars Workbook: 2nd Grade Reading.”
In addition to ABY and BBY, there’s another shorthand used to clarify who was doing what and when: BSW4 and ASW4, which stand for “Before Star Wars: Episode IV” and “After Star Wars: Episode IV,” respectively. This dating system debuted in “Star Wars” Legends continuity in Bill Slavicsek’s “A Guide to the Star Wars Universe, Second Edition, Revised and Expanded,” published in 1994, and didn’t appear in “Star Wars” canon until 2020’s “The Star Wars Book.”
Though BSW4 and ASW4 may simply be a variation of ABY and BBY, it’s clear that everything comes back to that pivotal moment in “Star Wars” history when Luke Skywalker (Mark Hamill) blew up a place and went home.