Disney has reset the Star Wars timeline around the sequel trilogy. Every event in Star Wars history has traditionally been related to the Battle of Yavin 4, which took place in the first Star Wars movie. Thus Star Wars: The Force Awakens is dated 34 ABY (After Battle of Yavin).

Of course, the in-universe calendar is different - but, amusingly, it’s still linked to the Battle of Yavin 4, just in a more esoteric way. Pablo Hidalgo’s in-universe reference books use a dating system referred to as CRC, dates the Battle of Yavin as 7977 - the 1977 release of Star Wars, plus 6,000. According to this calendar, Star Wars: The Force Awakens takes place in 8011CRC, and Star Wars: The Rise of Skywalker is just a year later, in 8012CRC.

Surprisingly, the Star Wars: The Rise of Skywalker Visual Dictionary unveils a new dating system oriented around Disney’s sequel trilogy. Star Wars: The Force Awakens is referred to as the “Starkiller Incident,” meaning the calendar divides around BSI (Before Starkiller Incident) and ASI (After Starkiller Incident). So the movies are dated like this:

  • Star Wars: Episode I - The Phantom Menace - 66BSI Star Wars: Episode II - Attack of the Clones - 56BSI Star Wars: Episode III - Revenge of the Sith - 53BSI Solo: A Star Wars Story - mainly 44BSI Rogue One: A Star Wars Story and Star Wars - 34BSI The Empire Strikes Back - 31BSI Return of the Jedi - 30BSI Star Wars: The Force Awakens and Star Wars: The Last Jedi - 0 Star Wars: The Rise of Skywalker - 1ASI

On reflection, it’s easy to understand why Disney and Lucasfilm have reset the calendar at this point. Star Wars: The Rise of Skywalker features the return of Emperor Palpatine, meaning there’s a clear line of continuity running all the way through the Skywalker Saga. This new dating system allows viewers to understand that Palpatine became Chancellor 67 years ago, founded the Empire 54 years ago, and was killed 31 years ago.

At the same time, though, this new system is unlikely to stick. The simple fact is that it all began in 1977, with the first Star Wars, and everything really does flow from the moment Luke Skywalker decided to leave Tatooine and unwittingly rewrite the history of the galaxy. That’s why even Hidalgo’s in-universe calendar revolves around 1977 in its own way; because he’s smart enough to know any other dating system is not going to be accepted in the long run by a fandom who dislike change. Hopefully this new calendar will appear once, in the Star Wars: The Rise of Skywalker Visual Dictionary, and then will be discarded.

More: Star Wars: The Rise of Skywalker - Every Easter Egg & Reference