Much like the introduction of the Gregorian calendar to replace the Julian calendar, so has a series of tweets from Leland Chee, the keeper of the holocron, turned the Star Wars universe on its head.
For those not content to place the whole of the universe in some nebulous "long time ago," there was a way to track events in Star Wars. Until Chee, the Keeper of the Holocron and member of the story group appointed to evaluate the Expanded Universe, tweeted a way of tracking the passage of time between films and TV shows:
That was on August 3rd, and it immediately confused those who have been tracking the Star Wars universe through places like Wookiepedia. The traditional counting of years was based not on The Phantom Menace but on, obviously, A New Hope. Which was given the in-universe name of "The Battle of Yavin." So the Star Wars version of BC/AD (or BCE/CE, depending on what you use) was "BBY/ABY" or "Before Battle of Yavin" and "After Battle of Yavin."
Of course, with most of the Expanded Universe now stricken from canon, it makes sense to reorganize the calendar around the earliest film. But, just like some groups don't mark time with the Gregorian calendar, so too will we still use the old Battle of Yavin calendar. Basically, we're seeing a schism in Star Wars canon. And it won't just be fans, as Chee clarified the situation yesterday:
Two official timelines. Now that seems needlessly complicated.