(CNN)It's not just a pun.
"May the 4th be with you" is a full-fledged unofficial holiday, "Star Wars Day."
Actually, as far as Lucasfilm and Disney are concerned, it's quite official.
So why this day, and what is there to do other than watch it trend on Twitter? (After all, it's apparently important enough to send hardcore fans into a tizzywhen they feel it's been mistreated.)
As legend has it, and according to the origin story recognized by Lucasfilm, the phrase was first used on May 4, 1979, the day Margaret Thatcher took office as UK prime minister. The Conservative party allegedly placed an ad in the London Evening News which read, "May the Fourth Be With You, Maggie. Congratulations."
It took off in the social media age (where it has become a big deal every year) and finally expanded to real-life with events in Toronto. Now, there are events celebrating the day worldwide.
There are online and in-store deals on "Star Wars" merchandise and gaming, "Star Wars" food galore and events where fans are encouraged to dress up or play "Star Wars" trivia or just enjoytheir favorite film franchise.
Vanity Fair is also getting into the spirit of things with an issue filled with new photos and revelations about December's "Star Wars: The Force Awakens."
