For pranksters and mischievous older siblings all around the world, April Fools’ Day, also called All Fools’ Day, is as eagerly anticipated as Christmas.

After all, what other holiday encourages you to think up practical jokes and fool’s errands, from swapping your spouse’s keys to tricking your friend into thinking their car got towed? (Not cool, Steve.)

But how did this odd, prank-centric holiday come to be celebrated in the first place, and why is it called April Fools’ Day?

Where did April Fools’ Day come from?
The true origins of April Fools’ Day remain unknown and are probably lost to history, but theories abound, of course.

One story goes that April Fools’ Day began with France’s 1564 Edict of Roussillon, which decreed that New Year’s Day, historically observed on Easter by Christians, was moved to January 1. Easter is a movable, lunar-based date but often falls in April, so it’s said that early adopters dubbed people celebrating the old New Year “April fools.”

Good one, guys.

Another theory suggests that April 1st became the fool’s holiday due to Geoffrey Chaucer’s 14th century collection, The Canterbury Tales, wherein Chaucer includes a playful reference to “32 March,” or April 1st. However, most scholars consider it to have been a mere copying error.

The holiday also shares some striking similarities to some ancient antecedents, though. The ancient Roman festival, Hilaria, was also a joyful, springtime festival held on or around March 25. Yes, the word hilarious is, aptly enough, related.

Another analog is Holi, a Hindu spring festival celebrated in late March during which people can forgive and forget past faults by throwing colored powder and water on one another.