The true origins of April Fools’ Day are uncertain, but one theory is that it began in 1582, when France adopted the Gregorian calendar. Before then, New Year’s Day fell on March 25, not January 1. And those who continued to celebrate the old New Year (at the beginning of April) were called “fools” by their early adopting peers. Even before this transition, the New Year was associated with the term “fool.” In medieval France, the Feast of Fools fell on January 1. Hijinks abounded at this popular festival: Christian rituals were burlesquely imitated, a fake pope was elected, and high and low officials swapped jobs for a day. Feast of Fools was probably modeled after the similarly themed pagan festival called Saturnalia.
As this French tradition died out during the 16th century (probably good to accept the new calendar by then), a new one sprung up in the form of April Fools’ Day, or All Fools’ Day. In France, the fooled party is called the poisson d’avril, which literally means “April fish.” The customary prank involves pinning a paper fish (also called the poisson d’avril) to to a friend’s back. This isn’t the only April Fools’ custom involving sticking paper to another person’s back. In Scotland, April Fools’ Day is called Gowkie Day—gowk is another name for the cuckoo, which is a common symbol of the fool. The gowkie pranks continue into April 2, Taily Day, when friends traditionally attach a “kick me” sign to their friends’ backs. Oh, tradition.