Happy Fools day! The first day of April each year is celebrated as April Fools’ Day (or All Fools’ Day) all around the world. The day is even filled with practical jokes and general silliness. You may want to be a little more cautious or skeptical on April 1, since family members, friends, neighbors, colleagues and even teachers may try to tickle your funny bone with a practical joke or a hoax of some kind. But have you ever wondered why we celebrate it? Or how did this tradition of craziness begin?

Well, unfortunately, nobody really knows why we actually do so. It still remains a mystery, although there are many theories about how April Fools’ Day got started.

French Calendar Error

Some historians speculate that April Fools’ Day dates back to 1582, when France switched from the Julian calendar to the Gregorian calendar, causing New Year’s Day to move from April 1st to January 1, as called for by the Council of Trent in 1563. This was decreed by Pope Gregory XIII for all European countries.

According to legend, many people failed to recognize the new calendar or simply didn’t know about it. These people continued to celebrate New Year’s Day on April 1. Eventually, these people became the butt of jokes and hoaxes. Other people began to make fun of these backward “fools” by sending them to look for things that did not exist (called a “fool’s errand”) or tricking them into believing something false. These included having paper fish placed on their backs and being referred to as “poisson d’avril” (April fish), said to symbolize a young, easily caught fish and a gullible person.  This tradition is still observed in Frances, Belgium and French-speaking areas of Switzerland and Canada.

Geoffrey Chaucer’s The Canterbury Tales

Some believe the first association between April 1 and playing tricks can be found in Geoffrey Chaucer’s The Canterbury Tales from 1392. In “The Nun’s Priest’s Tale,” Geoffrey Chaucer talks about the proud rooster Chauntecleer being tricked by a fox on ‘Syn March bigan thritty dayes and two.’

Although Chaucer probably meant 32 days after March (May 2), many readers apparently misunderstood the line to mean March 32 — or April 1.

Ancient Roman Festival ‘Hilaria’

Historians have also linked April Fools’ Day to ancient festivals such as Hilaria, which was celebrated in Rome at the end of March and involved people dressing up in disguises. Hilaria – also known as Roman Laughing Day – is marked on March 25 but people would continue dressing up after that until April 1 hence the link.

Other festivals have also been linked to April Fools Day including India’s Holi festival and the Sizdahbedar in Persian culture where Iranians play pranks on one another.

Mother Nature Fooling With Unpredictable Weather

There’s also speculation that April Fools’ Day was linked to the Spring Equinox, or first day of spring in the Northern Hemisphere, when Mother Nature fools people with changing, unpredictable weather.

Although we can’t really pinpoint how or when April Fools’ Day got its start actually, people still celebrate it with glee. Whatever the gag, it usually ends with the prankster yelling “April Fool!” when the victim falls for it.