The origin of April Fools' Day is a bit unclear, but there are several theories about how the tradition of playing pranks on April 1st came to be. Change in the Calendar (1582): One popular theory links April Fools' Day to the calendar reform introduced by Pope Gregory XIII in 1582. Before the reform, Europe used the Julian calendar, and New Year’s Day was celebrated around April 1st. After the switch to the Gregorian calendar, New Year's Day was moved to January 1st. However, some people continued to celebrate the new year on April 1st, and those who had adopted the new calendar would mock them by playing pranks, calling them “April fools.” Ancient Roman Festival (Hilaria): Another theory ties the day to ancient Roman festivals, such as Hilaria, which was celebrated at the end of March. During this festival, people would dress in disguises and play pranks on one another. It was a time for jokes and merriment, somewhat similar to what we do today on April Fools’ Day. French Traditions: In France, April 1st is called “Poisson d'Avril” (April Fish). It’s thought that during the 16th century, some people in France would tape a paper fish to the backs of their friends as a prank. This could have been a playful nod to the idea of being easily caught or tricked, much like the foolishness of someone who falls for a prank. Though its exact origins remain uncertain, April Fools’ Day has become an international tradition of light- hearted trickery and playful deception.