April Fools’ Day or All Fools’ Day is not an official holiday, but it is still a much-loved tradition among prankers all over the world. While popular, it might come as a surprise that no one really knows when, where or how April Fool’s Day got started. However, there is a certain reason why April 1st has become an international day obsession.

According to one common theory, the tradition dates all the way back to the 16th century in France when Pope Gregory the 13th issued a papal bull mandating a new calendar system for Europe. The Gregorian calendar, as it became known, set the start of the year on January 1st instead of the beginning of spring in late March or early April.

The change traveled slowly in France and many people in rural areas continued to celebrate the new year in spring. These slow adapters became known as April Fools and were designated for pranks and jokes by their countrymen who had held their celebrations months earlier.

For one thing, many people in France had already started celebrating the new year on January 1st long before 1582. The switch occurred gradually all over France, not suddenly after the papal bull. It was even before this change that the new year’s celebration had not been connected specifically to April 1st but with the Easter holiday.

Some theories date the origins of April Fools’ Day centuries earlier to ancient Roman festivals celebrated in the spring such as Hilaria. Eastern cultures have their own versions of the light-hearted tradition including Holi in India—a festival of colors during which people throw colored water or paint on each other.

By the 1700s, English pranksters were celebrating April 1st by playing tricks such as pitting false tales on unsuspecting people or sending them on fake errands. As the holiday became more popular, social media, newspapers, radio and TV stations, and businesses got into the act with false headlines news stories or promotional campaigns.

Some of history’s most famous hoaxes took place in 1957 when the British Broadcasting Corporation (BBC) fooled many people into believing that, in Switzerland, spaghetti grows on trees; and in the USA in 1998, gullible fast-food customers got caught asking for the left-handed burger that a national chain advertised in the paper.

Here are some other solid shenanigans most people used to pull on their friends or their loved ones during this day: switching the clock ahead, tying their shoes together, spraying them with water, hiding their stapler in jelly, surprising them with a water balloon, dressing up in a costume. The celebration of April Fools’ Day may differ from one country to another, but all have a common purpose: to fool the people we love!

Sources: Hoaxes, Britannica