How April fools day started?

Origin of April Fools' Day

There are several theories about the origin of April Fools' Day. The most popular explanation is the switch to the Gregorian calendar. In 1582, Pope Gregory XIII ordered a new calendar (the Gregorian Calendar) to replace the old Julian date. Prior to that, the new year was celebrated for eight days, from March 25 until April 1. Those who did not adapt the new calendar system, or did not learn about it, continued to celebrate New Year's Day on April 1. Other people began to make fun of these traditionalists, sending them on "fool's errands" or trying to trick them into believing something false.

These April "fools" were subjected to ridicule and practical jokes and the tradition was born. These pranks were first called Poisson d'avril (April fish) because a young, naive fish is easily caught. A common prank was to hook a paper fish on the back of someone as a joke. This evolved over time and a custom of prank-playing continues on the first day of April.