What is the origin of April Fools’ Day?
Well, because some tall tales have been told to take credit for the day of pranks and jokes, no one is quite sure. According to Wikipedia, one theory is that until 1564, April 1 was counted as the first day of the year in France. When King Charles IX changed that to Jan. 1, some people stayed with April 1. Those who did were called “April Fools” and were taunted by their neighbors.
Or there’s this: Iranians play jokes on each other on the 13th day of the Persian new year (Nowruz), which falls on April 1 or April 2. This day, celebrated as far back as 536 BC, is the oldest prank tradition in the world still alive today, and has led many to believe that April Fools’ Day has its origins there.