There is a belief that the start of April Fool’s Day started in 1582 when France made a switch from the Julian calendar to the Gregorian calendar. The Julian calendar would start the new year at the end of March. When the switch was made to the Gregorian calendar the new year started on January 1. There were people who did not get the information quickly and therefore were called “April Fools” by others. The saying got carried over to other countries and it, therefore, turned into playing jokes on one another on April 1.