What is the story behind April fools? Why is April Fools’ Day April 1?

Think of all the laughs you've had on April Fool's Day, whether it was for a harmless prank or because you were fooled. From practical jokes to fake news, April Fool's Day is an opportunity to have some good old-fashioned fun that usually doesn't have any lasting effects. So why do we celebrate this day? On April 1, 1582, France adopted the Gregorian calendar which replaced the Julian calendar in use since 45 BC.