Funny you should ask:
April Fools’ Day has been around for centuries, but its origin is obscure.
To all the pranksters in the world, congratulations. The one day in the year you have permission to fool your friends and families is Saturday.
Although April Fools’ Day is not a public holiday in any country, it has been celebrated globally for centuries. The roots are fuzzy. Some say it started as a way to mark a changing season. Others say it’s tied to a calendar shift in France in the 1500s that moved New Year’s Day from the end of March to Jan. 1, “fooling” some who stuck to the original calendar.
“The origin of April Fools’ Day is very obscure. There is a variety of different explanations, reasons and causes, so I can’t give a definite answer,” said Joseph Boskin, professor of history at Boston University and author of Humor and Social Change.
Alex Boese, author of The Museum of Hoaxes: A History of Outrageous Pranks and Deceptions, speculates it probably originated as a festival to celebrate spring.
In the 19th century, it was considered a children’s holiday in Europe and North America. Children got to misbehave for a day, despite their parents’ annoyance. Streets in London and New York were filled with children known as “street urchins,” who devised all kinds of mischief.
In the 20th century, April Fools’ Day evolved into a global holiday, and journalists started to embrace it, using it to show off their creativity by writing crazy stories. In the 21st century, companies such as Google, Virgin and BMW discovered it’s fun to connect to customers with a sense of humor, according to Boese.
April Fools’ Day is crucial in society because people need at least one out of 365 days to express their inner clown in a pro-efficiency environment where playfulness is not always revered, Boskin said.
Allowing people to misbehave and break social rules for one day reinforces the social order, Boese said.
“A glimpse of what chaos would look like reminds everyone why they need to behave for the rest of the year,” he said.