While the holiday’s exact origins remain unknown, the first day of April became associated with hoaxes after France switched from the Julian calendar to the Gregorian calendar in 1582.

Before the change, New Year’s celebrations were scheduled near the spring equinox, with festivities starting March 25 and ending April 1. After Pope Gregory’s sudden shift in time-keeping, many Frenchmen were slow to embrace the new start on January 1. These holdouts were annually pranked and ridiculed by their fellow countrymen as “April Fools.”

By 1700, the holiday’s traditions of deceit and mockery had spread to Great Britain but completely devoid of their original intent to discredit inferior calendars. The British, after all, continued to commemorate New Year’s Day on March 25 until Parliament finally adopted the Gregorian calendar in 1752.

References

“April Fools’ Day.” History.com. A&E Television Networks, November 24, 2009. https://www.history.com/this-day-in-history/april-fools-tradition-popularized.

History.com Editors. “April Fools’ Day.” History.com. A&E Television Networks, March 30, 2017. https://www.history.com/topics/holidays/april-fools-day.

“Libguides Home: Colonial Records & Topics: 1752 Calendar Change.” 1752 Calendar Change – Colonial Records & Topics – LibGuides Home at Connecticut State Library, Division of Library Development. Accessed March 29, 2022. https://libguides.ctstatelibrary.org/hg/colonialresearch/calendar#