April Fools' Day

April Fools' Day, observed every April 1st, is an unofficial tradition of playing practical jokes and spreading harmless hoaxes before revealing the trick with a cheerful "April Fools!" Its exact origins are murky and debated among historians. One popular theory ties it to France's 16th-century switch from the Julian to the Gregorian calendar, which moved New Year's celebrations from late March to January 1st; those who kept celebrating in early April, the story goes, became the butt of jokes and were dubbed "April fools." Other theories point to ancient spring festivals involving role reversal and mischief, such as the Roman festival of Hilaria. Whatever its true origin, the custom spread across Europe and eventually the world, with different countries developing their own flavors of the tradition, from France and Italy's "April fish" pranks involving paper fish stuck to people's backs to elaborate media hoaxes. In the modern era, April Fools' Day has become a favorite occasion for companies, news outlets, and tech platforms to publish elaborate fake product announcements or stories, some of which have become legendary in their own right for how convincingly they fooled the public.