April Fools' Day or All Fools' Day, First day of April, named for the custom of playing practical jokes on that date.
Though it has been observed for centuries in several countries, including France and Britain, its origin is unknown. It resembles the Hilaria festival of ancient Rome (March 25) and the Holi festival of India (ending March 31). The custom of playing April Fools' jokes was brought to America by the British. April Fools' Day