ALSO KNOWN AS: All Fool's Day
ORIGIN: the exact origin of April Fool's Day isn't known, but many think it began in France around 1582 with the introduction of the Gregorian Calendar, which is the most widely used calendar today. In previous calendars, New Year's Day was between March 25 and April 1. Many people refused to change the New Year's celebration day and were dubbed "fools." They were sent on "fool errands," sent invitations to nonexistent parties and had other practical jokes played on them.
起源：四月愚人节的确切起源已不可考，不过很多人认为这个节日
