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：四月愚人節的確切起源已不可考，不過很多人認為這個節日是起源于1582年前后的法國，在公歷被引進之后——公歷就是我們到今天還在使用的歷法。在早先的歷法中，新年是在3月25日和4月1日之間的。很多人不愿意改變新年的日子，就被叫做“愚人”。會有人給這些人發“愚人信”，發請帖請他們參加不存在的慶祝活動，還會成為惡作劇的對象。
HISTORY: The harassment evolved and spread to other countries, including Britian and Scotland. In England, jokes are only played in the morning as it is considered bad luck to play a practical joke on someone after noon.
歷史：很快就席卷了其他國家，包括大不列顛和蘇格蘭。在英格蘭，只有上午才能和人開玩笑，過了中午的惡作劇會被人認為是不吉利的。
The American colonies likely learned the tradition from the English and French.
美洲的殖民地可能是接受了英國和法國的傳統。