每年4月1日，是西方也是美国的民间传统节日——愚人节。愚人节起源于法国。1564年，法国首先采用新改革的纪年法——格里历(即目前通用的阳历)，以1月1日为一年之始。但一些因循守旧的人反对这种改革，依然按照旧历固执地在4月1日这一天送礼品，庆祝新年。主张改革的人对这些守旧者的做法大加嘲弄。

聪明滑稽的人在4月1日就给他们送假礼品，邀请他们参加假招待会．并把上当受骗的保守分子称为“四月傻瓜”或“上钩的鱼”。 从此人们在4月1日便互相愚弄，成为法国流行的风俗。18世纪初，愚人节习俗传到英国，接着又被英国的早期移民带到了美国。

愚人节时，人们常常组织家庭聚会，用水仙花和雏菊把房间装饰一新。典型的传统做法是布置假环境，可以把房间布置得象过圣诞节一样．也可以布置得像过新年一样，待客人来时，则祝贺他们“圣诞快乐”或“新年快乐”，令人感到别致有趣。

4月1日的鱼宴。也是别开生面的。参加色宴的请帖，通常是用纸板做成的彩色小鱼。餐桌用绿、白两色装饰起来．中间放上鱼缸和小巧玲珑的钓鱼竿，每个钓竿上系一条绿色飘带，挂着送给客人的礼物——或是一个精巧的赛璐珞鱼，或是一个装满糖果的鱼篮子。不言而喻，鱼宴上所有的菜都是用鱼做成的。

在愚人节的聚会上，还有一种做假菜的风俗。有人曾经描述过一个典型的愚人节菜谱：先是一道“色拉”，莴苣叶上撒满了绿胡椒，但是把叶子揭开后，才发现下面原来是牡蛎鸡尾酒；第二道菜是“烤土豆”，其实下面是甜面包屑和鲜蘑；此后上的菜还有用蟹肉作伪装的烧鸡和埋藏在西红柿色拉下面的覆盆子冰淇淋。饭后，客人还可以从丸药盒里取食糖果。

不过愚人节最典型的活动还是大家互相开玩笑，用假话捉弄对方。有的人把细线拴着的钱包丢在大街上，自己在暗处拉着线的另一端。一旦有人捡起钱包，他们就出其不意地猛然把钱包拽走。还有人把砖头放在破帽子下面搁在马路当中，然后等着看谁来了会踢它。小孩们会告诉父母说自己的书包破了个洞，或者脸上有个黑点．等大人俯身来看时，他们就一边喊着“四月傻瓜”。一边笑着跑开去。总之，每逢愚人节这一天，动物园和水族馆还会接到不少打给菲什(鱼)先生成莱昂(狮子)先生的电话，常常惹得工作人员掐断电话线，以便减少麻烦。

如今的愚人节在美国已主要是淘气的男孩子们的节日了。

Unlike most of the other nonfoolish holidays, the history of April Fool's Day, sometimes called All Fool's Day, is not totally clear. There really wasn't a "first April Fool's Day" that can be pinpointed on the calendar. Some believe it sort of evolved simultaneously in several cultures at the same time, from celebrations involving the first day of spring.

The closest point in time that can be identified as the beginning of this tradition was in 1582, in France. Prior to that year, the new year was celebrated for eight days, beginning on March 25. The celebration culminated on April 1. With the reform of the calendar under Charles IX, the Gregorian Calendar was introduced, and New Year's Day was moved to January 1.

 Others, the more obstinate crowd, refused to accept the new calendar and continued to celebrate the new year on April 1. These backward folk were labeled as "fools" by the general populace. They were subject to some ridicule, and were often sent on "fools errands" or were made the butt of other practical jokes.

This harassment evolved, over time, into a tradition of prank-playing on the first day of April. The tradition eventually spread to England and Scotland in the eighteenth century. It was later introduced to the American colonies of both the English and French. April Fool's Day thus developed into an international fun fest, so to speak, with different nationalities specializing in their own brand of humor at the expense of their friends and families.

In Scotland, for example, April Fool's Day is actually celebrated for two days. The second day is devoted to pranks involving the posterior region of the body. It is called Taily Day. The origin of the "kick me" sign can be traced to this observance.

Mexico's counterpart of April Fool's Day is actually observed on December 28. Originally, the day was a sad remembrance of the slaughter of the innocent children by King Herod. It eventually evolved into a lighter commemoration involving pranks and trickery.

Pranks performed on April Fool's Day range from the simple, (such as saying, "Your shoe's untied!), to the elaborate. Setting a roommate's alarm clock back an hour is a common gag. Whatever the prank, the trickster usually ends it by yelling to his victim, "April Fool!"

 Practical jokes are a common practice on April Fool's Day. Sometimes, elaborate practical jokes are played on friends or relatives that last the entire day. The news media even gets involved. For instance, a British short film once shown on April Fool's Day was a fairly detailed documentary about "spaghetti farmers" and how they harvest their crop from the spaghetti trees.

April Fool's Day is a "for-fun-only" observance. Nobody is expected to buy gifts or to take their "significant other" out to eat in a fancy restaurant. Nobody gets off work or school. It's simply a fun little holiday, but a holiday on which one must remain forever vigilant, for he may be the next April Fool!