In sixteenth-century France, the start of the new year was observed on April first. It was celebrated in much the same way as it is today with parties and dancing into the late hours of the night. Then in 1562, Pope Gregory introduced a new calendar for the Christian world, and the new year fell on January first. There were some people, however, who hadn't heard or didn't believe the change in the date, so they continued to celebrate New Year's Day on April first. Others played tricks on them and called them April fools.

在公元16世纪的时候，法国人的新年是每年的四月一号。那时，他们庆祝新年的方法和我们现在几乎是一样的，人们参加派对，跳舞直到深夜。这种情况一直持续到1562年，罗马教皇格里高利颁布了基督教新历。按照新历，新年从每年的四月一号改为了1月1号。但是当时有人还不知道新历的颁布， 还有的人听说了但是不相信这是真的，他们还是按照老习惯在4月1号这天庆祝新年， 于是其他人就开玩笑，把他们叫做愚人。

In France today, April first is called Poisson d'Avril. French children fool their friends by taping a paper fish to their friends' backs. When the young fool discovers this trick, the prankster yells Poisson d'Avril! (April Fish!)

如今，法国人把四月一号这天叫做四月的鱼。法国孩子会在朋友的背上贴一条纸做的鱼，以此来戏弄别人。当那个被愚弄的小朋友发现以后，开玩笑的人就大叫四月的鱼！

Today Americans play small tricks on friends and strangers alike on the first of April. One mon trick on April Fool's Day, or All Fool's Day, is pointing down to a friend's shoe and saying, Your shoelace is untied. College students set their clocks an hour behind, so their roommates show up to the wrong class - or not at all. Teachers in the nineteenth century used to say to pupils, Look! A flock of geese! and point up. School children might tell a classmate that school has been canceled. Whatever the trick, if the innocent victim falls for the joke the prankster yells, April Fool!

如今，每逢愚人节，不管彼此是否相识，美国人都会开些小玩笑。在愚人节比较常见的把戏是指着别人的鞋子说：你鞋带开了。或者是大学生把自己室友的表调慢一个小时，让那个可怜的室友错过一节课，甚至根本不在课堂上出现。19世纪的时候，在愚人节那天，老师会突然指着远处对学生说：看，那儿有一群鹅。而学生可能会骗同学说学校放假了。不管是什么样的恶作剧，只要那个无辜的受害者中招了，开玩笑的人就会朝着他/她大叫：愚人!

Most April Fool jokes are in good fun and not meant to harm anyone. The cleverest April Fool joke is the one where everyone laughs, especially the person upon whom the joke is played.

愚人节的恶作剧基本上都是善意和搞笑的，并没有什么恶意或要去伤害任何人。最高明的愚人节玩笑能让在场的每个人都捧腹大笑，即使是那个被作弄的人也会忍俊不禁。

The first of April is the day we remember what we are the other 364 days of the year.---- American humorist Mark Twain.

正如美国幽默作家马克吐温所说的只有在四月一号这一天，我们才意识到在一年中其他的364天中我们是多么的愚蠢。