April Fools' day is on the 1st of April. On this day, people like to make jokes. The jokes are to trick people and make them feel silly. Often people tell strange stories or make false plans. If you believe them, then people call you April fool.
There are different stories about the origin of April Fools' Day. The most popular one is that it started in France in 1564. At that time King Charles changed the calendar. He wanted the 1st of January to be New Year's Day. Some people did not agree with the change. They still celebrated the New Year in April. Others laughed at them and called them "fools". Some people followed the new calendar and made fun of the others. They sent the "April fools" foolish New Year greetings and invited them to nonexistent parties.
In the 18th century, April Fools' Day came to England. Then the English and French took it to America. Now people in most western countries celebrate it. （about 190 words）