April Fools' Day

April Fools' Day (April 1) is a "holiday" celebrated in many english-speaking countries in the world, and it's widely recognized and celebrated as a day when people play practical jokes on each other.

Many possible origins have been discussed throughout the years, some of them are as follow:

• In Chaucer's Canterbury Tales (1392), the "Nun's Priest's Tale" is set "Syn March bigan thritty dayes and two". It is believed to be a copying error, the right transcription being, "Syn March was gon". Thus, the passage originally meant 32 days after April, i.e. May 2. Readers apparently misunderstood this line to mean "March 32", i.e. April 1.
• In 1508, French poet Eloy d'Amerval referred to a poisson d’avril (April fool, literally "April fish"), a possible reference to the holiday.
• In 1539, Flemish poet Eduard de Dene wrote of a nobleman who sent his servants on foolish errands on April 1. In 1686, John Aubrey referred to the holiday as "Fooles holy day", the first British reference.
• On April 1, 1698, several people were tricked into going to the Tower of London to "see the Lions washed".

However, the most plausible one took place during the ruling of Charles IX of France (1550 - 1574).

During the Middle Ages, all through France and many other European towns, the New Year was celebrated on March 25. In some places of France, the festivity lasted for one week, thus ending on the 1st of April. In 1564, it was decreed that New Year's Day should be moved to January 1st, following the calendar of Pope Gregory XIII, however most of the french colonies in the United States kept on celebrating the festivity from March 25 to April 1.

By the 18th century, people following the Gregorian calendar made fun of those who celebrated the New Year during the first week of Spring, and considered them to be "fools". Afterwards, to avoid being ridiculized and treated as fools, people decided to turn the day into a "mocking day", and thus was born the tradition of making jokes on the first day of April.

[Source: Wikipedia.org]