though not a holiday in its own right, is a notable day celebrated in many countries on April 1. The day is marked by the commission of hoaxes and other practical jokes of varying sophistication on friends, enemies and neighbors, or sending them on fools' errands, the aim of which is to embarrass the gullible.
The origins of this custom are complex and a matter of much debate. It is likely a relic of the once common festivities held on the vernal equinox, which began on the 25th of March, old New Year's Day, and ended on the 2nd of April.
Though the 1st of April appears to have been observed as a general festival in Great Britain in antiquity, it was apparently not until the beginning of the 18th century that the making of April-fools was a common custom. In Scotland the custom was known as "hunting the gowk," i.e. the cuckoo, and April-fools were "April-gowks," the cuckoo being a term of contempt, as it is in many countries.
One of the earliest connections of the day with fools is Chaucer's story the Nun's Priest's Tale (c.1400), which concerns two fools and takes place "thritty dayes and two" from the beginning of March, which is April 1. The significance of this is difficult to determine.
Europe may have derived its April-fooling from the French. French and Dutch references from 1508 and 1539 respectively describe April Fools' Day jokes and the custom of making them on the first of April. France was one of the first nations to make January 1 officially New Year's Day (which was already celebrated by many), by decree of Charles IX. This was in 1564, even before the 1582 adoption of the Gregorian calendar (See Julian start of the year). Thus the New Year's gifts and visits of felicitation which had been the feature of the 1st of April became associated with the first day of January, and those who disliked or did not hear about the change were fair game for those wits who amused themselves by sending mock presents and paying calls of pretended ceremony on the 1st of April. In France the person fooled is known as poisson d'avril (April fish). This has been explained as arising from the fact that in April the sun quits the zodiacal sign of the fish. The French traditionally celebrated this holiday by placing dead fish on the backs of friends. Today, real fish have been replaced with sticky, fish-shaped paper cut-outs that children try to sneak onto the back of their friends' shirts. Candy shops and bakeries also offer fish-shaped sweets for the holiday.
Some Dutch also celebrate the 1st of April for other reasons. In 1572, the Netherlands were ruled by Spain's King Philip II. Roaming the region were Dutch rebels who called themselves Geuzen, after the French "gueux," meaning beggars. On April 1, 1572, the Geuzen seized the small coastal town of Den Briel. This event was also the start of the general civil rising against the Spanish in other cities in the Netherlands. The Duke of Alba, commander of the Spanish army could not prevent the uprising. Bril is the Dutch word for glasses, so on April 1, 1572, "Alba lost his glasses." The Dutch commemorate this with humor on the first of April.