April Fool's Day, also known as All Fool's Day, is a day when people play practical jokes on others and engage in trickery. The tradition is believed to have originated in France in the 16th century. Originally, New Year's Day was celebrated from March 25 to April 1, but when King Charles IX changed the date to January 1 in the mid-1560s, some people continued to celebrate the old New Year's Day on April 1st, which led to them being called "April Fools."
In France, April Fools are called "April Fish" （Poisson d'Avril）. A common prank is to tape a paper fish to someone's back and then shout "Poisson d'Avril!" when they discover it.
Other countries have different customs. In England, tricks can only be played in the morning, and if a trick is played on someone, they are called an "April Fool."
The origins of April Fool's Day are not entirely clear, but it is believed to be a result of various historical and cultural events, including the change in New Year's Day celebrations and religious conflicts. Some theories suggest that it may have originated from ancient festivals or religious ceremonies, while others believe it is simply a way for people to have fun and play pranks on each other.
