Why do we celebrate April Fools’ Day?

One favourite theory ties April Fools’ Day to France moving the start of the year to 1 January in 1564, when people who still celebrated around the end of March were mocked. In France the day is still called poisson d’avril, and children try to stick paper fish on people’s backs. Some scholars point to a joke about 32 March in Chaucer’s Canterbury Tales from the 1390s, while others link it to Roman and spring festivals of mischief. By the 18th century the custom was well known in Britain, where Scotland stretched it to two days. Famous media hoaxes include the BBC’s 1957 report of Swiss farmers harvesting spaghetti from trees.