April Fools' Day is an observance which takes place in many western countries every April 1. It is traditionally known as April Fools' Day or All Fools' Day (aka Poisson d'Avril — "April Fish" — in France). It's a day when humor reigns and harmless pranks, practical jokes, and hoaxes are sanctioned. Customary practices range from simple tricks played on friends, family, and coworkers to elaborate media hoaxes.

The origins of April Fools' Day are obscure. Historical records exist of ancient traditions in many cultures linking this time of year to merriment and tomfoolery.

One of the great April Fools' Day media hoaxes of all time was perpetrated in 1957 by the BBC, which reported on its news program, Panorama, that Switzerland was experiencing a bumper spaghetti harvest that year thanks to favorable weather and the elimination of the dread "spaghetti weevil." Staged video footage showing happy peasants plucking strands of pasta from tall trees was so convincing that many viewers actually called the network to ask how they could grow their own.