April Fools' Day is celebrated in many countries on April 1 every year. Sometimes referred to as All Fools' Day, April 1 is not a national holiday, but is widely recognized and celebrated as a day when people play practical jokes and hoaxes on each other called April fools.
In Italy, France and Belgium, children and adults traditionally tack paper fishes on each other's back as a trick and shout "April fish!" in their local languages (pesce d'aprile!, poisson d'avril! and aprilvis! in Italian, French and Flemish, respectively). Such fish feature prominently on many late 19th to early 20th century French April Fools' Day postcards.
Here you can read about some jokes made on April Fools' Day
source: Wikipedia
Here you can read about some jokes made on April Fools' Day
source: Wikipedia
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