Monkey Day Date in the current year: December 14, 2024

Celebration of Monkey Day was started as a joke. In 2000 artist Casey Sorrow, then student at Michigan State University, made a note on friend's calendar “Monkey Day” and celebrated the holiday with other students of the university. The holiday gained popularity when Sorrow and his fellow students included Monkey Day in their comic strips Fetus-X and artwork and started promoting the holiday online.

Monkey Day gained enormous popularity among people in the USA, Canada, Mexico, Germany and the United Kingdom. Annually the activists organize different events related to monkey. Individuals are also encouraged to celebrate this holiday by organizing costume parties or holding different competitions. Other events include auctions and educative events that help draw public attentions to the issues concerning animal rights, medical research and protection of monkeys.