Unofficial international holiday
Monkey Day is an unofficial international holiday celebrated on December 14. The holiday was created and popularized in 2000 by artists Casey Sorrow and Eric Millikin when they were art students at Michigan State University. Monkey Day celebrates monkeys and "all things simian", including other non-human primates such as apes, tarsiers, and lemurs. Monkey Day is celebrated worldwide and often also known as World Monkey Day and International Monkey Day.