Opposite Day is an unofficial holiday, that is generally observed whenever it is declared, where every action is modified so that meaning is negated. It is usually observed among children, and rarely lasts an entire day. Once Opposite Day is declared, statements mean the opposite of what they usually mean. Opposite Day can also be declared retroactively to indicate that what was just asserted had the opposite meaning of what was originally intended (similar to the practice of crossed fingers to automatically nullify promises). Paradoxically, the declaration that it is opposite day is negated as well, implying that it is not opposite day. Play has been compared to a children's "philosophy course".
In popular culture
- In the first season of the cartoon SpongeBob SquarePants, an episode was entitled "Opposite Day". In the episode the character Squidward attempts to use the holiday as a method of preventing his neighbors from intruding on the sale of his house.
- An episode of The Grim Adventures of Billy & Mandy was entitled "Opposite Day".
- Indie rock artist Andrew Bird has a song entitled "Opposite Day" on his 2005 album Andrew Bird & the Mysterious Production of Eggs.
- A Sesame Street book entitled Opposite Day was created to teach children about opposites.
- A film entitled Opposite Day starring Ariel Winter is about children switching roles with adults.
- In the "Full Court Dress" episode of Happy Endings, Max complains to Penny about having to babysit his niece and nephew, about the kids' "garbage hipster names", and about their parents' marriage being "doomed" anyway, which he is then revealed to be doing in front of his niece and nephew. In an attempt to cover, Penny tries to explain that Max didn't mean any of it, because it's "Opposite Day". Max then elaborates that their "dad doesn't have a secret Facebook profile under the name Jeffrey Scrotum."
- In the WordGirl episode "Opposite Day", Wordgirl (Becky Botsford) has an Opposite Day party.
- A Cyanide & Happiness animated short shows people behaving differently on opposite day.
- Shelton, Sandi Kahn (2001). Preschool Confidential. Macmillan. pp. 232–234. ISBN 9780312254582.
- Lindsey, Brooklyn E. (2011). Opposite Day: Upside-Down Questions to Keep Students Talking and Listening. Zondervan. p. 69. ISBN 9780310574170.
- "'Grim & Evil' Opposite Day/Emotional Skarr/Look Alive! (2001)". IMDb. Retrieved November 1, 2013.
- "Andrew Bird - The Mysterious Production Of Eggs". Discogs.com. Retrieved November 1, 2013.
- Opposite Day. Publications International, Limited. 2011. ISBN 9781412745673.
- "Opposite Day (2009)". IMDb. Retrieved November 1, 2013.
- "Cyanide & Happiness 'Opposite Day'". Cyanide & Happiness. Retrieved August 21, 2014.