Opposite Day

This article is about the game. For the comedy film of 2009, see Opposite Day (film). For the parliamentary mechanism, see Opposition day.

Opposite Day is sometimes declared retroactively to indicate that something which has just been said now has the opposite of its original meaning (similar to the practice of crossed fingers to automatically nullify promises).

The game has also been compared to a children's "philosophy course."

Self-referential paradox

Opposite day causes a self referential paradox. On opposite day, it could be said that "Today is opposite day." Therefore, it is not opposite day, but if you say it is a normal day it would be considered a normal day, which contradicts the fact that it has previously been stated that it is an opposite day.