Proper noun
Opposite Day
(childish) A contrived holiday on which everything is done backwards, for example "yes" means "no".
There's a variety and depth to the song topics I get to write about in children's music and books: being able to write about things I wouldn't normally write about, like a disappointing pancake, or monsters or opposite day is really different than writing about heartbreak and relationships. Lisa Loeb
It’s always Opposite Day, I love that! Source: Internet
Opposite Day can be a whole lot of fun. Source: Internet
Can you imagine what life would be like as an adult if you could call Opposite Day whenever you wanted? Source: Internet
Opposite Day goes both ways, however, and Harden’s defense wound up being the difference in the end. Source: Internet