X-Day
English
Proper noun
- An annual celebration in the Church of the SubGenius parody religion, falling on July 5 and commemorating the prophesied end of the world on that date in 1998, when alien beings from "Planet X" were to have invaded.
See also
X-Day (Church of the SubGenius) on Wikipedia.Wikipedia
Noun
- Synonym of D-Day (The date of any major event planned for the future.)