Doom's Day, also called "Doomsday" is a "holiday" in the Eastern European country of Latveria that commemorates and celebrates the reign of the Fantastic Four's most dangerous archenemy Doctor Doom, and an event in the Marvel Comics universe. It is an eclectic national holiday that is celebrated whenever the ruler of Latveria, Doctor Victor Von Doom, declares it. Thus, the exact date is variable. Apparently, the Latverian people across the country enjoy this day despite the fact that Doom has ordered them to.