First Contact Day was a holiday celebrated in the Federation on April 5, marking the anniversaries of the flight of the Phoenix and of first contact between Humans and Vulcans in 2063.

While not a major holiday, Naomi Wildman and Neelix planned an elaborate celebration aboard the USS Voyager in 2377, including cheese pierogies, rock and roll music, and a reenactment of the historic first contact by Lieutenant Commander Tuvok. (VOY episode: "Homestead")

In 2381, Admiral Leonard James Akaar planned to have the USS Titan relaunched on First Contact Day, as part of a morale-boosting effort following the Borg Invasion earlier that year. (TNG novel: Losing the Peace)