First contact between Humans and Vulcans occurred in 2063. In Star Trek history, the meeting happened on April 5 after Zefram Cochrane successfully tested humanity’s first warp-capable spacecraft.
Cochrane’s ship, the Phoenix, launched from Earth near Bozeman, Montana, during the planet’s recovery from World War III. Its warp flight produced a detectable signature that attracted the Vulcan survey vessel T’Plana-Hath to Earth.
The event is depicted at the end of Star Trek: First Contact. The film’s 24th-century crew travels back in time to stop the Borg from preventing the flight, because the warp test is the key event that begins humanity’s involvement in interstellar civilization.
The date is sometimes confused with April 4, 2063, when the Enterprise-E arrives in Earth’s past. That is the day before the historic flight; the actual Vulcan landing and official first contact take place on April 5. The encounter eventually helps lead to the formation of the Federation.