- Star Trek: The Motion Picture
- Star Trek II: The Wrath of Khan
- Star Trek III: The Search for Spock
- Star Trek IV: The Voyage Home
- Star Trek V: The Final Frontier
- Star Trek VI: The Undiscovered Country
- Star Trek Generations
The name of one of the months on the Vulcan calendar. Although Vulcan possesses no moon by which to calculate the local passage of months, as is the practice on Earth, the mutual motions of Vulcan and its co-orbital world T'Khut are used to determine the length of Tasmeen and the other months on the Vulcan calendar.
In an alternate timeline inadvertently created by scientists studying history via the time portal known as the Guardian of Forever, Spock was killed by a wild le-matya on Vulcan's Forge on the 20th day of the Vulcan month of Tasmeen in the Vulcan year 8877 (2237 A.D. on the terrestrial Gregorian calendar).