September 15 is the 258th day of the year.
- 1885, Tuesday (Doc's altered timeline):
- 1967, Friday: The Star Trek episode "Amok Time" premiered. The episode introduced the Planet Vulcan and the Vulcan Salute, both of which Marty implemented in his Darth Vader disguise.
Behind the scenes
The aforementioned event was postulated by Bob Gale and Robert Zemeckis in their official FAQ. If Clara commits suicide in the ravine, it is renamed Clayton Ravine and the space-time continuum is restored to its previous self, the timeline before Doc ever arrived in 1885.