The following events occured on November 12.
- Marty: "You're not gonna' believe this. We have to go back to 1955"
- Doc: "I don't believe it!"
- Marty: "That's right, Doc. November 12th, 1955."
- Doc: "Unbelievable that Old Biff could've chosen that particular date. It could mean that that point in time inherently contains some sort of cosmic significance, almost as if it were the temporal junction point of the entire space-time continuum. On the other hand, it could just be an amazing coincidence."
- — Marty and Doc after discovering when Old Biff handed down the almanac.
1955, Saturday
November 12, 1955 on the time circuits.
November 12, 1955 was one of the most event-filled dates in Hill Valley history.
Original timeline
- George McFly and Lorraine Baines kiss for the first time at the Enchantment Under the Sea Dance.
- The famous Hill Valley lightning storm strikes the Clock Tower at precisely 10:04 p.m.
Altered timeline
- Marty McFly travels back to 1985 after speeding the DeLorean up to 88 miles per hour and leaving behind a pair of fire trails.
- Marty writes a letter to Doc to warn him about his untimely death in 1985.
- George McFly punches out Biff and wins Lorraine's romantic interest back, sparking a change in their future relationship.
- Marty plays Earth Angel and Johnny B. Goode at the Enchantment Under the Sea Dance.
2nd altered timeline
- Biff of the 2015 timeline arrives in the time machine and delivers the Grays Sports Almanac to himself, the incident that was responsible for Biffhorrific 1985.
- The football game UCLA vs. Washington took place ending 19-17, thereby verifying the reliability of the Gray's Sports Almanac.
- Doc and Marty return to 1985 and see it altered; they then travel to 1955 to prevent Biff from giving himself the Sports Almanac.
- Doc Brown encounters his 1955 counterpart while on the way to free Marty from Biff's garage.
- Marty recovers the Gray's Sports Almanac and restores the space-time continuum to its original 1985.
- Time circuits on the DeLorean scramble and the DeLorean is struck by lightning sending Doc to the year 1885.
- Western Union delivers a letter from Doc Brown to Marty instructing him on where to find the time machine and giving him explicit instructions to return to 1985 and destroy the DeLorean.