The following events occurred 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 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. One week earlier, George had been struck by a car driven by Lorraine's father, Sam Baines, and Lorraine looked after him during his recovery. Lorraine accepted George's invitation to go the dance. Marvin Berry & the Starlighters play popular music during the entire dance, such as "Night Train" and "Earth Angel".
• During the famous Hill Valley Thunderstorm, a bolt of lightning strikes the Clock Tower at precisely 10:04 p.m., and it hasn't rung since.

Altered timeline

• Doc Brown sets up electrical wiring at Courthouse Square as part of a "weather experiment"
• Marty writes a letter to Doc to warn him about his untimely death in 1985.
• Marty drives Lorraine to the high school dance as part of a scheme to get her and George McFly back together.
• Biff Tannen, angry over a $300 repair bill for his car, comes to the school dance in search of Marty.
• 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.
• Marty McFly travels back to 1985 after speeding the DeLorean time machine up to 88 miles per hour and leaving behind a pair of fire trails.

Second 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 the 1985A timeline.
• The football game UCLA vs. Washington took place ending 19-17, thereby verifying the reliability of the Grays Sports Almanac.

Third altered timeline

• 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, but is able to prevent his younger self from recognizing him.
• Marty recovers and destroys the Gray's Sports Almanac, restoring the space-time continuum to the original 1985 timeline.
• Time circuits on the DeLorean scramble and the DeLorean is struck by lightning, sending Doc to 12:00 p.m. on January 1, 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.
• Immediately after the first Marty had been sent back to October 26, 1985 the second Marty returns to the Courthouse Square and scares the 1955 Doc into fainting.

Appearances

• Back to the Future
• Back to the Future Part II
• Back to the Future Part III
• Back to the Future: The Animated Series
  • "Go Fly a Kite" (Trilogy footage in the live action segment)
• Back to the Future: The Card Game (Mentioned only)
• Back to the Future: The Game
  • Back to the Future: The Game - Episode 3: Citizen Brown (Mentioned on a self tour box.)