The Movie Timeline - be obsessive, be very obsessive
Black Christmas - timeline
Billy Edward Lenz is born with a rare medical condition that gives him yellow skin.
Thursday 24th December: Billy Edward Lenz has his first Christmas. His mother hates him and crushes an ornament to pieces by him.
Saturday 9th February: Leigh Crosby is born.
Thursday 17th July: The date on a picture of the Apollo-Soyuz U.S.-Soviet Space Link-up.
Wednesday 24th December: Mrs. Lenz kills her husband. She and her new boyfriend bury him in an underground crawlspace under the house. Billy, having witnessed this, is locked in the attic.
Friday 24th December: Billy is raped by his mother when her lover is impotent.
September: Agnes Lenz is born.
Leigh's half-sister Claire Crosby is born.
Tuesday 24th December: Billy disfigures Agnes and kills his mother and her new husband. He makes cookies out of his mother's flesh.
Wednesday 25th December: Billy Lenz is sent to a mental asylum.
Barbara MacHenry is a Delta Alpha Kappa housemother. Leigh Crosby is in the sorority.
Monday 18th January: Leigh Colvin's ID is issued. (Manchester, New Hampshire)
Leigh Crosny leaves Delta Alpha Kappa.
Sunday 24th December: Billy Lenz escapes the mental asylum and kills former Delta Alpha Kappa sorority girls with the help of Agnes.
Monday 25th December: Survivors Kelly Presley and Leigh Colvin are taken to a hospital. Agnes stabs Leigh in the neck, killing her. Kelly kills Agnes with a defibrillator and pushes Billy downstairs, where he is impaled on the tip of a Christmas tree.
Leigh's divorce is finalized.