19654 B.C. was a year in the Pleistocene era, more commonly known as the Ice Age.
- Monday, January 8: Marty McFly and Doc Brown are temporarily left stranded by Marcus Irving. They manage to escape sabre-tooth tigers shortly before Irving returns to bring them forward to 1997 in his Yugo time machine. He was afraid of the butterfly effect their presence could cause that far in the past.