1 December

On Thursday, 1 December 1955, in Montgomery, Alabama, civil rights activist Rosa Parks refused to give up her seat, on a segregated bus, to a white passenger, when the bus became crowded enough that she was required to move. Parks was arrested, leading to the Montgomery Bus Boycott, beginning on 5 December, and, ultimately, the end of racial segregation in America.

Krasko's attempts to alter this crucial event in history were thwarted by the Thirteenth Doctor and her companions, Ryan, Yasmin, and Graham. All four were present on the bus when Rosa Parks took her stand. (TV: Rosa) A guide for time travellers noted that this point in the timestream may be vulnerable to tampering. (PROSE: Time Traveller's Diary)

In 1944, the American Federation of Musicians' recording ban came to an end, allowing Duke Ellington — and others — to once again record their music. (PROSE: Atom Bomb Blues)

In 1981, Sarah Jane Smith began working abroad for Reuters. She returned to the United Kingdom on 14 December. (TV: A Girl's Best Friend)

According to a calendar on the Snowcap base, 1 December 1986 was a Monday. (TV: The Tenth Planet)