1985

On Christmas Eve, 1985, the Ninth Doctor was trapped near a Christmas party at Sally Sparrow's aunt's house in Devon, when the TARDIS "burped" and jumped ahead in time 20 years. Using her Christmas essay from 2005, the Doctor wrote messages on the walls and in photographs during the party for Sally Sparrow to read and recorded a video instructing her to pilot the TARDIS back to him in 2005. Sally's future self arrived in the TARDIS, telling her to hit the TARDIS reset button to bring her to the Doctor. The Doctor told the Sally in 2005 to write the essay that she would later (from her point of view) give to him first. (PROSE: What I Did on My Christmas Holidays by Sally Sparrow)

Unknown dates
Lytton contacted the Cybermen in the London sewers. The Sixth Doctor and Peri Brown, searching for a distress signal, were ambushed by the Cybermen, apparently aided by Lytton, and the Doctor was forced to pilot his TARDIS to Telos. (TV: Attack of the Cybermen)

Barbara Chesterton wrote a GCSE textbook called Journeys Through History: A Sourcebook for GCSE for the Associated Exam Board with Ian Martin in which Lady Jane Grey's nine day reign from 10 July to 19 July 1553 was covered. She, the First Doctor and her future husband Ian Chesterton had met Lady Jane shortly after she was deposed by Queen Mary I. (PROSE: The Nine-Day Queen)

Konstantin Chernenko, the General Secretary of the Communist Party of the Soviet Union, died. He was succeeded by the considerably more moderate Mikhail Gorbachev. (AUDIO: Protect and Survive)

Karen Kuykendall created the Tarot of the Cat-People. (PROSE: Invasion of the Cat-People)

Alternative timelines
In an alternative timeline created by the Elder Gods in the hope of destroying Earth, Konstantin Chernenko was succeeded as the General Secretary of the Communist Party of the Soviet Union by the militant hardliner Vladimir Kryuchkov. This ultimately led to the outbreak of World War III on 9 November 1989 between the Soviet Union on the one hand and the United States and its allies including the United Kingdom on the other hand. Given that nuclear weapons were used by both sides, hundreds of millions of people were killed in the conflict. This timeline was ultimately negated by the Seventh Doctor. (AUDIO: Protect and Survive)

In another alternative timeline in which the Beatles did not break up in 1970, the Eighth Doctor's companion Fitz Kreiner saw the band perform at Live Aid. (PROSE: The Gallifrey Chronicles)