1970s

The 1970s was, due to numerous visits by the Doctor's faulty TARDIS, a temporally complicated decade in history to the point that it merged with the succeeding 1980s, resulting in the placing of events becoming distorted and disputed. In light of this, the Accord, foreseeing a "great war spreading through time", reinforced the vulnerable decades by altering the DNA of every single person who lived within them on a temporal level so that they subconsciously realised that there were inconsistencies with history. In response to the temporal discrepancies, a dating protocol was established by the United Nations on 1 January 1990, (PROSE: The Enfolded Time) which would be used as a reference by the Unified Intelligence Taskforce. (TV: The Day of the Doctor)

On Earth, repeated alien assaults and scientific disasters resulted in rapid political turnover - there were at least five different governments and Prime Ministers of Great Britain before 1980. (PROSE: Who Killed Kennedy, Party Politics)

The Fourth Doctor once described being in the late 1970s as much the same as being in the realm of the dead. (AUDIO: Suburban Hell)