18 December

History of the Doctor Who Universe

 * 1926 - Agatha Christie is found at a hotel in Harrogate. (DW: The Unicorn and the Wasp)
 * 1953 - The Sky Gypsy, a small private plane bound from Cardiff to Dublin, disappears. It will reappear in 2007. (TW: Out of Time)

History of Doctor Who

 * 1965 - "Coronas of the Sun" First Broadcast (The Daleks' Master Plan Episode 6)