20 January (releases)


 * 1968 - Episode five of The Enemy of the World was first broadcast on BBC1.
 * 1968 - Part four of the TV Comic story The Witches was first published.
 * 1973 - Episode four of The Three Doctors was first broadcast on BBC1.
 * 1973 - Part one of the TV Action comic story Deadly Choice was first published.
 * 1977 - The novelisation of Carnival of Monsters was first published by Target Books.
 * 1979 - Part one of The Armageddon Factor was first broadcast on BBC1.
 * 1979 - Part six of the TV Comic story The Metal-Eaters was reprinted as a Fourth Doctor story.
 * 1984 - Part two of The Awakening was first broadcast on BBC1.
 * 1994 - Conundrum was first published by Virgin Books.
 * 1994 - DWM 209 was first published.
 * 1996 - Episode one of The Ghosts of N-Space was first broadcast on BBC Radio.
 * 2004 - The audio story The Creed of the Kromon was first released by Big Finish Productions.
 * 2007 - The audio anthology Circular Time was released by Big Finish.
 * 2011 - DWA 201 was first released by BBC Magazines.
 * 2014 - The Time of the Doctor was released on Region 2 DVD and Blu-ray.
 * 2021 - The Fourth Doctor Adventures Series 10: Volume 1 was first released by Big Finish.