21 February (releases)


 * 1970 - Episode four of Doctor Who and the Silurians was first broadcast on BBC1.
 * 1970 - Part six of TV Comic story The Arkwood Experiments was first published.
 * 1976 - Episode four of The Seeds of Doom was first broadcast on BBC1.
 * 1976 - Part four of TV Comic story Virus was first published.
 * 1980 - The novelisation of The Invasion of Time was first published by Target Books.
 * 1981 - Episode four of The Keeper of Traken was first broadcast on BBC1.
 * 2007 - Issue twelve of  Battles in Time, including comic story Beneath the Skin, was first released by GE Fabbri Ltd.
 * 2008 - Issue two of Torchwood Magazine was first published by Titan Magazines.
 * 2013 - Doctor Who Adventures comic story Toothache! was first released in issue three hundred and eight.