28 February

On February 28 1981, the Fourth Doctor and Adric landed the TARDIS by the side of a motorway to measure a police box. Air hostess Tegan Jovanka stumbled aboard the TARDIS on her way to work at London's Heathrow Airport. The Doctor later confronted confronted one another on the Pharos Project. The Doctor slipped and fell, and then regenerated into his fifth incarnation. (TV: Logopolis, PROSE: Divided Loyalties)

The TARDIS instead landed on a spaceship, where the Fifth Doctor and Adric find Urbankans and human androids. The Doctor saved the Earth from the leader of the Urbankans, Monarch, who had planned to poison Humanity in order to steal equipment needed to travel in time. Having decided they would no longer have any place on Earth, the androids decided to pilot the ship to a new world and continue their lives there. (TV: Four to Doomsday)

Behind the scenes
This was one of very few instances in an old series Doctor Who television story, namely part one of TV: Logopolis, took place on the same day as its broadcast: 28 February 1981. The new series had three such occurrences: 22 April 2011, 26 June 2010 and 25 December 2009.