i) births and deaths

13 October 1923: birth of Cyril Shaps, who played Viner in The Tomb of the Cybermen (Second Doctor, 1967), Lennox in The Ambassadors of Death (Third Doctor, 1970), Professor Clegg in Planet of the Spiders (Third Doctor, 1974) and the Archimandrite in The Androids of Tara (Fourth Doctor, 1978).

13 October 1997: death of Ian Stuart Black, author of The Savages (First Doctor, 1966), The War Machines (First Doctor, 1966) and The Macra Terror (Second Doctor, 1967).

ii) broadcast anniversaries

13 October 1979: broadcast of third episode of City of Death. The Doctor goes back to Leonardo's studio; and poor old professor Kerensky meets his end.

13 October 2008: broadcast of second episode of Day of the Clown. Clyde defeats the bad guy by telling jokes (great scene with a sea of red balloons being released), and Rani accepts Sarah's invitation to join her team.