30 October 1978: death of Brian Hayles, writer of The Celestial Toymaker (1966), The Smugglers 1966), The Ice Warriors (1968), The Seeds of Death (1969), The Curse of Peladon (1971) and The Monster of Peladon (1974).
30 October 1997: death of Sydney Newman, without whom etc etc.
ii) broadcast anniversaries
30 October 1965: broadcast of "Death of a Spy", the third episode of the story we now call The Myth Makers. Steven and Vicki are imprisoned by the Trojans; the Doctor designs the wooden horse and it is brought into the city.
30 October 1976: broadcast of first episode of The Deadly Assassin. The Doctor returns to Gallifrey to try and prevent the assassination of the President - but fails.
30 October 2009: broadcast of second episode of The Wedding of Sarah Jane Smith. The Doctor, Luke, Clyde and Rani are trapped in a time slip; Sarah persuades Peter to restore normality at the cost of his own life.
iii) date specified in canon
30 October 1938: the Eighth Doctor and Charley Pollard land in Manhattan and encounter Orson Welles, as told in the Big Finish audio Invaders from Mars (2002).