9th September 1960: birth of Hugh Grant who played the Twelfth Doctor in The Curse of Fatal Death (1999). (What do you mean, it's not canon?)
9th September 1968: birth of Julia Sawalha, who played Emma in The Curse of Fatal Death (1999). (Exactly.)
ii) broadcast anniversaries
9th September 1967: broadcast of episode 2 of Tomb of the Cybermen. The expedition explores the vaults, and the Cybermen awake!
9th September 1978: broadcast of episode 2 of The Ribos Operation. The Doctor and Romana escape the shrivenzale, but are captured by the Graff Vynda-K, who orders their immediate execution.