i) births and deaths
24 September 1939: birth of Maurice Colbourne who played Lytton in Resurrection of the Daleks (Fifth Doctor, 1984) and Attack of the Cybermen (Sixth Doctor, 1985).
24 September 1951: birth of David Banks, who played the Cyber-leader in Earthshock (Fifth Doctor, 1982), The Five Doctors (1983), Attack of the Cybermen (Sixth Doctor, 1985), and Silver Nemesis (Seventh Doctor, 1988) and also wrote the New Adventures novel Iceberg (1993).
24 September 1963: birth of Jaye Griffiths, who played UNIT operative Jac in The Magician's Apprentice and The Zygon Invasion (both Twelfth Doctor, 2015)
ii) broadcast anniversaries
24 September 1966: broadcast of third episode of The Smugglers. It's the Doctor's turn to escape from his captors by magic; and everyone comes to the church for the final confrontation.
24 September 1977: broadcast of fourth episode of Horror of Fang Rock. The alien is revealed as a Rutan; the Doctor destroys its ship with a laser, and Leela's eyes change from brown to blue.
24 September 1993: broadcast of the fifth and, thank God, last episode of The Paradise of Death on BBC Radio. Does it help if I tell you that in the climactic scene, the president's son is mauled to death in an arena by a giant toad? No, I thought not.
24 September 2007: on a much happier note, first broadcast of both parts of Revenge of the Slitheen, which kicks off the first regular season of the Sarah Jane Adventures. Maria and Luke, with Sarah Jane and their new friend Clyde, discover that the Slitheen have taken over their school; but are able to destroy them with vinegar.
24 September 2013: broadcast of Closing Time, ending the regular run of the sixth season of New Who (though there was a Christmas special yet to come). The Eleventh Doctor reunites with Clive and Clive's baby to confront Cybermen under a department store.