9 July 1993: Death of Ron Jones, who directed the Fifth Doctor stories Black Orchid (1982), Time-Flight (1982), Arc of Infinity (1983) and Frontios (1984); and the Sixth Doctor stories Vengeance on Varos (1985) and the one most of us call Mindwarp (1986).
9 July 2007: Death of Peter Tuddenham, who was the voice of the computer in Ark in Space, the voice of the Mandragora Helix in The Masque of Mandragora, and the voice of the Brain in Time and the Rani. Blake's 7 fans remember him also as Orac, Zen and Slave.
ii) broadcast anniversaries
9 July 1966: broadcast of the third episode of The War Machines, which starts with Ben dodging away from the machine confronting him last week; he works out that Polly is under the control of WOTAN, and the episode ends with a failed attack on the warehouse, soldiers fleeing as the War Machine advances on the Doctor, who stands firm and defiant.
9 July 1994: broadcast of Whatever Happened to Susan Foreman?, radio play which sits rather outside standard Who continuity in that Susan, played here by Jane Asher, ends up SPOILER as the European Commissioner for Education, a role that didn't actually exist until 1999. The incumbent is Mariya Gabriel, who was the youngest ever European Commissioner at one point, though has now been overtaken by a Lithuanian.
(Commissioner Mariya Gabriel, not Carole Anne Ford or Jane Asher, obviously.)
9 July 2009: broadcast of the fourth episode of Torchwood: Children of Earth. OMG IANTO!!!!!!
iii) date specified in-universe
9 July 1978: date of birth of Elin Morgan, who almost becomes a victim of the Mayflies in the 2008 Torchwood episode Reset. (Played, uncredited, by Nancy Danks-Smith.)