9 March 1951: birth of Chris Clough, who directed Terror of the Vervoids (1986), The Ultimate Foe (1986), Delta and the Bannermen (1987), Dragonfire (1987), The Happiness Patrol (1988) and Silver Nemesis (1988).
9 March 1997: death of Terry Nation, creator of the Daleks, writer of The Daleks (1963-64), The Keys of Marinus (1964), The Dalek Invasion of Earth (1964), The Chase (1965), Mission to the Unknown (1965), The Daleks' Master Plan (1965-66, with Dennis Spooner who always claimed to have done most of the work), Planet of the Daleks (1973), Death to the Daleks (1974), Genesis of the Daleks (1975), The Android Invasion (1976) and Destiny of the Daleks (1979), as well as the Peter Cushing films Doctor Who and the Daleks (1965) and Daleks - Invasion Earth 2150 AD (1966). Not to mention Blake's 7.
ii) broadcast anniversaries
9 March 1968: broadcast of sixth episode of The Web of Fear. The Doctor's friends rescue him from the Intelligence, but he is annoyed; he had reversed the circuits to drain its mind instead.
9 March 1974: broadcast of third episode of Death to the Daleks. The Doctor and Bellal penetrate the City of the Exxilons.
9 March 1982: broadcast of second episode of Earthshock. The Doctor tracks the androids' signal to a space freighter, goes there by Tardis and is arrested.
9 March 1983: broadcast of fourth episode of Enlightenment. The Doctor and Turlough win the race, and are awarded Enlightenment.
9 March 1984: broadcast of second episode of The Caves of Androzani. The Doctor and Peri have been rescued by Sharaz Jek; they escape him and get mixed up with Stotz's smugglers.
9 March 1985: broadcast of first episode of Timelash. The Doctor and Peri land on Karfel, and the Doctor is forced to go back in time to 1885 to retrieve an amulet.
This is the sixth of the seven dates in the year on which six episodes of Old Who were broadcast.