A cracking selection today:
20 August 1909: birth of Andre Morell, who had only one Whoniverse appearance as Marshal Tavannes in the story we now call The Massacre (First Doctor, 1966), but also ties in with one of my other projects in that he appeared in two Oscar-winning films - as Colonel Green in Bridge on the River Kwai and Sextus in Ben-Hur.
20 August 1916: birth of Bernard Archard, who played Bragen in The Power of the Daleks (Seocnd Doctor, 1966) and Marcus Scarman in The Pyramids of Mars (Fourth Doctor, 1975).
20 August 1932: birth of Anthony Ainley, who played the Master from the last scene of The Keeper of Traken (Fourth Doctor, 1981) till the final Old Who story, Survival (Seventh Doctor, 1989)
20 August 1934: birth of John Davies, who directed The Macra Terror (Second Doctor, 1967)
20 August 1943: birth in Dublin of Sylvester McCoy (original name Percy James Patrick Kent-Smith), who played the Seventh Doctor from Time and the Rani (1987) to Survival (1989) and returned for the 1996 TV movie. He continues to feature in Big Finish audios.
20 August 1962: birth of Sophie Aldred, who played the Seventh Doctor’s companion Ace from Dragonfire (1987) to Survival (1989).
also 20 August 1962: birth of James Marsters, who smoulders through the second (2008) series of Torchwood as Jack's lover and enemy Captain John Hart, though we knew him first as Spike on Buffy. Interesting that he and Sophie Aldred were born on the same day; isn't it odd that we have never seen them in the same room at the same time?
20 August 1969: birth of Barnaby Edwards, main Dalek operator in New Who and also actor, director and writer for Big Finish audios.
ii) production anniversary
I don't usually do these, but this is a significant one.
20 August 1963: first ever production session of Doctor Who, as the opening credits are created.
iii) date specified in-universe
20 August 1572: Steven, trying to find the Doctor, bluffs his way into the Abbot's presence and overhears the plot to assassinate Admiral de Coligny, as shown in The Massacre (First Doctor, 1966).