A cracking selection today:
20th August 1932: birth of Anthony Ainley, who played the Master from the last scene of The Keeper of Traken (1981) till the final Old Who story, Survival (1989)
20th 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.
20th August 1962: birth of Sophie Aldred, who played Ace from Dragonfire (1987) to Survival (1989) and also continues to feature in Big Finish audios.
also 20th 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?
ii) production anniversary
I don't usually do these, but this is a significant one.
20th August 1963: first ever production session of Doctor Who, as the opening credits are created.
iii) date specified in canon
20th 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, 1966)