i) births and deaths
5th August 1935: birth of Wanda Ventham, who played Jean Rock in The Faceless Ones (1967), Thea Ransome and the Fendahl Core in Image of the Fendahl (1977) and Faroon in Time and the Rani (1987), a nice regular spacing of her appearances over the decades.
5th August 1968: birth of Matt Jones, author of TV stories The Impossible Planet / The Satan Pit (Doctor Who, 2006) and Dead Man Walking (Torchwood, 2008), as well as the excellent Bernice Summerfield story Beyond The Sun (novel, 1997; audio play, 1998).
5th August 1973: birth of Paul Kasey, who has played literally dozens of short monsters in New Who and its spinoffs, and has appeared in 70 episodes of Doctor Who, Torchwood and the Sarah jane Adventures, which I think may be more than anyone else..
Last but by no means least, 5th August 1978 saw the birth of Brian Minchin, script editor for the first two series of Torchwood and for eight episodes of New Who, assistant producer of Torchwood: Children of Earth last year, and producer of the next series of Sarah Jane Adventures. He is also my first cousin. Happy birthday, Brian!
He'll probably kill me for this, but here he is, aged 15, at my wedding in 1993.
ii) broadcast and cinema dates:
5th August 2011: broadcast of The Categories of Life (Torchwood). One of the most horrific moments of the Whoniverse as new-ish character Vera Juarez gets burnt to a crisp.
iii) date specified in-universe
5th August 1975: birth of Jack Harkness's daughter Alice Carter (as revealed in Torchwood: Children of Earth ep 3 in 2009). I'm sure it's pure coincidence that that is also assistant producer Brian Minchin's birthday.