23 September 1949: birth of Floella Benjamin (now Baroness Benjamin of Beckenham) who played the recurring character Professor Rivers in the first three seasons of the Sarah Jane Adventures.
23 September 1959: birth of Frank Cottrell Boyce, who wrote In the Forest of the Night (Twelfth Doctor, 2014) and Smile (Twelfth Doctor, 2017). (And much ese, including the 2012 Olympics opening ceremony.)
ii) broadcast anniversaries
23 September 1967: broadcast of fourth episode of Tomb of the Cybermen. The Cybermen kill Kaftan; Toberman helps the others to freeze the Cybermen again, at the cost of his own life.
23 September 1978: broadcast of fourth episode of The Ribos Operation. The Doctor is rescued by the shrivenzale, blows up the Graff, and converts the jethrik into the first segment of the Key to Time.
Apologies by the way for yesterday's entry, which I did not finish editing before it was posted.