Oh, hang on...
i) broadcast anniversaries
23 November 1963: broadcast of "An Unearthly Child", first episode of the story we now cal An Unearthly Child, and the first ever episode of Doctor Who. Teachers Ian and Barbara follow their mysterious pupil home to a police box, which contains the time and space ship - the TARDIS - of the enigmatic Doctor. It transports them - but to where?
23 November 1968: broadcast of fourth episode of The Invasion. The Doctor and UNIT rescue Isobel and Zoe; and Jamie and the Dioctor witness a Cyberman emerging from its cocoon.
23 November 1983: first broadcast of The Five Doctors, in the USA. (British audiences see it two days later.) The First, Second, Third and Fifth Doctor are united on Gallifrey to play the Game of Rassilon.
23 November 1987: broadcast of first episode of Dragonfire, introducing Ace. The Doctor and Mel land on Iceworld where they encounter their old friend Sabalon Glitz, and a stroppy waitress.
23 November 1988: broadcast of first episode of Silver Nemesis. The Doctor and Ace go back and forth between Windsor Castle in 1988 and 1638, dealing with the Nemesis meteor and Lady Peinforte's status; then the Cybermen arrive.
23 November 1989: Silvester McCoy records the voiceover at the end of episode three of Survival, the very last words of Old Who.
23 November 2009: release of third episode of Dreamland.
ii) births and deaths
23 November 1914: birth of Roger Avon, who played Saphadin in The Crusade (1965), Daxtar in The Daleks' Master Plan (1965) and Wells in Daleks - Invasion Earth 2150 AD (1966)
23 November 1963: birth of Joe Ahearne, who directed Dalek, Father's Day, Boom Town and Bad Wolf/The Parting of the Ways (all 2005).
23 November 1990: death of Mostyn Evans, who played Dai Evans in The Green Death (1973) and the High Priest in Death to the Daleks (1974).
23 November 2003: death of Bill Strutton, writer of The Web Planet (1965) and the novelisation Doctor Who and the Zarbi.
iii) dates specified in canon
23 November 1638: The Doctor launches the Nemesis status into space. (Silver Nemesis, 1988)
23 November 1863: death of Victoria Waterfield's mother (according to Marc Platt's 1996 novel Downtime).
23 November 1997: Re-coronation of Elizabeth II, attended by the Fourth Doctor, Romana and K9 in Lance Parkin's 1997 novel The Dying Days.