14 July 1943: birth of Christopher Priest, apart from Douglas Adams the only famous science fiction writer to write stories for Old Who. Both of his scripts were in the end rejected, in famously acrimonious circumstances.
14 July 2008: death of Margot van der Burgh, who plays the First Doctor's fiancee in The Aztecs (1964) and Nyssa's stepmother in The Keeper of Traken (1981).
ii) broadcast anniversaries
iii) dates specified in spinoff literature
14 July 1993: The Seventh Doctor meets up with Ace, now aged 37, in Sydney Australia. (In Kate Orman's novel Set Piece, which I have not read.)