28 March 1924: birth of Robert James, who played Lesterson in The Power of the Daleks (1966) and the High Priest in The Masque of Mandragora (1976).
28 March 1983: birth of Gareth David-Lloyd, who played Ianto Jones in the first three series of Torchwood (2006-09).
28 March 1987: death of Patrick Troughton, three days after his 67th birthday, while attending a convention in Georgia.
ii) broadcast anniversaries
28 March 1964: broadcast of "Mighty Kublai Khan", sixth episode of the story we now call Marco Polo. Ping-Cho flees, but the Doctor and the Khan bond.
28 March 1970: broadcast of second episode of The Ambassadors of Death. The returned Mars probe is captured by Carrington's men, and retrieved by the Doctor. But who or what, if anything, is inside?
iii) dates specified in canon
28 March 1963: murder of Lizzie Lewis by Ed Morgan, as later transpires in the Torchwood story Ghost Machine (2006).