15 May 1925: birth of Roy Stewart, who played Toberman in Tomb of the Cybermen (1967) and Tony in Terror of the Autons (1970).
15 May 1937: birth of Darrol Blake, director of The Stones of Blood (1979)
15 May 1990: death of Peter Grimwade, director of Full Circle (1980), Logopolis (1981), Kinda (1982) and Earthshock (1982) and writer of Time-Flight (1982), Mawdryn Undead (1983) and Planet of Fire (1984).
ii) broadcast anniversaries
15 May 1965: broadcast of "The Final Phase", fourth episode of the story we now call The Space Museum. The Xerons revolt and kill the Moroks, allowing the Tardis team to escape.
15 May 1971: broadcast of sixth episode of Colony in Space. The Guardian destroys the ancient weapon, and himself; the IMC surrender to the colonists; the Master escapes, and the Doctor and Jo return home.
15 May 2010: broadcast of Amy's Choice. Amy is forced to choose between different versions of reality by the Dream Lord.
iii) dates specified in canon
15 May 2008: death of Donna Noble's father, Geoff.
15-18 May 2009: events of Gary Russell's 2009 novel, Beautiful Chaos.