18 April 1928: birth of David Whitaker, the first script editor of Doctor Who (from An Unearthly Child to The Dalek Invasion of Earth) and writer of The Rescue (1964), The Crusade (1965), The Power of the Daleks (1966), The Evil of the Daleks (1966-67), The Enemy of the World (1967-68), The Wheel in Space (1968) and The Ambassadors of Death (1970); also of the 1965 stage play, The Curse of the Daleks, and of two of the first three novelisations, Doctor Who in an Exciting Adventure with the Daleks (1964) and Doctor Who and the Crusaders (1965).
18 April 1929: birth of Peter Jeffrey, who played the Pilot in The Macra Terror (1967) and Count Grendel in The Androids of Tara (1978).
18 April 1930: birth of Angus Lennie, who played Storr in The Ice Warriors (1967) and Angus MacRanald in Terror of the Zygons (1975).
18 April 1956: birth of Eric Roberts, who played the Master in The TV Movie (1996).
18 April 1971: birth of David McDonald, better known as David Tennant, who played the Tenth Doctor from 2005 to 2010.
ii) broadcast anniversaries
18 April 1964: broadcast of "The Temple of Evil", second episode of the story we now call The Keys of Marinus. Barbara defeats the evil bottled brains.
18 April 1970: broadcast of fifth episode of The Ambassadors of Death. The Doctor blasts off to investigate the Mars probe for himself.
18 April 2010: broadcast of Victory of the Daleks. WOULD YOU LIKE A CUP OF TEA?
iii) date specified in canon
18 April 1906: the San Francisco earthquake, as featured in Andy Lane's extraordinary 1994 novel, All-consuming Fire.
An awful lot of birthdays today, David Tennant being the last but not the least. If you want your child to be involved with Doctor Who, perhaps you should plan a hot date with your partner around 18 July...