i) births and deaths
6 April 1959: birth of Mark Strickson, who played the Fifth Doctor companion Turlough in 1983-4.
ii) broadcast anniversaries
6 April 1968: broadcast of fourth episode of Fury from the Deep. Van Lutyens, and then the Doctor and Jamie, descend to the base of the impeller shaft and find the Weed Creature gathering in strength.
6 April 1974: broadcast of third episode of The Monster of Peladon. Sarah raises Queen Thalira's consciousness, and the Ice Warriors arrive.
6 April 2013: broadcast of The Rings of Akhaten. Clara Oswald wants to see something awesome, so the Eleventh Doctor whisks her off to the inhabited rings of the planet Akhaten, where the Festival of Offerings is in full swing. Clara meets the young Queen of Years as the pilgrims and natives ready for the ceremony. But something is stirring in the pyramid, and a sacrifice will be demanded.