22 March 1950: birth of Mary Tamm, who played the first Romana in 1978-79.
ii) broadcast anniversaries
22 March 1969: broadcast of third episode of The Space Pirates. Clancey and the Tardis crew evade General Hermack and arrive at the pirate base on Madeleine's plant.
22 March 1975: broadcast of third episode of Genesis of the Daleks. Sarah has failed to escape from the Thal dome, but Harry and the Doctor arrive to rescue her - and the Doctor is electrocuted.
22 March 1983: broadcast of first episode of Time-Flight. A Concorde is kidnapped and the Doctor, Tegan and Nyssa investigate.
22 March 1985: broadcast of first episode of The Twin Dilemma, first full episode for Colin Baker as the Sixth Doctor. The new Doctor is behaving strangely; meanwhile the Sylvest twins have been kidnapped.
22 March 2003: webcast of "The Child, Part 3", the seventh episode of Death Comes to Time.
22 March 2010: broadcast of Oroborus, eleventh episode of the Australian K9 series. K9 notices a change in behaviour in his friends and discovers time itself is being disrupted. Small chunks of time are being eaten away. A Time Snake has invaded the mansion and Starkey makes a discovery about his own parents that means he alone can face the Oroborus. He offers himself as a meal to defeat the creature.
iii) date specified in-universe:
22 March 2011: setting of most of the Torchwood: Children of Earth episode Rendition. Jack and Gwen are unwillingly transported to America, and Jack survives poisoning.