1 February 1948: birth of Elisabeth Sladen, who plays Sarah Jane Smith (companion to Third and Fourth Doctors, 1973-76; various appearances since then culminating in her own series since 2007). Happy Birthday, Lis!
ii) broadcast anniversaries
1 February 1964: broadcast of "The Rescue", seventh episode of the story we now call The Daleks (and nothing to do with the story we now call The Rescue). Ian, Barbara and the Thals destroy the Daleks' power source, defeating them, and rescue the Doctor and Susan.
1 February 1969: broadcast of second episode of The Seeds of Death. The Doctor, Zoe and Jamie head for the Moon by rocket; Miss Kelly T-Mats to the Moon and repairs the equipment but is captured by the Ice Warriors.
1 February 1975: broadcast of second episode of The Ark in Space. The humans on the Ark start to wake up; but Noah, their leader, has been infected by the Wirrn.
1 February 1982: broadcast of first episode of Kinda. The Doctor and Adric are captured by the Earth expedition on Deva Loka; Tegan's mind is ensnared by the wind chimes.
1 February 1983: broadcast of first epsiode of Mawdryn Undead; first appearance of Mark Strickson as Turlough, and return of Nicholas Courtney as the Brigadier after seven years. Turlough agrees to kill the Doctor at the request of the Black Guardian; meanwhile the Doctor loses Nyssa and Tegan in a timewarp.
iii) date specified in canon
1 February 1967: birth of Jackie Tyler, née Prentice. (At least of the parallel version from Pete's World.)