1 June 1947: birth of Jonathan Pryce, who played the Master in The Curse of Fatal Death (1999).
1 June 1991: death of Milton Subotsky, who produced and wrote Dr. Who and the Daleks (1965) and Daleks - Invasion Earth 2150 AD (1966), the two cinema films starring Peter Cushing as Doctor Who.
1 June 2005: death of Geoffey Toone, who played Temmosus in Dr. Who and the Daleks (1965) and Hepesh in The Curse of Peladon (1972).
ii) broadcast anniversaries
1 June 1968: broadcast of sixth episode of The Wheel In Space, ending Season 4 of Old Who. The Doctor manages to destroy the Cybermen with the X-ray laser; and Zoe stows away on the Tardis.
1 June 1974: broadcast of fifth part of Planet of the Spiders. The Doctor confronts the Great One, and escapes to Earth with Sarah; but she is under the spiders' control.
iii) date specified in canon
1 June 1977: Queen Elizabeth II's Silver Jubilee, as celebrated in Mawdryn Undead (1983).