1958

The Doctor visits Professor Chronotis at St. Cedd's College, Cambridge. Accounts exist for both the Doctor's fourth and eighth incarnations having this encounter. (DW: Shada; WC: Shada)
The BBC television series Nightshade starring Edmund Trevithick as the title character comes to an end after five years. It is rebroadcast on BBC2 in 1968 (NA: Nightshade)
The Doctor travels to Dry Springs, and later to Area 51, where he helps ward off an invasion of Earth by the Viperox, along the way meeting Cassie Rice, and Jimmy Stalkingwolf and arranging freedom for two of the gray aliens connected to the famous Roswell crash. The exact date is unknown, however the Doctor hears the song "All I Have to Do Is Dream" by the Everly Brothers playing on a jukebox, placing events no earlier than May, when the recording became a hit. (DW: Dreamland)