For example, in "The Web of Fear" (Season 5), the action takes place in 1975, seven years in the future.
Originally, I had both "The Web of Fear" and "The Invasion" placed in 1968, and the events from "Spearhead from Space" to "The Hand of Fear" running from 1970 to 1976.
The dating for these stories now runs as follows (many thanks to Donald Gillikin for suggesting this solution and most of these dates): have that problem with Sarah supposedly being from 1980.
This is a reference to what is known within fan circles as the ‘UNIT dating controversy’, which stems from the fact it’s impossible to reconcile the UNIT stories into one coherent timeline.
The Doctor’s first meeting with Brigadier Lethbridge-Stewart, in 1968’s taking place four years later.
For at least the third time this series, one or all of the characters you care about on this show are dead.