The Enfolded Time (short story)

 was a story which was original to the anthology The HAVOC Files. It asserted that due to the Doctor's frequent visits to the 1970s and 1980s in his faulty TARDIS, the two decades were merged into one and 20 years of Earth history took place over the course of 10 — thus providing an in-universe justification for the UNIT dating controversy.

Summary
After a New Year's gathering in his home on the grounds of Brendon School, Alistair Lethbridge-Stewart is visited by a young man called Albert Wilson. Just as the two men are about to meet, Lethbridge-Stewart finds himself in an odd place where he encounters various versions of him, from the last twenty years. Including Colonel Lethbridge-Stewart of the Fifth Operational Corps and Brigadier Lethbridge-Stewart of UNIT. They attempt to explain to him what is happening, but he finds it hard to follow.

Eventually he meets the Accord, a transdimensional being who is trying to repair the damage caused to Earth, to strengthen it before a forthcoming war that is going to spread all across time and space. The Accord explains that, due to the Doctor's regular visits to Earth from 1969 to 1989 in his damaged TARDIS, the timeline of Earth was disrupted, enfolding time in on itself so that twenty years occurred over a ten-year period. Nobody on Earth was aware of the problem, as they were an intricate part of it. The Accord explains that once Lethbridge-Stewart is returned home, an awareness will occur across the globe. For a brief moment everybody will recognise the discontinuities of the last twenty years.

Lethbridge-Stewart is returned to Earth, and for a short time forgets where he has been. He meets Albert Wilson and learns that Albert is his son, a result of his tryst with Doris back in Brighton in 1968. It is only recently that Albert learned of Lethbridge-Stewart, and now that he has his own child on the way, Albert wishes Lethbridge-Stewart to be part of their lives.

A phone call from the United Nations reminds Lethbridge-Stewart of his recent trip to the domain of the Accord. Discrepancies have been discovered in various UNIT reports. Lethbridge-Stewart arranges a meeting to discuss the development of new dating protocols.

Characters

 * Brigadier Alistair Lethbridge-Stewart
 * Major William Bishop
 * Albert Wilson
 * The Accord

Worldbuilding

 * The story says Lethbridge-Stewart left the UN in 1976, the year TV: The Seeds of Doom came out: the last UNIT story to say he was still in charge.
 * One version of Lethbridge-Stewart dates TV: The Web of Fear to 1975. Edward Travers said in that story that he'd met the Doctor in Tibet forty years ago, in a story TV: The Abominable Snowmen generally dated to 1935.

Continuity

 * One of the Lethbridge-Stewarts refers to coming from "second meeting about my retirement" in Geneva and missing the events of The Seeds of Doom, implicitly meaning his absence in TV: The Android Invasion was due to the first meeting.
 * The Eighth Doctor had claimed responsibility to the UNIT dating controversy, blaming it on temporal slippage. (PROSE: Interference: The Hour of the Geek)
 * The Gwanzulum once tried to infiltrate the Home-Army Fifth Operational Corps. (COMIC: Planet of the Dead)
 * In 1983, Alistair met his younger self from 1977 and had his memories of encountering aliens restored. (TV: Mawdryn Undead)
 * The Brigadiers refer to his first kiss being with Jemima Fleming, but due to the messy circumstances of it (PROSE: In His Kiss) they prefer to believe it was with Imelda Clarke, when they lived in Coleshill.
 * Due to the enfolded time, Alistair and the Brigadier remember the London Event happening in February 1969, while the Colonel remembers it from 1975; the Brigadier is retiring in 1981 while Alistair did it in 1976; Alistair mentions "all that business with the dinosaurs in 1974", while the Brigadier remembers it in 1979. (TV: Invasion of the Dinosaurs)
 * Albert mentions that George Wilson had an older sister named Barbara who died in a car accident in 1951. (TV: The Temptation of Sarah Jane Smith)
 * A dating protocol is established for the enfolded time. (TV: The Day of the Doctor)