UNIT Dating

his article is about the controversy over when the UNIT stories are set. The aim of this article is not argue for one position or to come up with specific dates for stories, but to outline the arguments used for different dating systems.

What is the UNIT Era?

"The UNIT era" refers to the time period in which the third Doctor was exiled to Earth (Seasons 7-9 of the Classic series). During this period, the Doctor teamed up with the United Nations Intelligence Taskforce (UNIT) to fight alien invasions. The term usually also covers The Invasion, where the second Doctor teamed up with UNIT (in their first appearance) as well as all stories where the third and fourth Doctors worked with UNIT after his exile was lifted (Seasons 11-13). Later stories featuring UNIT tend to be set a long time after these stories and are not considered part of the UNIT era.

1960s Dating

This theory, dating the UNIT era to in the mid-late 1960s, has very few, if any, proponents. However, there is some evidence that supports this view, and this evidence is sometimes brought up in debates.


The major piece of evidence for this theory comes from Carnival of Monsters (ep. 1), in Season 10, right after the Doctor's exile has been lifted. In this story Jo Grant claims that the year 1926 was 40 years ago, making the current year 1966. A small amount of the evidence cited below in favour of an early 1970s dating also supports this theory.


This line from Jo is literally the only evidence that points to a 1960s date, so we would have to discard all the other dating evidence for this theory to work. There is also a problem that is unique to this dating scheme. The Sarah Jane Adventures stories [sja]Whatever happened to Sarah Jane?[sja] and The Temptation of Sarah Jane Smith establish that Sarah was born in 1951 (the latter story specifying May). If her introduction in The Time Warrior (the first story of Season 11) is only a year after Jo's date, that means that she was only 16 when she pretended to be her aunt (who was a distinguished scientist).

Explaining away the evidence

The most common way to explain away this line is to point out that Jo is not considered to be particularly intelligent or educated. If she is as bad at maths as she is at science (She failed science O-Level according to Terror of the Autons), then it would be entirely in character for her to miscalculate how far in the past she is.

Early 1970s Dating

This theory is probably the most widely held by today's fans. Proponents include Paul Cornell, Keith Topping and Martin Day in The Discontinuity Guide, John Preddle in Timelink, Tat Wood and Lawrence Miles in About Time, and Stephen Gray of this site. Chronologies vary in the details, but most of them place Season 7's Spearhead from Space in 1969 (or occasionally 1970) and work forwards from there.


The biggest single piece of evidence for an early 1970s date is fifth Doctor story Mawdryn Undead The story establishes that The Brigadier (one of the major characters in the UNIT Era) retired in 1976, before the story took place. The story is set in two time zones. The earliest of which is undeniably in 1977 (In addition to repeated dialogue, there are ''1977 - the Queen's Jubilee'' banners and T-Shirts all over the place.). There is supporting evidence given in the spin-off K9 and Company, This story is set in December 1981 (Sarah Jane Smith says so onscreen), and the impression is given that Sarah's travels with the Doctor (from Season 11 onwards) were some time ago. The format document for the series dates her travels with the Doctor as happening between 1973 and 1976, although these dates don't appear onscreen.

The rest of the televised evidence for this position comes from little background details. The clothes, haircuts, and cars all fit the year each story was made, except for The Invasion. The most obvious example of this is the use of pre-decimal currency in Doctor Who and the Silurians. There is also a reference to Mao Tse Tung being alive in The Mind of Evil (In the real world Mao died in 1976). Another notable example is that the tube map in The Web of Fear (Which happens only a few years before The Invasion) dates from before the Victoria line was opened in 1969. The final TV example that we will cite is that the Doctor's new car in Season 11's Invasion of the Dinosaurs is an M reg (1973), There are many other examples of such background details, these are merely the most prominent.

There are a substantial number of novels which explicitly follow this dating scheme. No Future is unambiguously set in 1976, shortly before the Brigadier's retirement. Who Killed Kennedy explicitly dates every televised UNIT story up to Season 9's Day of the Daleks in this period. Other novels that use these dates include The Left-Handed Hummingbird, The Eye of the Giant, [ma]The Scales of Injustice[/m] (Although the book offers a number of specific dates that contradict each other), The Devil Goblins from Neptune, Deep Blue, The Ghosts of N-Space (Some might want to give this novel/radio play extra weight due to it being written by Barry Letts, who was producer for the whole of the Third Doctor's run, and it having been aired as an audio play starring Jon Pertwee), and Genocide.


The main problem with this particular approach is that it ignores the evidence cited above and below for other dating schemes. There is also the problem that the stories often feature technology that is more advanced than was actually available in this period.

Explaining away the evidence

There are a number of approaches to getting around the Mawdryn Undead date:

  • To claim that the particular type of time travel within the story has somehow caused the dates to go weird.(Most notably David A McIntee suggested this theory in the foreword to Face of the Enemy)
  • To claim that the dating is correct, but that the Brigadier has been taken back in time by the manipulative seventh Doctor.
  • To dispute the dates given onscreen. This not only ignores all the actual evidence, but it either mucks up the six year gap between the timezones within the story, or changes the established dates for the non-UNIT story Planet of Fire (meaning that Turlough returns home to Trion whilst he is still an exile, or that Peri is from a period much later than is established).
  • Eric Saward, the script editor for this story, claimed that the dating in this story was "a mistake". Some fans take this off-screen evidence to be the final word, and ignore this dating.

The extensive dating in Who Killed Kennedy has been undermined by a brief comment in The Dying Days, which suggested that the dates had been altered by the government. Other dates from the novels have been explained away by declaring the novels to be "non-canonical" or suggesting that they are automatically overruled by the TV program.

Supporters of other theories usually explain away the background details by claiming that, as background details, they are as much part of continuity as bad special effects.

Late 1970s Dating

The most notable supporter of this date is Lance Parkin, who states it to be his personal preference in the Mad Norwegian editions of AHistory. Who author David A McIntee also holds this position, although none of his novels have explicitly used a late 70s date.


The core evidence for this theory is Sarah Jane Smith's claim to be from 1980 in Pyramids of Mars. This is taken to be either a reference to her first story (Season 11's The Time Warrior), or to the last time she was in her native era (Season 13's Terror of the Zygons).

Supporting evidence for this theory comes from various bits of technology and politics that doesn't fit with the reality of the early 1970s. Although the technology in the UNIT era isn't as far ahead of its time as in, for example, superhero comicbooks, it does feature a lot of technology that wasn't available in the real early 1970s. Politically, there's a Prime Minister called Jeremy in Season 10's The Green Death (This was intended as a reference to Liberal Party leader Jeremy Thorpe, who was never Prime Minister in the real world), and to an unnamed woman Prime Minister in Terror of the Zygons. These details are interpreted as indicating a near future setting, and the fact that some details are wrong is about as relevant as the fact that any story set in the future will get details wrong.

There is only one novel that explicitly uses a late 70s UNIT dating. Rags, set somewhere in the middle of the UNIT era, claims to be set in 1979, and heavily features Punk music, although a couple of lines in the novel suggest a slightly later setting.


The main problem with this approach is the evidence for other eras.

Explaining away the evidence

The political details are generally explained away as being a result of this being a parallel universe. At the time of writing (Summer 2019) there has yet to be a British Prime Minister called Jeremy.

The female PM is somewhat complicated. On the face of it this could be seen as an accurate prediction that Margaret Thatcher (leader of the opposition at the time of recording) becoming PM. In Season 12's The Ark in Space Harry Sullivan is surprised that a woman is "top of the totem pole" in the future, which has been suggested to mean that the 1979 General Election happens whilst he was away. However, since there was plenty of reason at that time to believe that Thatcher would win the next election, some people have suggested this interpretation doesn't work. Opponents of this theory suggest that the female PM is actually then-Labour MP Shirley Williams, in an alternative timeline. This theory, supported by novels like No Future and Interference have Williams (rather than James Callaghan) becoming PM when Harold Wilson resigns in 1976

The most difficult evidence to explain away is Sarah's 1980 line. The most common approach amongst early 1970s advocates is to claim that Sarah travelled for quite some time with the Doctor, and was adding this to the year she came from. One variation on this approach is that Sarah had a break from her travels with the Doctor, and spent this time in 1980. A few will claim that Sarah is merely rounding up, and I once came across somebody who claimed that it was her house number (though I doubt they were serious).

1980s Dating

Supporters of a 1980s dating are primarily those who grew up in the Pertwee era. The most notable reference work to adopt this theory is David Banks' book Cybermen, although it should be noted that the only UNIT story considered in the book is The Invasion, which is the story which provides most of the onscreen evidence for this theory.


The primary onscreen evidence for this theory comes from a trio of Second Doctor stories that established the setting for UNIT. The Abominable Snowmen, set well before the UNIT era, does not establish any dates. However, the character Professor Travers from that story later appears in The Web of Fear, where his daughter Anne Travers claims that the earlier story happened in 1935. In the same story, Professor Travers claims that this was "over 40 years ago". In The Invasion, the Brigadier says that The Web of Fear happened "nearly 4 years ago". Add these dates together, and you get a date for this story of approximately 1979.

Supporting evidence is found in Seventh Doctor story Battlefield. Onscreen, this (non-UNIT-era) story is said to have taken place "a few years" in Ace's future, making it the late 1980s, or early 1990s. However, the novels (particularly The Dying Days) state that this story happened in 1997, in line with the author's stated intent. Although this doesn't directly affect dating the UNIT era, Sergeant Zbrigniev claims to have served in UNIT whilst the Doctor was there, and to have first hand experience of two of the Doctor's regenerations. Assuming that he doesn't mean that he witnessed two regenerations happen (which would be a continuity error, or mean that he saw regenerations of future incarnations of the Doctor), that means he was present for most of the UNIT era, or had an unrecorded adventure with some other incarnation of the Doctor. And unless he's a lot older than he looks, that rules out an early 1970s dating.

However, the main argument used by many 1980s supporters is authorial intent. Derek Sherwin, the producer who introduced UNIT, claimed that the UNIT stories were set in the near future. The Radio Times, the BBC's official listings magazine, often suggested a 1980s setting in its write-ups for the UNIT stories. And in 1969 Jon Pertwee claimed that his Doctor would be on Earth in the 1980s in an interview for the Daily Mail'. Eric Saward, the script editor for Mawdryn Undead claimed that the 1977 date for that story was a "mistake".

There are also the political and technological arguments raised in favour of a late 1970s setting. The technology argument is more compelling as an argument for the 1980s. For example, in the early 1970s NASA was planning a Mars landing for the early 1980s. The politics argument is probably weaker. Jeremy Thorpe was long gone from politics by the 1980s, leaving no candidate for a PM called Jeremy, as in The Green Death Proponents claim that this doesn't matter, as predictions not coming true does not mean that the story should not be considered a "near future" setting. After all, despite what The Tenth Planet shows, we didn't actually discover Mondas in 1986. On the other side of the politics argument, the idea of a more powerful United Nations (as seen by the existence of UNIT and its powers) and the Cold War being over (as in, for example, Robot) fits the 1980s a bit better than any other dating scheme.

As far as novels go, Millennial Rites and [pda[Heart of TARDIS[/pda] are the only ones to explicitly adopt this dating scheme.


This theory has the same problems as the late 1970s theory.

Explaining away the evidence

The politics and technology arguments are answered by early 1970s advocates in the same way as for the late 1970s version of the same arguments - this is a parallel universe whose politics don't match ours (e.g. there was never a Prime Minister called Jeremy), and whose technology is likely to be in advance of ours (thanks to all those alien invasions). The authorial intent argument is usually dismissed by pointing out that it's what's on screen (or in print or audio) that actually matters when interpreting a work of fiction.

The most common way to get around the Invasion/Web of Fear dating is to claim that Professor Travers is beginning to go senile. There is some evidence within The Web of Fear that he is forgetful and also some evidence that his mind is still quite sharp. Some commentators claim that this contrast is quite common in senility. Lawrence Miles and Tat Wood have argued that the Web of Fear date isn't given by Anne Travers but given by Victoria (who may not have known what year it was) and merely not contradicted by Anne, and that the forgetful Travers isn't forgetting the date, but merely making a very vague estimate, or having a slip of the tongue.(See About Time Volume 2 page 168). It has also been pointed out that the Web of Fear/Invasion date is the least clear of all the dates given onscreen.

The argument from Battlefield is rarely addressed.

However, there have been counter-arguments to the two novels favouring this date. The dates from Millennial Rites are primarily given as the length of the career of Anne Travers after The Web of Fear. Early 70s chronologies have suggested that the civil service job she is stepping down from in the novel is something she didn't acquire until well after The Web of Fear. This leaves one notable problem - as it is implied that the Inferno Project seen in Season 7's Inferno was something that Anne used her position to back. One suggested way around this problem is to suggest that this was something she did earlier in her career.

The dating in Heart of TARDIS is somewhat more explicit in placing UNIT in the 1980s. Early 70s advocates, however, point out that the story cannot decide whether it is set before or after Season 12's Robot in the UNIT timeline. Benton is still a Sergeant, which means that it must be before, and Yates is still in UNIT, despite leaving after Season 11's Invasion of the Dinosaurs<. However, UNIT troopers all recognise the fourth Doctor as their scientific advisor, so it must be after Robot. It is argued that this means that the story's dating is unreliable, or that it means that it must take place after the UNIT era, with the Brigadier, Benton, and Yates having temporarily returned to UNIT.

The changing timeline theory

A couple of novels imply that there have been changes to the timeline that allow the different dating systems to all be correct. Late 70s/early 80s advocate Lance Parkin has pointed to a changed timeline in No Future as one example (amongst several) of this, although he fails to explain why the early introduction of CDs would change the dates. Parkin also suggests that his own book The Dying Days was an explanation, although this just gives an excuse for ignoring any inconvenient dates given in Who Killed Kennedy.

There have also been a number of throwaway lines throughout the new series which talk about the UNIT era being "the 70s, or was it the 80s?" These are pretty weak evidence that the timeline has been changed, and the authors clearly intended these lines to be jokes about the whole debate.

One of the most popular versions of this theory is that the Time War is responsible for the discrepancy between dates given for the UNIT era. These claims have no explicit backing within the fiction, but are part of a trend in which many fans have used the time war as a quick, easy, and (arguably) lazy, way to explain away every continuity problem at once.

Fudging It

There are a number of fudge theories floating around that attempt to date the UNIT era without explicitly endorsing any of the theories.

  • Jean Marc L'Officier's Terrestrial Index dated the UNIT stories to the year after their release, trying to reconcile the onscreen evidence for an early 70s date with the production team intention that the stories were set in the near future. As a result, this book ignored most of the actual evidence.
  • The Virgin edition of Lance Parkin's A History of the Universe set the UNIT stories in an unspecified 1970s, The stories were placed in the chronology in a way that suggested an early 1970s dating, presumably to fit with Virgin's editorial policy rather than the author's personal preference (which is for a later dating scheme).
  • The Mad Norwegian editions of Lance Parkin's AHistory go one step further, and remove the UNIT stories from the rest of the chronology. Stories relating to UNIT are dated in the format of "UNIT Year 1" or suchlike. This book offers the suggestion that The Invasion and Spearhead from Space happened in either 1969, 1974, or 1979, and then dates the UNIT stories relative to those stories. The book states the author's personal preference for a 1974 start date. This schema doesn't offer a start date for a 1960s dating scheme. In Parkin's summary of the debate, he appears to be unaware that Carnival of Monsters offers a date in this range.

Our Take

Since this site uses in-universe evidence wherever possible, we favour an early 70s dating scheme, because that is where the majority of in-universe evidence points. However, in future, we may change our History of the Whoniverse section to allow users to pick their UNIT dating scheme, though unless the weight of evidence changes the early-70s scheme will remain the default view.

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