Looking at my timeline, which I arrived at back in the "Lit-verse Based TOS Chronology" thread, I ended up being somewhat vague about the specifics of when The Search for Spock takes place, but overall I placed a 12 to 13 month gap between TWoK and TVH. This whole era, though, is one that I have to say that, in my personal continuity, something LIKE those issues occurred, but definitely not the exact details as they are presented in those comics. I'm not even sure I can accept the overall idea that Kirk commanded the Excelsior, for instance, and jettisoning that idea would be a pretty dramatic change to those stories.
Sounds like we have approximately the same span, then, details aside. But what do you imagine filling those months, if
not the events of the comics series? AFAIK there's not a single novel set in that period, for instance (which is understandable, since a face-value viewing of the movies doesn't necessarily make it evident that any period of time between them even exists).
No, it doesn't have to, because this isn't a historical document, it's just a made-up story. It's all just pretend...
Of course, I'm sure we all understand that. But if we're going to try to derive non-obvious information
about that story (or metanarrative of related stories), we need to have some reasonably consistent rules of evidence. (Much like the efforts put into determining the chronology of the Sherlock Holmes stories, for instance... saying "it's all pretend" is much less satisfying than sussing out clues from the information Watson provided, especially since Watson himself admits he's an unreliable narrator at times.) Otherwise, saying "it's all pretend" means all bets are off, and there's no way to assess the plausibility of
any particular chronological arrangement.
So, in that sense, matching testimony from two characters is firmer evidence than a statement from one character alone. Likewise, by the very psychology of round numbers you described, if characters are being imprecise, it's fair to assume that they might round 14 or 16 years to 15, but they'd be more likely to round 18 up to 20.
...and if we're trying to pretend that two things fit together sensibly when they really don't, then we can just gloss over the bits that don't fit.
Which brings us to the supplementary point I made: there really isn't anything about putting STII fifteen years after "Space Seed" that
doesn't fit the rest of the canon. The only thing it doesn't fit with, actually, is the Okudachron (and later licensed works that take their dates from the Okudachron).
(There are other bits of canon that don't quite fit the Okudachron. In the 24th century era, for instance, the internal references in TNG's "Data's Day" and DS9's "Emissary" and "Second Sight" and VOY's "11:59" and "Homestead," among others, don't remotely correspond to the way the Okudachron bases dates on stardates. And in all of those cases, as well, I follow the on-screen evidence to the greatest extent possible, and treat the Okudachron as apocryphal.)
Again, it's a matter of having the freedom to interpret things. ... None of this is absolute, because it's all just stories. If they can make stuff up, so can we.
Sure. And sometimes it's necessary. But if it's
not necessary, I try to avoid it. Because the more we do so, the harder it is to argue for our conclusions as anything other than personal whim.
After all, the only character who mentions "20 years" in TFF is Caithlin Dar, a Romulan. So why in the world would she use Earth years?
True, but she's talking with the Federation and Klingon representatives, not with other Romulans. Presumably, then, universal translators are at work. The usual assumption in Trek is that when we hear something translated into "Federation Standard" (
aka modern English), the units and such correspond to ordinary usage in that language. To say that on-screen references to years are
not routinely meant to be understood as Earth years would reduce all kinds of chronological references to complete inscrutability and ambiguity... unless the argument is that
only this one uses non-standard years, but that's a case of special pleading, and would require some justification for treating it differently from other references.
At any rate, as I mentioned earlier, it doesn't actually make a difference where STV is concerned. Even if it's 19 years or 21 years since Nimbus III was founded (and even if that founding wasn't in 2267), there's
still an indeterminate gap between it and the previous movie... a gap that accommodates putting STII-IV where (IMHO) they belong, in 2283-84.
The next specific chronological references we get are in STVI, where we learn that Sulu has been captain of the
Excelsior for three years and McCoy has been CMO of the
Enterprise for 27 years, which allow us to backdate a
terminus ante quem for STV (basically, not later than 2289). Long story short, that movie (if one treats it as canonical at all, but I'm not going to get into that debate!) falls somewhere in the range of '86 to '89. All else equal, then, I find it easiest to take the on-screen reference at face value, assume that Nimbus III was founded within a year or so of the Organian incident, and put the movie in '87.
Except for the TWOK-TFF dates. Those make no damn sense. Even if you assume the "20 years after 'Balance of Terror'/'Errand of Mercy'" thing as the excuse for TFF, how can there be a year between TSFS and TVH when it was explicitly stated to be three months? And if they were willing to round up 15 years to 18, why not just round 20 years down to 17?
Okay, I wholeheartedly agree that the Okudas really didn't make any sense of that. But at least (unless I'm recalling incorrectly; it's been a while since I read it!) they owned up that they
were departing from the on-screen evidence in that case, and didn't try to pretend otherwise.
My inference at the time (and it was just that, so I may be wrong, and I'd be curious if anyone has better information!) is that they were treating STV as if there
weren't a significant gap between it and the previous film. (It's possible to view it as the Ent-A's first mission, after all, especially as Scotty does use the term "shakedown"; I prefer to interpret that as the ship having just had a minor refit, which also handily explains why its bridge looks different vs. the end of STIV.) Thus they fudged things a bit, taking a set of four movies that should logically bracket a four- or five-year period but didn't seem to, and instead spreading them out just a
little over only a couple of years. Why they then chose to anchor that spread with the far less popular film (STV) rather than the far more popular one (STII), I can't imagine. Maybe they flipped a coin, for all I know.
They did make some peculiar judgment calls at times. Even given that they chose to disregard TAS, for instance, if they'd simply treated TOS as the
first three years of the FYM rather than the
last three, it would have left more than enough time for those who preferred to accommodate TAS. Instead, they made that harder instead of easier (and then got trumped later by the canonical info from VOY's "Q2" anyway).