Star Trek 2 was in 2283 for Kirk's 50th birthday
Whatever year ST2 was, the one thing we can be absolutely certain of is that it wasn't in 2283. This because Kirk reads out this year on his gift bottle of ale, and the year is indicated to be significant somehow, presumably an alarming number of years in the past for a bottle of ale. If the year on the bottle were the current year, then there's no way it could hold such significance.
We're probably dealing with Kirk's 51st or 52nd birthday, then - all the more tragic because he's now noticeably past yet another important watershed, and
still stuck in the no-future desk job. If 50 was bad, then 52 is worse.
I think the comics did a fantastic job of doing their own thing, while reconciling events with the ongoing (at the time) movie series.
Yup - they did a great job in making themselves suitably unobtrusive and easy to ignore.
Similarly, the
A Time to... novels inserted a range of E-E adventures between ST:INS and ST:NEM to indicate how Picard would fall from grace and get stuck with the starship rather than proceed to meatier assignments. Which was another exercise in futility, because ST:INS already featured him falling from grace by scorning Starfleet and the Federation and starting an armed rampage.
The solid fixpoints in the TOS movies are few and far in between.
ST2: After 2283, about 15 years after "Space Seed" which must be after 2266 but before 2270
ST3: no solid fixpoints (unless we count the "Enterprise is over 20 years old" bit, which might suggest 20 years have passed since ST:TMP which was no earlier than 2273)
ST4: At least three months after ST3
ST5: A few weeks after the ending of ST4, which may be several months or even years after the beginning of ST4.
ST6: "Approximately" 80 years before VOY "Flashback"
ST:GEN teaser: 78 years before the TNG parts, so fixed at 2293
A ballpark of 2284-86 seems to work best for the ST2-4 run, then... Although 2287 would still be (barely) tolerable for events taking place about 15 years (that is, anything up to 17½ years) after "Space Seed".
Kirk and co are ready for retirement, so one would have thought he had to be at least 60.
FWIW, the animated episode "The Counter-Clock Incident" sets Starfleet retirement age for human officers at 75, and suggested it might be revised upward soon enough. And in TNG "Too Short a Season", a man in his eighties believes he would still be in active service as a starship commander if not for his debilitating disease.
Timo Saloniemi