Pretty consistent, although not quite good enough for TMP dating. The first 5 year mission ends in 2270. We can assume that Kirk's promotion didn't take place immediately after the 5-year mission (e.g. perhaps Enterprise had a couple of local diplomatic assignments) so that not logging a single star hour for 2.5 years could mean that more than 2.5 years had still passed. However, we don't have quite enough time to fit in a second (non-canon?) 5-year mission plus a period of time for the crew to settle into their training assignment. An extra year in there would have been a perfect fit!
The dates allow a second five-year mission, but before TMP, rather than after. If the
Enterprise returned in 2270, then left on a second five year mission, something less than three years (assuming a brief refit between missions) would remain between that mission and TMP, allowing Kirk's 2.5 years without a "star hour". Six years between TMP and TWOK would also allow him a brief (perhaps years-long) return to the stars before settling down at Starfleet Academy.
How're you getting these figures?
dJE
I began with the first stardate from
The Wrath of Khan. It falls on Kirk's birthday (22 March), in 2283 or later (McCoy's Romulan ale), and is roughly fifteen years after
Space Seed. 22 March, 2283 is not quite sixteen years after
Space Seed, so I presumed that date for stardate 8130.3.
Next, I took the stardate for the Enterprise-B's commissioning, 9715.5. According to the movie, this takes place 78 years before the TNG portion of the film; for simplicity's sake, I took it to be exactly 78 years earlier (this has some effect on exact dates, but less than one might think).
I then divided the difference between the stardates by the difference (in days) between the dates. I took the result as representing the number of stardate units per day (roughly 0.4; the actual figure is much less pretty) in the movie era. Using that number, I calculated possible dates of the remaining movies from their stardates.