Quoting from Roddenberry in
The Making of Star Trek: Star dates were invented to get around the problem of episodes being shown "out of order" and had the side benefit of obscuring the relativity problem:
Unfortunately, however, the episodes are not aired in the same order in which we filmed them. So we began to get complaints from the viewers, asking, "How come one week the star date is 2891, the next week it's 2337, and then the week after it's 3414?"
In answering these questions, I came up with the statement that "this time system adjusts for shifts in relative time which occur due to the vessel's speed and space warp capability. It has little relationship to Earth's time as we know it. One hour aboard the U.S.S. Enterprise at different times may equal as little as three Earth hours. The star dates specified in the log entry must be computed against the speed of the vessel, the space warp, and its position within our galaxy, in order to give a meaningful reading." Therefore star date would be one thing at one point in the galaxy and something else again at another point in the galaxy.
I'm not quite sure what I meant by that explanation, but a lot of people have indicated it makes sense. If so, I've been lucky again, and I'd just as soon forget the whole thing before I'm asked any further questions about it.
Thinking of the passage of time in terms of "years" only became an issue starting with
TMP, because that's when the Enterprise first visited present-day Earth (other than between episodes). Yes, of course "years ago" appeared in dialogue in occasional episodes, but that's not the same thing as counting from a baseline number; also it would have been confusing to speak in terms of "star date units ago" and not worth the trouble to do so.
All I'm saying is that any effort to make a coherent chronology is futile. (Especially any effort to prove that there was a time lapse, or continuity of any sort, between
TMP and
TWoK. Other than Vonda McIntyre's novelization of
TWoK -- which occasionally throws in a reference to Deltans, etc., but also has Spock's coffin burning up while entering the Genesis planet's atmosphere -- what non-retroactive, circa 1982, indication exists that
TWoK is a sequel to
TMP?) Just enjoy what you can of the various episodes and movies, and if at one time in your life you cared enough to have purchased the
Star Trek Chronology and now you don't care any more -- or vice versa -- that's OK too.
(
Making of Star Trek excerpt is from Memory Alpha, which I trust to have gotten it right; I bought my own copy of the book in 1969, but at this moment I'm too lazy to look for it and verify the quote.)
