Now, really back to the original topic and to the beginnings. I’m afraid I have to exercise some pre-production speculation first, but would appreciate corrections from Trek production history specialists where applicable.
What came first? The 5-year-mission or the stardate concept?
Roddenberry said he didn’t want to use real dates to fix a certain point in time in the future but I think that’s not the whole truth. Before TMP and Decker’s “300 years ago” remark regarding Voyager 6 (hasn’t been launched yet, has it?

), TOS was repeatedly (and consistently I should add) set in the future “200 years” from the 1960’s, so the future century had been fixed.
Of course, there is another 5-year-mission (“continuing the work of my late husband”, according to Majel-Barrett Roddenberry), namely that of
Babylon 5.
Joe Michael Straczynski (JMS) had wrote himself into a hole from the start. It’s a 5-year-story he wanted to tell in 5 seasons and that almost didn’t happen (I think it actually became a 6-year-story after the original planned Season Five became part of Season Four).
Had Roddenberry provided the year 2166 for the first episode, his 5-year-mission would have ended in 2171.
Of course, he didn’t know how many seasons of Star Trek he’d be able to produce, so rather than limiting his possibilities he came up with the stardates, a time measurement whose scheme was only “known” to the Star Trek creator.
The original episodes were broadcasted out of production order (and out of the modest chronological stardate order these had). Asked about the discrepancies Roddenberry referred to the manipulation of space and time (by the warp engines) and concluded
“I’d just as soon forget the whole thing before I’m asked any further questions about it.” (The Making of Star Trek)
Perfectly understandable!
The creator didn’t know yet and the correct answer would have probably been “I’ll tell you when I’m finished telling my 5-year-story (because only then can I calculate the elapsed time between the first and last stardate mentioned and give you an approximation)”.
But at the time of the Whitfield interview Gene Roddenberry couldn’t foresee, yet, when he was actually and terminally done telling his story.
But although understandable from a practical production point of view, the inevitable negative side effect was an apparent inconsistency of stardates. According to the writer’s guide suggestion 1 stardate digit equaled one day but this would have put the 5-year-mission at an end by the conclusion of Season One (were they
that pessimistic?).
Did they change the scheming during TOS? For the fun of it I did a little math. In the first season, the average space allocated to each single episode would have been 72.6 digits, 86 digits for Season Two and 65.5 digits for Season Three.
Apparently and encouraged by the success of Season One they allocated wider timeframes for the second season but when they knew they had only one third season left to go, they rather drastically reduced this timeframe as if to meet a deadline, perhaps Stardate 6000.0 (because the stardate of the last episode produced
and broadcasted was “5928.5”).
But when would have been a good time for Gene Roddenberry to state we had seen everything of the 5-year-mission (and to do “his” stardate math)?
I think it’s fair to say that by the time of the motion picture (TMP) it was clear and final that the 5-year-mission had become a thing of the past.
TMP is the next item I’m going to address, stay tuned.
Bob