... sequentially in Stardate order, the first stardate we're given is 1312 (Where No Man Has Gone Before), and the last is 5943 (All Our Yesterdays). So it appears we do
get to see the five year mission in TOS's three seasons... if we are to assume that 1000 stardate points roughly equal a year.
I've never noticed that before.
Strange that it never occured to me to really look at the Stardates in any great detail.
Also, Catspaw (SD: 3018) evidently takes place before Space Seed (SD: 3141), meaning that the oft quoted 'continuity error' of Chekov not being on the Enterprise when Khan first visited her must not be true. Chekov is seen on the bridge on the earlier Stardate, ergo he was obviously there (off-screen) when they discovered the Botany Bay.