Off the top of my head and going strictly by (one interpretation of) evidence in episodes and movies...
TWoK: 2283 (the bottle of Romulan Ale)
-15 = 2268 for "Space Seed"
VOY: "Q2" says the 5 year mission ended in 2270, and TMP says it's been 2.5 years since the 5YM ended. So TMP = 2272. So it's roughly 11 years between TMP and TWoK.
Unless you count forward by 200 years from 1996 (cited in both "Space Seed" and WoK), which totally screws up everything...
is correct - some fans back in the early 80's believed that Wrath of Kahn completely ignored The Motion Picture. There is some debate on the subject in the old Best of Trek books. I personally see the "at peace with himself" Spock in WoK as a continuation of Spock's epiphany about emotion and feeling in TMP, but it could be argued that he reached this equilibrium by other means in a Trekverse where TMP didn't occur.