Assuming the departure times are at the departure point and the arrival times are at this common arriving airport, I cannot figure out where (given time zones) this could possibly be. Around two hours (and 2 time zones) east of LA, two hours east and one time zones from Denver, 3 hours north of Dallas … given the odds making, the easy answer would have been Vegas (baby), but that’s no 3 hour flight from LA … it is a 3+ hour drive.
Apart from the St. Paul flight, the times are reasonably plausible for New York, provided you assume they’re all written in New York time. (Cue flamewar about how New Yorkers think New York is the center of the universe.)
I agree with J-L @ 2, but in response to @3: This is a comic airport, not a real one. Real signs in real airports list only the local time: the “Departures” table lists only the times that the flights (are supposed to) take off, and the arrival table lists only the times that the flights (are supposed to) arrive. The corresponding landing and take off times at the “other” airport are never shown.