[bluGill]

I also care about departure time. If I arrive with one minute to spare (counting security and check in) but the plane leaves 2 minutes early I don't get their on time through no fault of my own. If I'm even a second late I accept it is my fault.

[sokoloff]

Airlines I've flown publish and abide the door-closing time. (For Delta domestic flights, it's 15 minutes before scheduled departure, 30 for int'l. I think they put 20 minutes on domestic boarding passes as a buffer against watch skew arguments.)

I've seen the gate agents paying scrupulous attention to that, to ensure they don't close the gate early if any pax who have checked in haven't boarded.