I did a search and I am pretty sure I saw the answer to this before, but I couldn't narrow down the results enough.

If a flight is scheduled to depart on Dec 31 @ 23:59 but arrives Jan 1, do the miles count towards the departure or arrival year? I recall it is the departure year.

Is it the scheduled or actual departure/arrival time that matters? What if the flight is delayed 6 hours?

Thanks,
greywolf