Originally Posted by
mr_edward_p
or get on-line and check-in 24 hours before your flight.
Just to reiterate, ideally exactly 24 hours before flight time. I open a window with the
NIST clock and try to get it to the second.
One more point not mentioned is that originating flights will usually have better seating options than through flights. The latter will have passengers from the prior segment filling the more desired seats before boarding starts.