Originally Posted by
JDiver
AFAIK, check-in time does not affect upgrades processing.
Time of request affects upgrades, but for standby for another flight, the time of check-in is the status tiebreaker for the standby list (e.g. how they determine who is first when two EXP's are on the list, etc.), or at least has been for as long as I've been flying AA. This could have changed with the #newAmerican, however.