<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by Plato90s:
This is from the Condition of Carriage
You must check-in at least 30 minutes before scheduled departure time, and be present at the departure gate, to retain your reservation and a seat. </font>
I think that's for International. This is what I found:
CHECK-IN REQUIREMENTS
Customers must comply with minimum check-in requirements to retain their seats on the flight on which they are confirmed. When travel is completely within the U.S., recommended check-in time is 90 minutes prior to departure. You must check-in at least 15 minutes before scheduled departure time, and be present at the departure gate, to retain your reservation and a seat.
So only 15 minutes