AA's rules are pretty clear about this:
"Change of plans? We allow same-day confirmed changes on select flights for a fee, with some exceptions.
"Customers can stand by for a flight at no charge.
"Rules
"Your new flight must:
"Depart on the same day, from and to the same airports, as your original flight" (Emphasis added.)
Edited to add: See Post #6.
Last edited by guv1976; Jan 23, 2023 at 11:50 am