AA 2921 then ET 3511 at O'Hare
Buffalo → Chicago → Muscat
Timetable, Chicago time
19:00AA 2921 from Buffalo at the gate
09:05ET 3511 to Muscat leaves the gate
14 h 05 apart on the timetable, overnight
ET 3511 leaves 14 h 05 after AA 2921 arrives on the timetable: more than half a day, so not a connection we count.