AA 2504 then ET 3511 at O'Hare
Houston → Chicago → Muscat
Timetable, Chicago time
14:15AA 2504 from Houston at the gate
09:05ET 3511 to Muscat leaves the gate
18 h 50 apart on the timetable, overnight
ET 3511 leaves 18 h 50 after AA 2504 arrives on the timetable: more than half a day, so not a connection we count.