AA 1200 then ET 3511 at O'Hare
Washington National → Chicago → Muscat
Timetable, Chicago time
11:34AA 1200 from Washington National at the gate
09:05ET 3511 to Muscat leaves the gate
21 h 31 apart on the timetable, overnight
ET 3511 leaves 21 h 31 after AA 1200 arrives on the timetable: more than half a day, so not a connection we count.