AA 990 then ET 3511 at O'Hare
Phoenix → Chicago → Muscat
Timetable, Chicago time
11:39AA 990 from Phoenix at the gate
09:05ET 3511 to Muscat leaves the gate
21 h 26 apart on the timetable, overnight
ET 3511 leaves 21 h 26 after AA 990 arrives on the timetable: more than half a day, so not a connection we count.