AA 4259 then ET 3511 at O'Hare
St Louis → Chicago → Muscat
Timetable, Chicago time
18:59AA 4259 from St Louis at the gate
09:05ET 3511 to Muscat leaves the gate
14 h 06 apart on the timetable, overnight
ET 3511 leaves 14 h 06 after AA 4259 arrives on the timetable: more than half a day, so not a connection we count.