AA 2123 then ET 3511 at O'Hare
Los Angeles → Chicago → Muscat
Timetable, Chicago time
20:04AA 2123 from Los Angeles at the gate
09:05ET 3511 to Muscat leaves the gate
13 h 01 apart on the timetable, overnight
ET 3511 leaves 13 h 01 after AA 2123 arrives on the timetable: more than half a day, so not a connection we count.