AA 4635 then CZ 2508 at O'Hare
Washington National → Chicago → Shanghai
Timetable, Chicago time
23:40AA 4635 from Washington National at the gate
20:50CZ 2508 to Shanghai leaves the gate
21 h 10 apart on the timetable, overnight
CZ 2508 leaves 21 h 10 after AA 4635 arrives on the timetable: more than half a day, so not a connection we count.