AA 4635 then CZ 2550 at O'Hare
Washington National → Chicago → Guangzhou
Timetable, Chicago time
23:30AA 4635 from Washington National at the gate
23:25CZ 2550 to Guangzhou leaves the gate
23 h 55 apart on the timetable, overnight
CZ 2550 leaves 23 h 55 after AA 4635 arrives on the timetable: more than half a day, so not a connection we count.