UA 4576 then CA 3174 at O'Hare
Greensboro → Chicago → Guangzhou
Timetable, Chicago time
19:00UA 4576 from Greensboro at the gate
13:40CA 3174 to Guangzhou leaves the gate
18 h 40 apart on the timetable, overnight
CA 3174 leaves 18 h 40 after UA 4576 arrives on the timetable: more than half a day, so not a connection we count.