UA 1504 then CA 3174 at O'Hare
New York LaGuardia → Chicago → Guangzhou
Timetable, Chicago time
17:20UA 1504 from New York LaGuardia at the gate
13:40CA 3174 to Guangzhou leaves the gate
20 h 20 apart on the timetable, overnight
CA 3174 leaves 20 h 20 after UA 1504 arrives on the timetable: more than half a day, so not a connection we count.