UA 5704 then CA 3174 at O'Hare
Toronto Pearson → Chicago → Guangzhou
Timetable, Chicago time
20:48UA 5704 from Toronto Pearson at the gate
17:25CA 3174 to Guangzhou leaves the gate
20 h 37 apart on the timetable, overnight
CA 3174 leaves 20 h 37 after UA 5704 arrives on the timetable: more than half a day, so not a connection we count.