DL 637 then CA 3174 at O'Hare
Seattle (SEA) → Chicago → Guangzhou
Timetable, Chicago time
16:47DL 637 from Seattle (SEA) at the gate
13:40CA 3174 to Guangzhou leaves the gate
20 h 53 apart on the timetable, overnight
CA 3174 leaves 20 h 53 after DL 637 arrives on the timetable: more than half a day, so not a connection we count.