UA 2340 then CA 1020 at O'Hare
Seattle (SEA) → Chicago → Shanghai
Timetable, Chicago time
20:40UA 2340 from Seattle (SEA) at the gate
19:30CA 1020 to Shanghai leaves the gate
22 h 50 apart on the timetable, overnight
CA 1020 leaves 22 h 50 after UA 2340 arrives on the timetable: more than half a day, so not a connection we count.