UA 2258 then CA 3174 at O'Hare
Denver → Chicago → Guangzhou
Timetable, Chicago time
22:46UA 2258 from Denver at the gate
22:40CA 3174 to Guangzhou leaves the gate
23 h 54 apart on the timetable, overnight
CA 3174 leaves 23 h 54 after UA 2258 arrives on the timetable: more than half a day, so not a connection we count.