UA 1015 then CA 3174 at O'Hare
Boston → Chicago → Guangzhou
Timetable, Chicago time
20:40UA 1015 from Boston at the gate
13:40CA 3174 to Guangzhou leaves the gate
17 h apart on the timetable, overnight
CA 3174 leaves 17 h after UA 1015 arrives on the timetable: more than half a day, so not a connection we count.