AA 866 then CZ 2502 at O'Hare
Boston → Chicago → Shanghai
Timetable, Chicago time
15:37AA 866 from Boston at the gate
13:55CZ 2502 to Shanghai leaves the gate
22 h 18 apart on the timetable, overnight
CZ 2502 leaves 22 h 18 after AA 866 arrives on the timetable: more than half a day, so not a connection we count.