AA 947 then CZ 2502 at O'Hare
Boston → Chicago → Shanghai
Timetable, Chicago time
09:30AA 947 from Boston at the gate
01:45CZ 2502 to Shanghai leaves the gate
16 h 15 apart on the timetable, overnight
CZ 2502 leaves 16 h 15 after AA 947 arrives on the timetable: more than half a day, so not a connection we count.