AA 1509 then CZ 438 at O'Hare
Boston → Chicago → Shanghai
Timetable, Chicago time
09:05AA 1509 from Boston at the gate
01:45CZ 438 to Shanghai leaves the gate
16 h 40 apart on the timetable, overnight
CZ 438 leaves 16 h 40 after AA 1509 arrives on the timetable: more than half a day, so not a connection we count.