AA 2253 then CA 1056 at O'Hare
San Francisco → Chicago → Shanghai
Timetable, Chicago time
23:55AA 2253 from San Francisco at the gate
21:15CA 1056 to Shanghai leaves the gate
21 h 20 apart on the timetable, overnight
CA 1056 leaves 21 h 20 after AA 2253 arrives on the timetable: more than half a day, so not a connection we count.