AA 1968 then CZ 2502 at O'Hare
Tucson → Chicago → Shanghai
Timetable, Chicago time
20:20AA 1968 from Tucson at the gate
13:55CZ 2502 to Shanghai leaves the gate
17 h 35 apart on the timetable, overnight
CZ 2502 leaves 17 h 35 after AA 1968 arrives on the timetable: more than half a day, so not a connection we count.