AA 9782 then CZ 2504 at O'Hare
Boston → Chicago → Shanghai
Timetable, Chicago time
13:14AA 9782 from Boston at the gate
19:15CZ 2504 to Shanghai leaves the gate
6 h 01 apart on the timetable
The last days
AA 9782 and CZ 2504 weren’t both flown 15 min to 12 h apart in the last 21 days.
Statistics from past flights, not live flight information. Always check times and your connection with your airline, and don’t base travel or booking decisions on these numbers.