AA 6479 then UA 5207 at O'Hare
Milwaukee → Chicago → Denver
Timetable, Chicago time
10:05AA 6479 from Milwaukee at the gate
21:00UA 5207 to Denver leaves the gate
10 h 55 apart on the timetable
The last days
AA 6479 and UA 5207 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.