AA 2359 then UA 3755 at O'Hare
Buffalo → Chicago → Denver
Timetable, Chicago time
09:05AA 2359 from Buffalo at the gate
18:37UA 3755 to Denver leaves the gate
9 h 32 apart on the timetable
Today
From the airport’s board at 05:39 Chicago time
09:05AA 2359 due at the gate, no estimate yet
18:37UA 3755 due to leave, no estimate yet
9 h 32 between the gates, on these times
The last days
AA 2359 and UA 3755 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.