AA 2389 then UA 5201 at O'Hare
Calgary → Chicago → Milwaukee
Timetable, Chicago time
18:44AA 2389 from Calgary at the gate
20:00UA 5201 to Milwaukee leaves the gate
1 h 16 apart on the timetable
The last days
AA 2389 and UA 5201 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.