UA 3901 then AC 508 at O'Hare
Minneapolis → Chicago → Toronto Pearson
Timetable, Chicago time
13:51UA 3901 from Minneapolis at the gate
16:30AC 508 to Toronto Pearson leaves the gate
2 h 39 apart on the timetable
The last days
UA 3901 and AC 508 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.