AC 1731 then UA 3804 at Phoenix
Montréal → Phoenix → Denver
Timetable, Phoenix time
21:38AC 1731 from Montréal at the gate
22:30UA 3804 to Denver leaves the gate
52 min apart on the timetable
The last days
AC 1731 and UA 3804 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.