AC 138 then AC 428 at Toronto Pearson
Calgary → Toronto → Montréal
Timetable, Toronto time
15:35AC 138 from Calgary at the gate
22:30AC 428 to Montréal leaves the gate
6 h 55 apart on the timetable
The last days
AC 138 and AC 428 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.