CA 993 then PD 277 at Toronto Pearson
Beijing → Toronto → Calgary
Timetable, Toronto time
12:10CA 993 from Beijing at the gate
20:45PD 277 to Calgary leaves the gate
8 h 35 apart on the timetable
The last days
CA 993 and PD 277 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.