AA 509 then PD 544 at Miami
Houston → Miami → Toronto
Timetable, Miami time
09:45AA 509 from Houston at the gate
14:00PD 544 to Toronto leaves the gate
4 h 15 apart on the timetable
The last days
AA 509 and PD 544 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.