B6 8582 then DL 169 at Boston
Montreal → Boston → New York JFK
Timetable, Boston time
12:03B6 8582 from Montreal at the gate
12:52DL 169 to New York JFK leaves the gate
49 min apart on the timetable
The last days
B6 8582 and DL 169 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.