QR 2015 then KL 7451 at San Francisco
Seattle → San Francisco → New York JFK
Timetable, San Francisco time
14:10QR 2015 from Seattle at the gate
20:50KL 7451 to New York JFK leaves the gate
6 h 40 apart on the timetable
The last days
QR 2015 and KL 7451 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.