B6 1234 then B6 8371 at Boston
San Francisco → Boston → New York JFK
Timetable, Boston time
23:58B6 1234 from San Francisco at the gate
07:00B6 8371 to New York JFK leaves the gate
7 h 02 apart on the timetable, overnight
The last days
B6 1234 and B6 8371 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.