B6 816 then 1I 896 at JFK
San Francisco → New York → Boston
Timetable, New York time
00:56B6 816 from San Francisco at the gate
09:001I 896 to Boston leaves the gate
8 h 04 apart on the timetable
The last days
B6 816 and 1I 896 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.