UA 1593 then B6 316 at San Francisco
Newark → San Francisco → New York JFK
Timetable, San Francisco time
11:41UA 1593 from Newark at the gatealso VA 8514, NZ 9120
12:30B6 316 to New York JFK leaves the gate
49 min apart on the timetable
The last days
UA 1593 and B6 316 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.