AA 3346 then AA 4639 at Boston
Washington National → Boston → New York JFK
Timetable, Boston time
23:59AA 3346 from Washington National at the gate
06:01AA 4639 to New York JFK leaves the gate
6 h 02 apart on the timetable, overnight
The last days
AA 3346 and AA 4639 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.