DL 9976 then DL 5695 at Boston
Miami → Boston → Washington National
Timetable, Boston time
02:50DL 9976 from Miami at the gate
07:40DL 5695 to Washington National leaves the gate
4 h 50 apart on the timetable
The last days
DL 9976 and DL 5695 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.