DL 8842 then AA 9784 at Philadelphia
Washington → Philadelphia → Boston
Timetable, Philadelphia time
02:42DL 8842 from Washington at the gate
09:02AA 9784 to Boston leaves the gate
6 h 20 apart on the timetable
The last days
DL 8842 and AA 9784 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.