AA 3308 then DL 9964 at Boston
Philadelphia → Boston → Atlanta
Timetable, Boston time
09:03AA 3308 from Philadelphia at the gate
15:00DL 9964 to Atlanta leaves the gate
5 h 57 apart on the timetable
The last days
AA 3308 and DL 9964 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.