AA 1866 then AA 2615 at Philadelphia
Denver → Philadelphia → Boston
Timetable, Philadelphia time
05:35AA 1866 from Denver at the gate
10:49AA 2615 to Boston leaves the gate
5 h 14 apart on the timetable
The last days
AA 1866 and AA 2615 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.