AA 4788 then DL 5610 at Boston
Buffalo → Boston → Philadelphia
Timetable, Boston time
08:36AA 4788 from Buffalo at the gate
20:40DL 5610 to Philadelphia leaves the gate
12 h 04 apart on the timetable
DL 5610 leaves 12 h 04 after AA 4788 arrives on the timetable: more than half a day, so not a connection we count.