DL 5740 then DL 5704 at Boston
Philadelphia → Boston → Washington National
Timetable, Boston time
07:31DL 5740 from Philadelphia at the gate
21:45DL 5704 to Washington National leaves the gate
14 h 14 apart on the timetable
DL 5704 leaves 14 h 14 after DL 5740 arrives on the timetable: more than half a day, so not a connection we count.