DL 5600 then DL 5665 at Boston
Washington National → Boston → Richmond
Timetable, Boston time
17:11DL 5600 from Washington National at the gate
15:23DL 5665 to Richmond leaves the gate
22 h 12 apart on the timetable, overnight
DL 5665 leaves 22 h 12 after DL 5600 arrives on the timetable: more than half a day, so not a connection we count.