DL 5641 then DL 5689 at Boston
Cleveland → Boston → Washington National
Timetable, Boston time
19:35DL 5641 from Cleveland at the gate
16:00DL 5689 to Washington National leaves the gate
20 h 25 apart on the timetable, overnight
DL 5689 leaves 20 h 25 after DL 5641 arrives on the timetable: more than half a day, so not a connection we count.