DL 5592 then DL 5837 at Boston
Washington National → Boston → Charlotte
Timetable, Boston time
15:21DL 5592 from Washington National at the gate
15:10DL 5837 to Charlotte leaves the gate
23 h 49 apart on the timetable, overnight
DL 5837 leaves 23 h 49 after DL 5592 arrives on the timetable: more than half a day, so not a connection we count.