DL 1523 then DL 5613 at Boston
Washington National → Boston → Nashville
Timetable, Boston time
13:34DL 1523 from Washington National at the gate
08:50DL 5613 to Nashville leaves the gate
19 h 16 apart on the timetable, overnight
DL 5613 leaves 19 h 16 after DL 1523 arrives on the timetable: more than half a day, so not a connection we count.