B6 1254 then DL 2677 at Boston
Washington National → Boston → Nashville
Timetable, Boston time
15:00B6 1254 from Washington National at the gate
14:45DL 2677 to Nashville leaves the gate
23 h 45 apart on the timetable, overnight
DL 2677 leaves 23 h 45 after B6 1254 arrives on the timetable: more than half a day, so not a connection we count.