B6 1554 then DL 5630 at Boston
Washington National → Boston → Charlotte
Timetable, Boston time
13:34B6 1554 from Washington National at the gate
11:25DL 5630 to Charlotte leaves the gate
21 h 51 apart on the timetable, overnight
DL 5630 leaves 21 h 51 after B6 1554 arrives on the timetable: more than half a day, so not a connection we count.