WN 3057 then B6 2255 at Boston
Nashville → Boston → Washington National
Timetable, Boston time
19:05WN 3057 from Nashville at the gate
18:20B6 2255 to Washington National leaves the gate
23 h 15 apart on the timetable, overnight
B6 2255 leaves 23 h 15 after WN 3057 arrives on the timetable: more than half a day, so not a connection we count.