AA 1225 then B6 1555 at Boston
Miami (MIA) → Boston → Washington National
Timetable, Boston time
14:10AA 1225 from Miami (MIA) at the gate
14:09B6 1555 to Washington National leaves the gate
23 h 59 apart on the timetable, overnight
B6 1555 leaves 23 h 59 after AA 1225 arrives on the timetable: more than half a day, so not a connection we count.