AA 5503 then B6 1396 at Atlanta
Washington National → Atlanta → Boston
Timetable, Atlanta time
16:25AA 5503 from Washington National at the gate
16:22B6 1396 to Boston leaves the gate
23 h 57 apart on the timetable, overnight
B6 1396 leaves 23 h 57 after AA 5503 arrives on the timetable: more than half a day, so not a connection we count.