AA 5510 then DL 4970 at Atlanta
Washington National → Atlanta → Allentown
Timetable, Atlanta time
23:23AA 5510 from Washington National at the gate
20:10DL 4970 to Allentown leaves the gate
20 h 47 apart on the timetable, overnight
DL 4970 leaves 20 h 47 after AA 5510 arrives on the timetable: more than half a day, so not a connection we count.