AA 5510 then DL 391 at Atlanta
Washington National → Atlanta → Reno
Timetable, Atlanta time
23:23AA 5510 from Washington National at the gate
19:50DL 391 to Reno leaves the gate
20 h 27 apart on the timetable, overnight
DL 391 leaves 20 h 27 after AA 5510 arrives on the timetable: more than half a day, so not a connection we count.