DL 2398 then AA 4640 at JFK
Atlanta → New York → Washington National
Timetable, New York time
17:36DL 2398 from Atlanta at the gate
08:28AA 4640 to Washington National leaves the gate
14 h 52 apart on the timetable, overnight
AA 4640 leaves 14 h 52 after DL 2398 arrives on the timetable: more than half a day, so not a connection we count.