DL 26 then DL 2398 at Atlanta
Seoul → Atlanta → New York JFK
Timetable, Atlanta time
18:55DL 26 from Seoul at the gate
15:16DL 2398 to New York JFK leaves the gate
20 h 21 apart on the timetable, overnight
DL 2398 leaves 20 h 21 after DL 26 arrives on the timetable: more than half a day, so not a connection we count.