KE 81 then DL 917 at JFK
Seoul → New York → Salt Lake City
Timetable, New York time
10:00KE 81 from Seoul at the gate
09:30DL 917 to Salt Lake City leaves the gate
23 h 30 apart on the timetable, overnight
DL 917 leaves 23 h 30 after KE 81 arrives on the timetable: more than half a day, so not a connection we count.