JU 8510 then UA 805 at San Francisco
New York JFK → San Francisco → Seoul
Timetable, San Francisco time
23:54JU 8510 from New York JFK at the gate
23:45UA 805 to Seoul leaves the gatealso OZ 6621
23 h 51 apart on the timetable, overnight
UA 805 leaves 23 h 51 after JU 8510 arrives on the timetable: more than half a day, so not a connection we count.