DL 939 then DL 5123 at JFK
Los Angeles → New York → Jacksonville
Timetable, New York time
20:59DL 939 from Los Angeles at the gate
18:20DL 5123 to Jacksonville leaves the gate
21 h 21 apart on the timetable, overnight
DL 5123 leaves 21 h 21 after DL 939 arrives on the timetable: more than half a day, so not a connection we count.