B6 478 then DL 2500 at JFK
Jacksonville → New York → Miami
Timetable, New York time
18:00B6 478 from Jacksonville at the gate
15:25DL 2500 to Miami leaves the gate
21 h 25 apart on the timetable, overnight
DL 2500 leaves 21 h 25 after B6 478 arrives on the timetable: more than half a day, so not a connection we count.