DL 5720 then B6 477 at JFK
Boston → New York → Jacksonville
Timetable, New York time
10:37DL 5720 from Boston at the gate
06:55B6 477 to Jacksonville leaves the gate
20 h 18 apart on the timetable, overnight
B6 477 leaves 20 h 18 after DL 5720 arrives on the timetable: more than half a day, so not a connection we count.