DL 5845 then AA 5256 at Philadelphia
Boston → Philadelphia → Jacksonville
Timetable, Philadelphia time
08:20DL 5845 from Boston at the gate
21:15AA 5256 to Jacksonville leaves the gate
12 h 55 apart on the timetable
AA 5256 leaves 12 h 55 after DL 5845 arrives on the timetable: more than half a day, so not a connection we count.