DL 1981 then DL 5615 at Boston
Fort Lauderdale → Boston → Louisville
Timetable, Boston time
10:20DL 1981 from Fort Lauderdale at the gate
09:45DL 5615 to Louisville leaves the gate
23 h 25 apart on the timetable, overnight
DL 5615 leaves 23 h 25 after DL 1981 arrives on the timetable: more than half a day, so not a connection we count.