B6 837 then DL 5101 at Detroit
Boston → Detroit → Louisville
Timetable, Detroit time
11:19B6 837 from Boston at the gate
08:29DL 5101 to Louisville leaves the gate
21 h 10 apart on the timetable, overnight
DL 5101 leaves 21 h 10 after B6 837 arrives on the timetable: more than half a day, so not a connection we count.