UA 6228 then DL 2709 at Houston
Louisville → Houston → Atlanta
Timetable, Houston time
10:55UA 6228 from Louisville at the gate
08:05DL 2709 to Atlanta leaves the gate
21 h 10 apart on the timetable, overnight
DL 2709 leaves 21 h 10 after UA 6228 arrives on the timetable: more than half a day, so not a connection we count.