UA 1371 then DL 2709 at Houston
St Louis → Houston → Atlanta
Timetable, Houston time
08:35UA 1371 from St Louis at the gate
08:05DL 2709 to Atlanta leaves the gate
23 h 30 apart on the timetable, overnight
DL 2709 leaves 23 h 30 after UA 1371 arrives on the timetable: more than half a day, so not a connection we count.