DL 4097 then UA 521 at Atlanta
South Bend → Atlanta → Houston
Timetable, Atlanta time
15:59DL 4097 from South Bend at the gate
15:57UA 521 to Houston leaves the gate
23 h 58 apart on the timetable, overnight
UA 521 leaves 23 h 58 after DL 4097 arrives on the timetable: more than half a day, so not a connection we count.