UA 3878 then DL 1682 at Houston
IAB → Houston → Atlanta
Timetable, Houston time
22:40UA 3878 from IAB at the gate
12:32DL 1682 to Atlanta leaves the gate
13 h 52 apart on the timetable, overnight
DL 1682 leaves 13 h 52 after UA 3878 arrives on the timetable: more than half a day, so not a connection we count.