DL 1874 then UA 3917 at Houston
Atlanta → Houston → Austin
Timetable, Houston time
15:47DL 1874 from Atlanta at the gate
07:30UA 3917 to Austin leaves the gate
15 h 43 apart on the timetable, overnight
UA 3917 leaves 15 h 43 after DL 1874 arrives on the timetable: more than half a day, so not a connection we count.