UA 3237 then UA 3917 at Houston
Louisville → Houston → Austin
Timetable, Houston time
12:15UA 3237 from Louisville at the gate
07:30UA 3917 to Austin leaves the gate
19 h 15 apart on the timetable, overnight
UA 3917 leaves 19 h 15 after UA 3237 arrives on the timetable: more than half a day, so not a connection we count.