UA 4271 then UA 3917 at Houston
Brownsville → Houston → Austin
Timetable, Houston time
10:37UA 4271 from Brownsville at the gate
07:30UA 3917 to Austin leaves the gate
20 h 53 apart on the timetable, overnight
UA 3917 leaves 20 h 53 after UA 4271 arrives on the timetable: more than half a day, so not a connection we count.