UA 2135 then UA 3917 at Houston
Seattle → Houston → Austin
Timetable, Houston time
13:21UA 2135 from Seattle at the gate
07:30UA 3917 to Austin leaves the gate
18 h 09 apart on the timetable, overnight
UA 3917 leaves 18 h 09 after UA 2135 arrives on the timetable: more than half a day, so not a connection we count.