UA 255 then UA 3917 at Houston
Newark → Houston → Austin
Timetable, Houston time
10:38UA 255 from Newark at the gate
07:30UA 3917 to Austin leaves the gate
20 h 52 apart on the timetable, overnight
UA 3917 leaves 20 h 52 after UA 255 arrives on the timetable: more than half a day, so not a connection we count.