AA 3303 then UA 3917 at Houston
Philadelphia → Houston → Austin
Timetable, Houston time
11:54AA 3303 from Philadelphia at the gate
07:30UA 3917 to Austin leaves the gate
19 h 36 apart on the timetable, overnight
UA 3917 leaves 19 h 36 after AA 3303 arrives on the timetable: more than half a day, so not a connection we count.