UA 879 then UA 3917 at Houston
London → Houston → Austin
Timetable, Houston time
14:40UA 879 from London at the gate
07:30UA 3917 to Austin leaves the gate
16 h 50 apart on the timetable, overnight
UA 3917 leaves 16 h 50 after UA 879 arrives on the timetable: more than half a day, so not a connection we count.