UA 3879 then UA 4074 at Houston
Amarillo → Houston → Nashville
Timetable, Houston time
17:48UA 3879 from Amarillo at the gate
07:35UA 4074 to Nashville leaves the gate
13 h 47 apart on the timetable, overnight
UA 4074 leaves 13 h 47 after UA 3879 arrives on the timetable: more than half a day, so not a connection we count.