UA 4301 then UA 5091 at Houston
Lubbock → Houston → Chattanooga
Timetable, Houston time
18:41UA 4301 from Lubbock at the gate
12:55UA 5091 to Chattanooga leaves the gate
18 h 14 apart on the timetable, overnight
UA 5091 leaves 18 h 14 after UA 4301 arrives on the timetable: more than half a day, so not a connection we count.