UA 4301 then UA 4583 at Houston
Lubbock → Houston → Huntsville
Timetable, Houston time
18:41UA 4301 from Lubbock at the gate
09:45UA 4583 to Huntsville leaves the gate
15 h 04 apart on the timetable, overnight
UA 4583 leaves 15 h 04 after UA 4301 arrives on the timetable: more than half a day, so not a connection we count.