UA 556 then UA 3755 at Houston
Nashville → Houston → Lubbock
Timetable, Houston time
08:45UA 556 from Nashville at the gate
22:10UA 3755 to Lubbock leaves the gate
13 h 25 apart on the timetable
UA 3755 leaves 13 h 25 after UA 556 arrives on the timetable: more than half a day, so not a connection we count.