UA 580 then UA 3755 at Houston
Los Angeles → Houston → Lubbock
Timetable, Houston time
05:13UA 580 from Los Angeles at the gate
22:10UA 3755 to Lubbock leaves the gate
16 h 57 apart on the timetable
UA 3755 leaves 16 h 57 after UA 580 arrives on the timetable: more than half a day, so not a connection we count.