UA 4301 then UA 4236 at Houston
Lubbock → Houston → Harlingen
Timetable, Houston time
18:41UA 4301 from Lubbock at the gate
12:00UA 4236 to Harlingen leaves the gate
17 h 19 apart on the timetable, overnight
UA 4236 leaves 17 h 19 after UA 4301 arrives on the timetable: more than half a day, so not a connection we count.