F9 2350 then UA 5421 at Denver
Las Vegas → Denver → Lubbock
Timetable, Denver time
14:41F9 2350 from Las Vegas at the gate
14:04UA 5421 to Lubbock leaves the gate
23 h 23 apart on the timetable, overnight
UA 5421 leaves 23 h 23 after F9 2350 arrives on the timetable: more than half a day, so not a connection we count.