F9 4567 then UA 1955 at Denver
St Louis → Denver → Los Angeles
Timetable, Denver time
21:30F9 4567 from St Louis at the gate
19:09UA 1955 to Los Angeles leaves the gate
21 h 39 apart on the timetable, overnight
UA 1955 leaves 21 h 39 after F9 4567 arrives on the timetable: more than half a day, so not a connection we count.