F9 4567 then UA 2173 at Denver
St Louis → Denver → Hayden
Timetable, Denver time
21:30F9 4567 from St Louis at the gate
19:29UA 2173 to Hayden leaves the gate
21 h 59 apart on the timetable, overnight
UA 2173 leaves 21 h 59 after F9 4567 arrives on the timetable: more than half a day, so not a connection we count.