WN 209 then UA 27 at Denver
St Louis → Denver → London
Timetable, Denver time
18:50WN 209 from St Louis at the gate
17:35UA 27 to London leaves the gate
22 h 45 apart on the timetable, overnight
UA 27 leaves 22 h 45 after WN 209 arrives on the timetable: more than half a day, so not a connection we count.