UA 1940 then WN 1749 at Denver
Omaha → Denver → Dallas
Timetable, Denver time
10:31UA 1940 from Omaha at the gate
05:35WN 1749 to Dallas leaves the gate
19 h 04 apart on the timetable, overnight
WN 1749 leaves 19 h 04 after UA 1940 arrives on the timetable: more than half a day, so not a connection we count.