AS 421 then WN 451 at Denver
Seattle → Denver → Tulsa
Timetable, Denver time
17:39AS 421 from Seattle at the gate
17:35WN 451 to Tulsa leaves the gate
23 h 56 apart on the timetable, overnight
WN 451 leaves 23 h 56 after AS 421 arrives on the timetable: more than half a day, so not a connection we count.