UA 4686 then WN 3628 at Denver
Little Rock → Denver → Tucson
Timetable, Denver time
15:11UA 4686 from Little Rock at the gate
15:10WN 3628 to Tucson leaves the gate
23 h 59 apart on the timetable, overnight
WN 3628 leaves 23 h 59 after UA 4686 arrives on the timetable: more than half a day, so not a connection we count.