WN 818 then WN 643 at Denver
Buffalo → Denver → Orlando
Timetable, Denver time
16:20WN 818 from Buffalo at the gate
13:25WN 643 to Orlando leaves the gate
21 h 05 apart on the timetable, overnight
WN 643 leaves 21 h 05 after WN 818 arrives on the timetable: more than half a day, so not a connection we count.