WN 4626 then B6 994 at Denver
Nashville → Denver → Boston
Timetable, Denver time
18:00WN 4626 from Nashville at the gate
14:00B6 994 to Boston leaves the gate
20 h apart on the timetable, overnight
B6 994 leaves 20 h after WN 4626 arrives on the timetable: more than half a day, so not a connection we count.