WN 1663 then WN 596 at Denver
Albuquerque → Denver → St Louis
Timetable, Denver time
12:10WN 1663 from Albuquerque at the gate
18:45WN 596 to St Louis leaves the gate
6 h 35 apart on the timetable
The last days
WN 1663 and WN 596 weren’t both flown 15 min to 12 h apart in the last 21 days.
Statistics from past flights, not live flight information. Always check times and your connection with your airline, and don’t base travel or booking decisions on these numbers.