WN 1122 then WN 399 at Phoenix
Denver → Phoenix → St Louis
Timetable, Phoenix time
07:40WN 1122 from Denver at the gate
12:00WN 399 to St Louis leaves the gate
4 h 20 apart on the timetable
The last days
WN 1122 and WN 399 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.