WN 591 then WN 660 at Denver
Baltimore → Denver → Tulsa
Timetable, Denver time
10:15WN 591 from Baltimore at the gate
18:05WN 660 to Tulsa leaves the gate
7 h 50 apart on the timetable
The last days
WN 591 and WN 660 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.