AA 1223 then WN 734 at Miami
Tampa → Miami → Denver
Timetable, Miami time
08:14AA 1223 from Tampa at the gate
14:35WN 734 to Denver leaves the gate
6 h 21 apart on the timetable
The last days
AA 1223 and WN 734 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.