AA 2016 then UA 3923 at Phoenix
Reno → Phoenix → Denver
Timetable, Phoenix time
17:59AA 2016 from Reno at the gate
22:10UA 3923 to Denver leaves the gate
4 h 11 apart on the timetable
The last days
AA 2016 and UA 3923 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.