AA 4040 then AS 2257 at Phoenix
Denver → Phoenix → San Diego
Timetable, Phoenix time
07:07AA 4040 from Denver at the gate
08:00AS 2257 to San Diego leaves the gate
53 min apart on the timetable
The last days
AA 4040 and AS 2257 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.