DL 5234 then DL 2128 at Atlanta
Knoxville → Atlanta → Denver
Timetable, Atlanta time
10:19DL 5234 from Knoxville at the gate
10:40DL 2128 to Denver leaves the gate
21 min apart on the timetable
The last days
DL 5234 and DL 2128 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.