AA 2389 then DL 1979 at O'Hare
Calgary → Chicago → Salt Lake City
Timetable, Chicago time
18:44AA 2389 from Calgary at the gate
19:17DL 1979 to Salt Lake City leaves the gate
33 min apart on the timetable
The last days
AA 2389 and DL 1979 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.