AA 317 then AA 819 at O'Hare
Denver → Chicago → New York JFK
Timetable, Chicago time
10:04AA 317 from Denver at the gate
10:34AA 819 to New York JFK leaves the gate
30 min apart on the timetable
The last days
AA 317 and AA 819 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.