AA 2870 then DL 2759 at Seattle
Philadelphia → Seattle → Denver
Timetable, Seattle time
12:09AA 2870 from Philadelphia at the gate
13:52DL 2759 to Denver leaves the gate
1 h 43 apart on the timetable
Seattle’s board gives a departure time for only about 57% of its flights, so many days show no gate time.
The last days
AA 2870 and DL 2759 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.