F9 2297 then DL 1682 at Atlanta
Philadelphia → Atlanta → Houston
Timetable, Atlanta time
11:07F9 2297 from Philadelphia at the gate
14:37DL 1682 to Houston leaves the gate
3 h 30 apart on the timetable
The last days
F9 2297 and DL 1682 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.