AA 1252 then AA 1266 at Miami
Philadelphia → Miami → Jacksonville
Timetable, Miami time
08:59AA 1252 from Philadelphia at the gate
09:50AA 1266 to Jacksonville leaves the gate
51 min apart on the timetable
The last days
AA 1252 and AA 1266 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.