AA 712 then UA 3596 at Charlotte
St Louis → Charlotte → Newark
Timetable, Charlotte time
10:13AA 712 from St Louis at the gate
10:52UA 3596 to Newark leaves the gate
39 min apart on the timetable
The last days
AA 712 and UA 3596 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.