BJ 510 then U2 3798 at Charles de Gaulle
Tunis → Paris → Milan
Timetable, Paris time
09:35BJ 510 from Tunis at the gate
13:05U2 3798 to Milan leaves the gate
3 h 30 apart on the timetable
Charles de Gaulle’s board gives an arrival time for only about 51% of its flights, so many days show no gate time.
The last days
BJ 510 and U2 3798 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.