EC 3749 then IB 5340 at Barcelona
Milan → Barcelona → Rome
Timetable, Barcelona time
08:40EC 3749 from Milan at the gate
12:55IB 5340 to Rome leaves the gatealso LL 5340, LA 5839
4 h 15 apart on the timetable
The last days
EC 3749 and IB 5340 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.