U2 8306 then U2 8421 at Gatwick
Milan → London → Nice
Timetable, London time
20:55U2 8306 from Milan at the gate
17:25U2 8421 to Nice leaves the gate
20 h 30 apart on the timetable, overnight
U2 8421 leaves 20 h 30 after U2 8306 arrives on the timetable: more than half a day, so not a connection we count.