U2 8284 then U2 8421 at Gatwick
Milan → London → Nice
Timetable, London time
20:15U2 8284 from Milan at the gate
17:35U2 8421 to Nice leaves the gate
21 h 20 apart on the timetable, overnight
U2 8421 leaves 21 h 20 after U2 8284 arrives on the timetable: more than half a day, so not a connection we count.