U2 8306 then U2 819 at Gatwick
Milan → London → Belfast International
Timetable, London time
20:55U2 8306 from Milan at the gate
15:40U2 819 to Belfast International leaves the gate
18 h 45 apart on the timetable, overnight
U2 819 leaves 18 h 45 after U2 8306 arrives on the timetable: more than half a day, so not a connection we count.