U2 8286 then U2 821 at Gatwick
Catania → London → Belfast International
Timetable, London time
15:00U2 8286 from Catania at the gate
12:15U2 821 to Belfast International leaves the gate
21 h 15 apart on the timetable, overnight
U2 821 leaves 21 h 15 after U2 8286 arrives on the timetable: more than half a day, so not a connection we count.