BA 1403 then BA 774 at Heathrow
Belfast City → London → Oslo
Timetable, London time
19:30BA 1403 from Belfast City at the gate
18:55BA 774 to Oslo leaves the gate
23 h 25 apart on the timetable, overnight
BA 774 leaves 23 h 25 after BA 1403 arrives on the timetable: more than half a day, so not a connection we count.