BA 1399 then BA 782 at Heathrow
Belfast City → London → Stockholm
Timetable, London time
16:25BA 1399 from Belfast City at the gate
15:55BA 782 to Stockholm leaves the gate
23 h 30 apart on the timetable, overnight
BA 782 leaves 23 h 30 after BA 1399 arrives on the timetable: more than half a day, so not a connection we count.