BA 309 then BA 1402 at Heathrow
Paris Charles de Gaulle → London → Belfast City
Timetable, London time
15:25BA 309 from Paris Charles de Gaulle at the gate
15:20BA 1402 to Belfast City leaves the gate
23 h 55 apart on the timetable, overnight
BA 1402 leaves 23 h 55 after BA 309 arrives on the timetable: more than half a day, so not a connection we count.