BA 1395 then BA 934 at Heathrow
Belfast City → London → Düsseldorf
Timetable, London time
13:05BA 1395 from Belfast City at the gate
12:45BA 934 to Düsseldorf leaves the gate
23 h 40 apart on the timetable, overnight
BA 934 leaves 23 h 40 after BA 1395 arrives on the timetable: more than half a day, so not a connection we count.