BA 1401 then BA 95 at Heathrow
Belfast City → London → Montréal
Timetable, London time
18:25BA 1401 from Belfast City at the gate
16:45BA 95 to Montréal leaves the gate
22 h 20 apart on the timetable, overnight
BA 95 leaves 22 h 20 after BA 1401 arrives on the timetable: more than half a day, so not a connection we count.