AC 864 then BA 418 at Heathrow
Montréal → London → Luxembourg
Timetable, London time
07:10AC 864 from Montréal at the gate
06:05BA 418 to Luxembourg leaves the gate
22 h 55 apart on the timetable, overnight
BA 418 leaves 22 h 55 after AC 864 arrives on the timetable: more than half a day, so not a connection we count.