LX 87 then BA 725 at Zurich
Montréal → Zurich → London Heathrow
Timetable, Zurich time
06:15LX 87 from Montréal at the gate
06:00BA 725 to London Heathrow leaves the gate
23 h 45 apart on the timetable, overnight
BA 725 leaves 23 h 45 after LX 87 arrives on the timetable: more than half a day, so not a connection we count.