AC 864 then BA 590 at Heathrow
Montréal → London → Venezia
Timetable, London time
07:10AC 864 from Montréal at the gate
06:10BA 590 to Venezia leaves the gate
23 h apart on the timetable, overnight
BA 590 leaves 23 h after AC 864 arrives on the timetable: more than half a day, so not a connection we count.