AC 854 then BA 352 at Heathrow
Toronto → London → Nice
Timetable, London time
06:30AC 854 from Toronto at the gate
19:55BA 352 to Nice leaves the gate
13 h 25 apart on the timetable
BA 352 leaves 13 h 25 after AC 854 arrives on the timetable: more than half a day, so not a connection we count.