BA 349 then SK 528 at Heathrow
Nice → London → Stockholm
Timetable, London time
21:05BA 349 from Nice at the gate
18:05SK 528 to Stockholm leaves the gate
21 h apart on the timetable, overnight
SK 528 leaves 21 h after BA 349 arrives on the timetable: more than half a day, so not a connection we count.