SK 531 then BA 558 at Heathrow
Stockholm → London → Rome
Timetable, London time
12:55SK 531 from Stockholm at the gate
11:40BA 558 to Rome leaves the gate
22 h 45 apart on the timetable, overnight
BA 558 leaves 22 h 45 after SK 531 arrives on the timetable: more than half a day, so not a connection we count.