BA 553 then SK 806 at Heathrow
Rome → London → Oslo
Timetable, London time
16:35BA 553 from Rome at the gate
15:35SK 806 to Oslo leaves the gate
23 h apart on the timetable, overnight
SK 806 leaves 23 h after BA 553 arrives on the timetable: more than half a day, so not a connection we count.