BA 775 then BA 478 at Heathrow
Oslo → London → Barcelona
Timetable, London time
08:30BA 775 from Oslo at the gate
08:20BA 478 to Barcelona leaves the gate
23 h 50 apart on the timetable, overnight
BA 478 leaves 23 h 50 after BA 775 arrives on the timetable: more than half a day, so not a connection we count.