DL 16 then BA 774 at Heathrow
Detroit → London → Oslo
Timetable, London time
07:45DL 16 from Detroit at the gate
20:20BA 774 to Oslo leaves the gate
12 h 35 apart on the timetable
BA 774 leaves 12 h 35 after DL 16 arrives on the timetable: more than half a day, so not a connection we count.