BA 12 then SK 528 at Heathrow
Singapore → London → Stockholm
Timetable, London time
05:45BA 12 from Singapore at the gate
18:05SK 528 to Stockholm leaves the gate
12 h 20 apart on the timetable
SK 528 leaves 12 h 20 after BA 12 arrives on the timetable: more than half a day, so not a connection we count.