SQ 322 then BA 1458 at Heathrow
Singapore → London → Edinburgh
Timetable, London time
05:55SQ 322 from Singapore at the gate
18:10BA 1458 to Edinburgh leaves the gate
12 h 15 apart on the timetable
BA 1458 leaves 12 h 15 after SQ 322 arrives on the timetable: more than half a day, so not a connection we count.