FB 851 then BA 1312 at Heathrow
Sofia → London → Aberdeen
Timetable, London time
16:45FB 851 from Sofia at the gate
14:20BA 1312 to Aberdeen leaves the gate
21 h 35 apart on the timetable, overnight
BA 1312 leaves 21 h 35 after FB 851 arrives on the timetable: more than half a day, so not a connection we count.