BA 1421 then BA 758 at Heathrow
Inverness → London → Basel
Timetable, London time
12:55BA 1421 from Inverness at the gate
12:10BA 758 to Basel leaves the gate
23 h 15 apart on the timetable, overnight
BA 758 leaves 23 h 15 after BA 1421 arrives on the timetable: more than half a day, so not a connection we count.