BA 825 then BA 756 at Heathrow
Dublin → London → Basel
Timetable, London time
10:20BA 825 from Dublin at the gate
09:25BA 756 to Basel leaves the gate
23 h 05 apart on the timetable, overnight
BA 756 leaves 23 h 05 after BA 825 arrives on the timetable: more than half a day, so not a connection we count.