BA 547 then BA 632 at Heathrow
Bologna → London → Athens
Timetable, London time
09:05BA 547 from Bologna at the gate
08:15BA 632 to Athens leaves the gate
23 h 10 apart on the timetable, overnight
BA 632 leaves 23 h 10 after BA 547 arrives on the timetable: more than half a day, so not a connection we count.