BA 206 then BA 546 at Heathrow
Miami → London → Bologna
Timetable, London time
06:45BA 206 from Miami at the gate
19:25BA 546 to Bologna leaves the gate
12 h 40 apart on the timetable
BA 546 leaves 12 h 40 after BA 206 arrives on the timetable: more than half a day, so not a connection we count.