BA 521 then BA 119 at Heathrow
Firenze → London → Bengaluru
Timetable, London time
13:45BA 521 from Firenze at the gate
13:40BA 119 to Bengaluru leaves the gate
23 h 55 apart on the timetable, overnight
BA 119 leaves 23 h 55 after BA 521 arrives on the timetable: more than half a day, so not a connection we count.