BA 1453 then BA 600 at Heathrow
Edinburgh → London → Venezia
Timetable, London time
18:55BA 1453 from Edinburgh at the gate
18:10BA 600 to Venezia leaves the gate
23 h 15 apart on the timetable, overnight
BA 600 leaves 23 h 15 after BA 1453 arrives on the timetable: more than half a day, so not a connection we count.