BA 591 then BA 802 at Heathrow
Venezia → London → Reykjavík
Timetable, London time
12:10BA 591 from Venezia at the gate
11:45BA 802 to Reykjavík leaves the gate
23 h 35 apart on the timetable, overnight
BA 802 leaves 23 h 35 after BA 591 arrives on the timetable: more than half a day, so not a connection we count.