BA 276 then BA 802 at Heathrow
Hyderabad → London → Reykjavík
Timetable, London time
13:00BA 276 from Hyderabad at the gate
11:45BA 802 to Reykjavík leaves the gate
22 h 45 apart on the timetable, overnight
BA 802 leaves 22 h 45 after BA 276 arrives on the timetable: more than half a day, so not a connection we count.