BA 272 then BA 802 at Heathrow
San Diego → London → Reykjavík
Timetable, London time
12:40BA 272 from San Diego at the gate
11:45BA 802 to Reykjavík leaves the gate
23 h 05 apart on the timetable, overnight
BA 802 leaves 23 h 05 after BA 272 arrives on the timetable: more than half a day, so not a connection we count.