BA 677 then BA 1338 at Heathrow
Istanbul → London → Newcastle
Timetable, London time
16:40BA 677 from Istanbul at the gate
16:05BA 1338 to Newcastle leaves the gate
23 h 25 apart on the timetable, overnight
BA 1338 leaves 23 h 25 after BA 677 arrives on the timetable: more than half a day, so not a connection we count.