BA 551 then QR 8 at Heathrow
Rome → London → Doha
Timetable, London time
15:05BA 551 from Rome at the gate
14:55QR 8 to Doha leaves the gate
23 h 50 apart on the timetable, overnight
QR 8 leaves 23 h 50 after BA 551 arrives on the timetable: more than half a day, so not a connection we count.