BA 487 then QF 2 at Heathrow
Barcelona → London → Sydney
Timetable, London time
20:35BA 487 from Barcelona at the gate
20:10QF 2 to Sydney leaves the gate
23 h 35 apart on the timetable, overnight
QF 2 leaves 23 h 35 after BA 487 arrives on the timetable: more than half a day, so not a connection we count.