BA 493 then BA 11 at Heathrow
Gibraltar → London → Singapore
Timetable, London time
19:30BA 493 from Gibraltar at the gate
18:45BA 11 to Singapore leaves the gate
23 h 15 apart on the timetable, overnight
BA 11 leaves 23 h 15 after BA 493 arrives on the timetable: more than half a day, so not a connection we count.