A3 293 then BA 637 at Athens
Kefalonia → Athens → London Heathrow
Timetable, Athens time
21:05A3 293 from Kefalonia at the gate
19:40BA 637 to London Heathrow leaves the gate
22 h 35 apart on the timetable, overnight
BA 637 leaves 22 h 35 after A3 293 arrives on the timetable: more than half a day, so not a connection we count.