A3 629 then A3 604 at Athens
Luxembourg → Athens → London Heathrow
Timetable, Athens time
21:55A3 629 from Luxembourg at the gate
15:55A3 604 to London Heathrow leaves the gate
18 h apart on the timetable, overnight
A3 604 leaves 18 h after A3 629 arrives on the timetable: more than half a day, so not a connection we count.