A3 629 then A3 608 at Athens
Luxembourg → Athens → London Heathrow
Timetable, Athens time
21:55A3 629 from Luxembourg at the gate
19:10A3 608 to London Heathrow leaves the gate
21 h 15 apart on the timetable, overnight
A3 608 leaves 21 h 15 after A3 629 arrives on the timetable: more than half a day, so not a connection we count.