CI 81 then BA 638 at Heathrow
Taipei → London → Athens
Timetable, London time
16:55CI 81 from Taipei at the gate
16:15BA 638 to Athens leaves the gate
23 h 20 apart on the timetable, overnight
BA 638 leaves 23 h 20 after CI 81 arrives on the timetable: more than half a day, so not a connection we count.