BA 673 then SK 1508 at Heathrow
Thessaloniki → London → Copenhagen
Timetable, London time
21:45BA 673 from Thessaloniki at the gate
19:30SK 1508 to Copenhagen leaves the gate
21 h 45 apart on the timetable, overnight
SK 1508 leaves 21 h 45 after BA 673 arrives on the timetable: more than half a day, so not a connection we count.