DY 3659 then BA 817 at Copenhagen
Barcelona → Copenhagen → London Heathrow
Timetable, Copenhagen time
23:45DY 3659 from Barcelona at the gate
21:30BA 817 to London Heathrow leaves the gate
21 h 45 apart on the timetable, overnight
BA 817 leaves 21 h 45 after DY 3659 arrives on the timetable: more than half a day, so not a connection we count.