EW 2520 then BA 495 at Barcelona
Stuttgart → Barcelona → London Heathrow
Timetable, Barcelona time
08:35EW 2520 from Stuttgart at the gate
20:50BA 495 to London Heathrow leaves the gate
12 h 15 apart on the timetable
BA 495 leaves 12 h 15 after EW 2520 arrives on the timetable: more than half a day, so not a connection we count.