EC 7152 then BA 479 at Barcelona
Milan → Barcelona → London Heathrow
Timetable, Barcelona time
16:10EC 7152 from Milan at the gate
13:35BA 479 to London Heathrow leaves the gate
21 h 25 apart on the timetable, overnight
BA 479 leaves 21 h 25 after EC 7152 arrives on the timetable: more than half a day, so not a connection we count.