BA 439 then BA 588 at Heathrow
Amsterdam → London → Milan
Timetable, London time
16:25BA 439 from Amsterdam at the gate
15:20BA 588 to Milan leaves the gate
22 h 55 apart on the timetable, overnight
BA 588 leaves 22 h 55 after BA 439 arrives on the timetable: more than half a day, so not a connection we count.