UA 920 then BA 592 at Heathrow
Chicago → London → Venezia
Timetable, London time
07:55UA 920 from Chicago at the gate
07:30BA 592 to Venezia leaves the gate
23 h 35 apart on the timetable, overnight
BA 592 leaves 23 h 35 after UA 920 arrives on the timetable: more than half a day, so not a connection we count.