BA 591 then BA 191 at Heathrow
Venezia → London → Austin
Timetable, London time
13:10BA 591 from Venezia at the gate
12:10BA 191 to Austin leaves the gate
23 h apart on the timetable, overnight
BA 191 leaves 23 h after BA 591 arrives on the timetable: more than half a day, so not a connection we count.