BA 581 then AA 81 at Heathrow
Milan → London → Dallas-Fort Worth
Timetable, London time
13:55BA 581 from Milan at the gate
13:50AA 81 to Dallas-Fort Worth leaves the gate
23 h 55 apart on the timetable, overnight
AA 81 leaves 23 h 55 after BA 581 arrives on the timetable: more than half a day, so not a connection we count.