BA 1479 then AA 9600 at Heathrow
Glasgow → London → Chicago
Timetable, London time
13:15BA 1479 from Glasgow at the gate
13:00AA 9600 to Chicago leaves the gate
23 h 45 apart on the timetable, overnight
AA 9600 leaves 23 h 45 after BA 1479 arrives on the timetable: more than half a day, so not a connection we count.