OO 9909 then AA 3720 at O'Hare
Waterloo → Chicago → Manchester
Timetable, Chicago time
16:47OO 9909 from Waterloo at the gate
13:10AA 3720 to Manchester leaves the gate
20 h 23 apart on the timetable, overnight
AA 3720 leaves 20 h 23 after OO 9909 arrives on the timetable: more than half a day, so not a connection we count.