OO 9909 then UA 3484 at O'Hare
Waterloo → Chicago → Pittsburgh
Timetable, Chicago time
16:47OO 9909 from Waterloo at the gate
15:45UA 3484 to Pittsburgh leaves the gate
22 h 58 apart on the timetable, overnight
UA 3484 leaves 22 h 58 after OO 9909 arrives on the timetable: more than half a day, so not a connection we count.