UA 2005 then UA 5901 at O'Hare
Pensacola → Chicago → St Louis
Timetable, Chicago time
17:00UA 2005 from Pensacola at the gate
15:20UA 5901 to St Louis leaves the gate
22 h 20 apart on the timetable, overnight
UA 5901 leaves 22 h 20 after UA 2005 arrives on the timetable: more than half a day, so not a connection we count.