UA 2124 then DL 1564 at O'Hare
Houston → Chicago → Seattle (SEA)
Timetable, Chicago time
12:45UA 2124 from Houston at the gate
12:00DL 1564 to Seattle (SEA) leaves the gate
23 h 15 apart on the timetable, overnight
DL 1564 leaves 23 h 15 after UA 2124 arrives on the timetable: more than half a day, so not a connection we count.