DL 2804 then UA 769 at O'Hare
Boston → Chicago → Barcelona
Timetable, Chicago time
21:51DL 2804 from Boston at the gate
21:50UA 769 to Barcelona leaves the gate
23 h 59 apart on the timetable, overnight
UA 769 leaves 23 h 59 after DL 2804 arrives on the timetable: more than half a day, so not a connection we count.