DL 2804 then UA 2106 at O'Hare
Boston → Chicago → San Francisco
Timetable, Chicago time
22:36DL 2804 from Boston at the gate
21:57UA 2106 to San Francisco leaves the gate
23 h 21 apart on the timetable, overnight
UA 2106 leaves 23 h 21 after DL 2804 arrives on the timetable: more than half a day, so not a connection we count.