AA 2074 then DL 1655 at Boston
Chicago O'Hare → Boston → San Francisco
Timetable, Boston time
17:08AA 2074 from Chicago O'Hare at the gate
16:50DL 1655 to San Francisco leaves the gate
23 h 42 apart on the timetable, overnight
DL 1655 leaves 23 h 42 after AA 2074 arrives on the timetable: more than half a day, so not a connection we count.