UA 423 then DL 5845 at Philadelphia
Chicago O'Hare → Philadelphia → Boston
Timetable, Philadelphia time
09:52UA 423 from Chicago O'Hare at the gate
09:00DL 5845 to Boston leaves the gate
23 h 08 apart on the timetable, overnight
DL 5845 leaves 23 h 08 after UA 423 arrives on the timetable: more than half a day, so not a connection we count.