UA 4072 then DL 5845 at Philadelphia
Washington → Philadelphia → Boston
Timetable, Philadelphia time
09:49UA 4072 from Washington at the gate
09:00DL 5845 to Boston leaves the gate
23 h 11 apart on the timetable, overnight
DL 5845 leaves 23 h 11 after UA 4072 arrives on the timetable: more than half a day, so not a connection we count.