UA 574 then UA 785 at San Francisco
Boston → San Francisco → Washington
Timetable, San Francisco time
12:49UA 574 from Boston at the gate
06:15UA 785 to Washington leaves the gatealso AZ 4408, NZ 9160
17 h 26 apart on the timetable, overnight
UA 785 leaves 17 h 26 after UA 574 arrives on the timetable: more than half a day, so not a connection we count.