UA 506 then UA 785 at San Francisco
Raleigh-Durham → San Francisco → Washington
Timetable, San Francisco time
11:19UA 506 from Raleigh-Durham at the gatealso VA 8587, NZ 9559
06:15UA 785 to Washington leaves the gatealso AZ 4408, NZ 9160
18 h 56 apart on the timetable, overnight
UA 785 leaves 18 h 56 after UA 506 arrives on the timetable: more than half a day, so not a connection we count.