VA 8311 then UA 2837 at San Francisco
Boston → San Francisco → Washington
Timetable, San Francisco time
10:59VA 8311 from Boston at the gate
23:20UA 2837 to Washington leaves the gate
12 h 21 apart on the timetable
UA 2837 leaves 12 h 21 after VA 8311 arrives on the timetable: more than half a day, so not a connection we count.