AV 2347 then UA 3883 at San Francisco
Burbank → San Francisco → Boston
Timetable, San Francisco time
11:18AV 2347 from Burbank at the gate
23:40UA 3883 to Boston leaves the gate
12 h 22 apart on the timetable
UA 3883 leaves 12 h 22 after AV 2347 arrives on the timetable: more than half a day, so not a connection we count.