UA 3917 then TP 4392 at San Francisco
Los Angeles → San Francisco → Boston
Timetable, San Francisco time
19:00UA 3917 from Los Angeles at the gate
10:44TP 4392 to Boston leaves the gate
15 h 44 apart on the timetable, overnight
TP 4392 leaves 15 h 44 after UA 3917 arrives on the timetable: more than half a day, so not a connection we count.