UA 3903 then UA 1609 at Houston
Newark → Houston → San Francisco
Timetable, Houston time
09:05UA 3903 from Newark at the gate
21:45UA 1609 to San Francisco leaves the gate
12 h 40 apart on the timetable
UA 1609 leaves 12 h 40 after UA 3903 arrives on the timetable: more than half a day, so not a connection we count.