UA 1623 then UA 3912 at San Francisco
Sacramento → San Francisco → Houston
Timetable, San Francisco time
07:15UA 1623 from Sacramento at the gatealso AC 4541, VA 8267, NZ 9676
23:00UA 3912 to Houston leaves the gate
15 h 45 apart on the timetable
UA 3912 leaves 15 h 45 after UA 1623 arrives on the timetable: more than half a day, so not a connection we count.