UA 870 then UA 3912 at San Francisco
Sydney → San Francisco → Houston
Timetable, San Francisco time
06:25UA 870 from Sydney at the gatealso AV 2191, LX 3159, VA 8004, LH 8937, NZ 9870
23:00UA 3912 to Houston leaves the gate
16 h 35 apart on the timetable
UA 3912 leaves 16 h 35 after UA 870 arrives on the timetable: more than half a day, so not a connection we count.