UA 3875 then UA 1593 at San Francisco
IAB → San Francisco → Houston
Timetable, San Francisco time
01:46UA 3875 from IAB at the gate
23:15UA 1593 to Houston leaves the gatealso EK 6028, NZ 9192
21 h 29 apart on the timetable
UA 1593 leaves 21 h 29 after UA 3875 arrives on the timetable: more than half a day, so not a connection we count.