AC 4121 then UA 1593 at San Francisco
Ontario → San Francisco → Houston
Timetable, San Francisco time
10:55AC 4121 from Ontario at the gate
23:15UA 1593 to Houston leaves the gatealso EK 6028, NZ 9192
12 h 20 apart on the timetable
UA 1593 leaves 12 h 20 after AC 4121 arrives on the timetable: more than half a day, so not a connection we count.