UA 1591 then UA 643 at San Francisco
San Antonio → San Francisco → Santa Ana
Timetable, San Francisco time
11:02UA 1591 from San Antonio at the gatealso NZ 2372, UA 2490, AC 4201, EK 6003
10:32UA 643 to Santa Ana leaves the gatealso AC 4518, VA 8495, NZ 9717
23 h 30 apart on the timetable, overnight
UA 643 leaves 23 h 30 after UA 1591 arrives on the timetable: more than half a day, so not a connection we count.