UA 571 then UA 1 at San Francisco
Atlanta → San Francisco → Singapore
Timetable, San Francisco time
09:29UA 571 from Atlanta at the gatealso CA 7243, VA 8403, NZ 9005
22:40UA 1 to Singapore leaves the gate
13 h 11 apart on the timetable
UA 1 leaves 13 h 11 after UA 571 arrives on the timetable: more than half a day, so not a connection we count.