QF 73 then UA 1668 at San Francisco
Sydney → San Francisco → San Diego
Timetable, San Francisco time
15:55QF 73 from Sydney at the gatealso AS 5001, AA 7397
13:50UA 1668 to San Diego leaves the gatealso AC 4559, NH 7300, VA 8431
21 h 55 apart on the timetable, overnight
UA 1668 leaves 21 h 55 after QF 73 arrives on the timetable: more than half a day, so not a connection we count.