AC 4121 then UA 2390 at San Francisco
Ontario → San Francisco → Austin
Timetable, San Francisco time
17:50AC 4121 from Ontario at the gatealso UA 5483
17:20UA 2390 to Austin leaves the gatealso AC 3276
23 h 30 apart on the timetable, overnight
UA 2390 leaves 23 h 30 after AC 4121 arrives on the timetable: more than half a day, so not a connection we count.