AC 4121 then UA 2603 at San Francisco
Ontario → San Francisco → Salt Lake City
Timetable, San Francisco time
17:50AC 4121 from Ontario at the gatealso UA 5483
12:28UA 2603 to Salt Lake City leaves the gate
18 h 38 apart on the timetable, overnight
UA 2603 leaves 18 h 38 after AC 4121 arrives on the timetable: more than half a day, so not a connection we count.