AC 4121 then AV 2354 at San Francisco
Ontario → San Francisco → Denver
Timetable, San Francisco time
10:55AC 4121 from Ontario at the gate
05:00AV 2354 to Denver leaves the gate
18 h 05 apart on the timetable, overnight
AV 2354 leaves 18 h 05 after AC 4121 arrives on the timetable: more than half a day, so not a connection we count.