UA 648 then AV 2354 at San Francisco
Newark → San Francisco → Denver
Timetable, San Francisco time
09:30UA 648 from Newark at the gatealso TP 8490, VA 8516, NZ 9121
05:00AV 2354 to Denver leaves the gate
19 h 30 apart on the timetable, overnight
AV 2354 leaves 19 h 30 after UA 648 arrives on the timetable: more than half a day, so not a connection we count.