UA 3752 then QR 2091 at San Francisco
Denver → San Francisco → Santa Ana
Timetable, San Francisco time
13:00UA 3752 from Denver at the gate
09:00QR 2091 to Santa Ana leaves the gate
20 h apart on the timetable, overnight
QR 2091 leaves 20 h after UA 3752 arrives on the timetable: more than half a day, so not a connection we count.