UA 3909 then CA 7407 at San Francisco
Cancún → San Francisco → Austin
Timetable, San Francisco time
15:10UA 3909 from Cancún at the gate
12:06CA 7407 to Austin leaves the gate
20 h 56 apart on the timetable, overnight
CA 7407 leaves 20 h 56 after UA 3909 arrives on the timetable: more than half a day, so not a connection we count.