UA 367 then UA 412 at San Francisco
Washington → San Francisco → Mexico City
Timetable, San Francisco time
01:29UA 367 from Washington at the gatealso LH 7530, VA 8388, NZ 9181
22:48UA 412 to Mexico City leaves the gatealso AC 5025
21 h 19 apart on the timetable
UA 412 leaves 21 h 19 after UA 367 arrives on the timetable: more than half a day, so not a connection we count.