UA 1780 then DL 2197 at San Francisco
Dallas-Fort Worth → San Francisco → Los Angeles
Timetable, San Francisco time
17:17UA 1780 from Dallas-Fort Worth at the gatealso AC 3148, VA 8579, NZ 9092
20:50DL 2197 to Los Angeles leaves the gatealso VS 4102, AF 5810
3 h 33 apart on the timetable
The last days
UA 1780 and DL 2197 weren’t both flown 15 min to 12 h apart in the last 21 days.
Statistics from past flights, not live flight information. Always check times and your connection with your airline, and don’t base travel or booking decisions on these numbers.