UA 1883 then DL 9960 at San Francisco
Houston → San Francisco → Seattle
Timetable, San Francisco time
07:28UA 1883 from Houston at the gatealso EK 6028, NZ 9216
11:15DL 9960 to Seattle leaves the gate
3 h 47 apart on the timetable
The last days
UA 1883 and DL 9960 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.