AC 4229 then UA 8153 at San Francisco
Boise → San Francisco → Washington
Timetable, San Francisco time
13:00AC 4229 from Boise at the gatealso UA 4733, EK 6020, NZ 9392
22:53UA 8153 to Washington leaves the gate
9 h 53 apart on the timetable
The last days
AC 4229 and UA 8153 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.