What day of the week is this going to happen on? exact times? 6am to 2pm or 1pm to 9pm?
Where are you flying in from?
Which airline are you flying in and out on?
Will this be one ticket or two?
What nationality are you and what travel document will you be using?

All these will add to time you will spend at YVR upon arrival and before departure. Flying to SFO will require US CBP entry pre-cearing at YVR which adds to yu time.