Like every other California court, the 4/3 will be closed on the 3rd Wednesday of every month to accomodate mandatory furloughs. The clerk's office will be closed, so don't try to file anything. And no oral argument will be held that day, though the 4/3 will otherwise continue to schedule oral argument for the 3rd week of every month.
In the 4/3 and elsewhere, the 3rd Wednesday will be treated as a court holiday. New Cal. Gov't Code section 68106 (b)(1) provides: "(1) If the Judicial Council has provided for the closure of courts pursuant to this section, the day so designated shall be treated as a holiday for purposes of performing any act requiring the transaction of judicial business ...." (Thanks to Ben Shatz for the pointer)