Cal. Civ. Proc. Code § 135

Every full day designated as a holiday by Section 6700 of the Government Code, including that Thursday of November declared by the President to be Thanksgiving Day, is a judicial holiday, except September 9, known as “Admission Day,” and any other day appointed by the President, but not by the Governor, for a public fast, thanksgiving, or holiday. If a judicial holiday falls on a Saturday or a Sunday, the Judicial Council may designate an alternative day for observance of the holiday. Every Saturday and the day after Thanksgiving Day is a judicial holiday. Officers and employees of the courts shall observe only the judicial holidays established pursuant to this section.