Cal. Gov't Code § 6701

(a) If January 1, February 12, March 31, July 4, September 9, November 11, or December 25 falls upon a Sunday, the Monday following is a holiday.
(b) If November 11 falls upon a Saturday, the preceding Friday is a holiday.
(c) If March 31 falls upon a Tuesday, Wednesday, or Thursday, the Legislature may observe the holiday on one of the following:
1. (1) The preceding Friday.
2. (2) The preceding Monday.
3. (3) The following Friday.
(d) If any holiday designated in Section 6700 falls on a Saturday, the board of supervisors of any county may by ordinance or resolution provide that an alternate day shall be a holiday for the employees of the county, except those employees of the county working as court attachés.