California Code, Code of Civil Procedure - CCP § 484.350

(a) If the defendant claims that the property described in the plaintiff's application, or a portion of such property, is exempt from attachment, the defendant may claim the exemption as provided in this section. If the defendant fails to make a claim with respect to personal property, or makes a claim with respect to real or personal property but fails to prove that the property is exempt, the defendant may not later claim the exemption except as provided in Section 482.100.

(b) The claim of exemption shall:

(c) The claim of exemption shall be accompanied by an affidavit supporting any factual issues raised by the claim and points and authorities supporting any legal issues raised.

(d) The claim of exemption, together with any supporting affidavit and points and authorities, shall be filed and served on the plaintiff not less than five court days before the date set for the hearing.