Cal. Code of Civil Procedure § 1207

Within five days after receiving a copy of the statement provided for in the next preceding section, either the plaintiff or the defendant in the action in which the writ issued may file with the officer a sworn statement denying that any part of such claim is due for services rendered within ninety days next preceding the levy of the writ, or denying that any part of such claim, beyond a sum specified, is so due. Such sworn statement can not be made on information and belief unless the party swearing to same has actual information and belief that the wage claim, or the portion thereof that is contested, is not justly due, and in such case the nature and source of the information must be given. If a part of the claim is admitted to be due, and the claimant nevertheless files a petition for hearing and the court does not allow more than the amount so admitted, he can not recover costs but the costs must be adjudged against him, and the amount thereof deducted from the sum found due him.