California Code, Civil Code - CIV § 9404

The public entity shall serve on the claimant a copy of the direct contractor's affidavit, together with a notice stating that the public entity will release the funds withheld, or the portion of the funds demanded, unless the claimant serves on the public entity a counteraffidavit on or before the time stated in the notice. The time stated in the notice shall be not less than 10 days nor more than 20 days after service on the claimant of the copy of the affidavit. The notice shall comply with the requirements of Chapter 2 (commencing with Section 8100) of Title 1.