Cal. PCC § 10306

(a) Whenever a contract under this article is not to be awarded to the lowest bidder, the bidder shall be notified 24 hours prior to awarding the contract to another bidder. Upon written request by any bidder who has submitted a bid, notice of the proposed award shall be posted in a public place specified in the solicitation document by the awarding department, that may include an electronic location or internet website, at least 24 hours prior to awarding the contract. If prior to making the award, any bidder who has submitted a bid that is subject to protest files a protest with the department against the awarding of the contract on the ground that they are the lowest responsible bidder meeting specifications, the contract shall not be awarded until either the protest has been withdrawn or the department has made a final decision as to the action to be taken relative to the protest. In computing the 24-hour periods provided for in this section, Saturdays, Sundays, and legal holidays shall be excluded.

(b) Within 10 days after filing a protest, the protesting bidder shall file with the department a full and complete written statement specifying in detail the ground of the protest and the facts in support thereof.