The board shall have the authority to allocate racing weeks to an applicant or applicants pursuant to the provisions of this article and Article 6.5 (commencing with Section 19540) and to specify such racing days, dates, and hours for horse racing meetings as will be in the public interest, and will subserve the purposes of this chapter. The decision of the board as to such racing days, dates, and hours shall be subject to change, limitation or restriction only by the board. No municipality or county shall adopt or enforce any ordinance or regulation which has or may have the effect of directly or indirectly regulating, limiting or restricting the racing days and dates of horse racing meetings.