law: The Joint-stock Companies Act, 1857
  XXII. Power to close Register.-
  The Company may, upon giving notice by advertisement in some newspapers circulating in that part of the said territories in which the registered Office of the Company is situate, close the Register of shareholders for any time or times not exceeding on the whole twenty-one days in each year: and the period, during which the books are closed, shall not be reckoned as part of the time within which a transfer is to be registered.