The assessment of taxes herein made and the returns required therefor shall be for the tax year ending on the thirty-first day of December. If the taxpayer, in exercising a privilege taxable under this article, keeps the books reflecting the same on a basis other than the calendar year, he may, with the assent of the Mayor, make his annual returns and pay taxes for the year covering his accounting period, as shown by the method of keeping his books.
(1977 Code 5-418.)