For the period beginning September 1, 1987, and ending September 30, 1987, the affidavit is due and the tax shall be paid by October 20, 1987.
Each telecommunication company shall be allowed a credit against the gross receipts tax imposed for the period for one-twelfth (1/12) of the amount of personal property tax paid on the tax year 1988 return due by July 31, 1987.
D.C. Mun. Regs. tit. 9, r. 9-3503