The Mayor of the District of Columbia is authorized, after a public hearing, to fix and change from time to time the period for which any license, certificate, or registration authorized by any section set forth in § 1-321.02 may be issued. Upon change of a license, certificate or registration period, the fee for any such license, certificate, or registration shall be prorated on the basis of the time covered.
D.C. Code § 1-321.04