N.C. Gen. Stat. § 105-563

The Board of Trustees may, by resolution, repeal the levy of the tax under this Article or decrease the amount of the tax, under the same procedures and subject to the same limitations as provided in G.S. 105-561. A tax repeal or a tax decrease becomes effective on the date set by the board of trustees in the resolution repealing or decreasing the tax. The effective date must be on the first day of a month and may not be earlier than the first day of the sixth calendar month after the board of trustees adopts the resolution. Repeal or decrease of a tax levied under this Article does not affect the rights or liabilities of an Authority, a taxpayer, or another person arising before the repeal or decrease.