N.C. Gen. Stat. § 1-595: Advertisement of public sales.

When a statute or written instrument stipulates that an advertisement of a sale shall be made for any certain number of weeks, a publication once a week for the number of weeks so indicated is a sufficient compliance with the requirement, unless contrary provision is expressly made by the terms of the instrument. (1909, cc. 794, 875; C.S., s. 924.)