Ashley Lowrimore For The Lancaster News Make that list and check it twice. No, not for Santa – for tax-free back-to-school shopping during the annual S.C. Sales-Tax-Free Weekend. Starting at 12:01 a.m. Friday, Aug. 4, and continuing through Sunday, Aug. 6, book bags, clothing, pencils, paper and other school supplies are exempt from the 6 percent state sales tax. The S.C.