S.C. Code Ann. § 53-5-30

Whenever any of the legal holidays mentioned in Section 53-5-10 shall fall upon Sunday the Monday next following shall be deemed a public holiday and whenever any of the holidays mentioned in such section shall fall upon Saturday the Friday next preceding shall be deemed a public holiday for all of the purposes aforesaid. In such cases all bills of exchange, checks and promissory notes which would otherwise be presentable for acceptance or payment on any such Monday or Friday shall be deemed to be presentable for acceptance or payment on the secular or business day next succeeding the holiday.