S.C. Code Ann. § 58-27-2120

The order shall take effect and become operative twenty days after the service thereof, unless otherwise provided, and shall continue in force either for a period which may be designated therein or until changed or revoked by the Commission. If an order cannot, in the judgment of the Commission, be complied with within twenty days, the Commission may grant and prescribe such additional time as in its judgment is reasonably necessary to comply with the order and may, on application and for good cause shown, extend the time for compliance fixed in its order.