S.C. Code Ann. § 7-13-355: Time for submitting question to election commission for submission as referendum to electors.

No question may be submitted to the qualified electors in a referendum held at the time of a general election unless the question is submitted to the appropriate election commission to be placed on the ballot no later than 12:00 noon on August fifteenth or, if August fifteenth falls on Saturday or Sunday, not later than 12:00 noon on the following business day.