S.C. Code § 12-20-20
2002 Act No. 334, Section 8.E and 2002 Act No. 363, Section 1.F provide as follows:
"This section takes effect upon approval by the Governor and applies for estimated taxes due after 2002."
2016 Act No. 160, Section 4.E, provides as follows:
"E. This SECTION takes effect upon approval by the Governor and first applies to tax years beginning after 2015."