New Tax Filing Deadline For Income Tax Returns - April 17, 2012
Since April 15, 2012 falls on a Sunday, and Emancipation Day in DC (a DC-only holiday) is observed on Monday April 16th, the official filing deadline will move to the next business day which is Tuesday, April 17th.  The IRS only moves due dates for national and DC holidays.

The South Carolina Department of Revenue will honor the federal due date, but will not change the forms to reflect April 17th as the deadline. The April 17th deadline applies to any income tax return or payment normally due on April 15th.  It also applies to the deadline for requesting a tax-filing extension.