Tax Deadline April 18 Thanks to ... Abraham Lincoln? DC Emancipation Day pushes filing deadline 3 days By Rob Quinn, Newser Staff Posted Jan 5, 2011 4:24 AM CST 7 comments Comments Anise Kenkins rattles chains in honor of DC Emancipation Day, commemorating the freeing of slaves, during a march and rally in Washington, Monday April 16, 2007. (AP Photo/Jacquelyn Martin) (Newser) – America's taxpayers have an extra three days to procrastinate this year, thanks to a holiday only celebrated in the nation's capital, AP reports. Abraham Lincoln freed the District of Columbia's slaves on April 16, 1862—eight months before the Emancipation Proclamation—and since this year's DC Emancipation Day falls on a Saturday, the district workers get Friday, April 15 off. Tax returns therefore won't be due until midnight on the 18th.