D.C. celebrates the Compensated Emancipation Act, which was signed by Abraham Lincoln on April 16, 1862.
The holiday, observed on Friday if April 16 falls on a Saturday, is meant to celebrate the day Lincoln signed the bill that freed 3,000 slaves in the nation's capital, which is a different event from the national Emancipation Proclamation, The Miami Herald explained.
That pushes everyone's tax deadline to April 18 this year.
That amounts to a blessing for some but a headache for others.
"Now it kills my weekend. I'll be working Saturday and Sunday," certified public accountant Michael Fish of Miami told the newspaper.