About National Tax Day
In the United States, Tax Day is the day on which individual income tax returns are due to be submitted to the federal government. Since 1955, Tax Day has typically fallen on or just after April 15. When a tax deadline falls on a Saturday, Sunday or holiday, it's pushed back to the next available business day.
Emancipation Day is observed in the District of Columbia on April 16th. The holiday honors the end of slavery in Washington, D.C. If April 16th is on a Saturday, the holiday falls on April 15th, and if April 16th is on a Sunday, then Monday April 17th is a holiday.
Since Emancipation Day is a legal holiday in D.C., the IRS can't require tax returns to be filed that day. The next business day becomes the new federal income tax filing deadline for most people.
Tax Day was first introduced in 1913, when the Sixteenth Amendment was ratified.