In the United States, Tax Day is a colloquial term for the day on which individual income tax returns are due to the federal government. The term may also refer to the same day for states, even where the tax return due date is a different day.
Since 1955, for those living in the United States, Tax Day has typically fallen on April 15. For people who file a U.S. tax return and live outside the United States and Puerto Rico, Tax Day has typically fallen on June 15, because of the two-month automatic extension granted to filers by IRS Publication 54.
Emancipation Day, a holiday in Washington, D.C. that is observed on the weekday closest to April 16, causes special rules to apply: When April 15 falls on a Friday, tax returns are due the following Monday; when April 15 falls on a Saturday or Sunday, tax returns are due the following Tuesday.