Tax Day occasionally falls on Patriots' Day, a civic holiday in the Commonwealth of Massachusetts and state of Maine, or the preceding weekend. When this occurred for some time, the federal tax deadline was extended by a day for the residents of Maine, Maryland, Massachusetts, New Hampshire, New York, Vermont, and the District of Columbia, because the IRS processing center for these areas was located in Andover, Massachusetts and the unionized IRS employees got the day off.[9] In 2011, the Monday, April 18, Tax Day fell on Patriots' Day.