Patriots' Day is a state holiday in Massachusetts and Maine, officially observed on the third Monday of April. It commemorates the anniversary of the Battles of Lexington and Concord, which took place on April 19, 1775, and marked the first armed conflicts of the American Revolutionary War.
Although the historical events occurred on a fixed date, the modern observance was adjusted to create a three-day weekend. In 1969, Massachusetts state law moved the holiday from the fixed date of April 19th to the third Monday of the month. In Boston, the day is synonymous with the annual Boston Marathon. Since 1897, the world-renowned race has been held on Patriots' Day, attracting global participants and spectators and adding a major contemporary athletic event to the historical commemoration.
Therefore, the specific calendar date for Patriots' Day changes each year, but it is always the third Monday in April. This scheduling ensures the holiday is part of a long weekend that includes historical reenactments, parades, and the marathon, making it a unique and significant observance in the region.