The keyword phrase functions as an interrogative clause, with the core subject being the proper noun "Patriots' Day." This holiday is a state-level observance in Massachusetts, officially celebrated on the third Monday in April each year. The specific calendar date therefore varies annually.
This observance commemorates the anniversary of the Battles of Lexington and Concord, which took place on April 19, 1775, marking the start of the American Revolutionary War. The holiday was originally fixed to April 19. A 1969 Massachusetts statute moved the observance to the third Monday of the month, a legislative change consistent with the practice of creating three-day weekends for public holidays.
In contemporary application, the date is most widely known for hosting the Boston Marathon. The world-renowned race is traditionally run on Patriots' Day, leading to the colloquial term "Marathon Monday." This scheduling makes the holiday a significant cultural and athletic event in addition to its historical commemoration.
