Patriots' Day is not observed in September. The holiday occurs annually on the third Monday in April. The association with September likely stems from a confusion with a similarly named but distinct observance, Patriot Day, which is held on September 11th.
The keyword phrase "Patriots' Day" functions as a proper noun, designating a specific state holiday in Massachusetts, Maine, and Wisconsin. This holiday commemorates the anniversary of the Battles of Lexington and Concord on April 19, 1775, the first armed conflicts of the American Revolutionary War. In contrast, "Patriot Day" is also a proper noun, but it refers to the national day of remembrance for the victims of the September 11, 2001 terrorist attacks. The phonetic similarity between the two names is the primary source of the date-related confusion.
Therefore, the core of the analysis rests on distinguishing between these two proper nouns. "Patriots' Day" refers to the Revolutionary War commemoration in April, while the event in September is correctly named "Patriot Day." Recognizing "Patriots' Day" as a proper noun is crucial to understanding its specific historical context and fixed observance date, which is separate from any events in September.
