The term functions as a proper noun phrase. In this construction, "Patriot's Day" is the core proper noun, naming a specific holiday, and "Massachusetts" acts as an adjectival noun, modifying the holiday to specify its geographic context. The entire phrase identifies a unique civic observance.
This state holiday is observed on the third Monday of April in Massachusetts to commemorate the opening engagements of the American Revolutionary War. The events it marks occurred on April 19, 1775, specifically the Battles of Lexington and Concord and the beginning of the Siege of Boston. Public observances often include parades, historical reenactments, and the running of the Boston Marathon, which has been held on the holiday since 1897.
The practical application of understanding this term is to distinguish it from the national observance known as Patriot Day, which occurs on September 11th to remember the victims of the 2001 terrorist attacks. The Massachusetts holiday is a regional commemoration tied directly to the state's foundational role in American independence and carries a distinct historical and cultural significance.
