The term functions as a proper noun phrase. As a single grammatical unit, it names a specific, unique entity: the official day of remembrance in the United States for the events that occurred on a particular historical date. Its role is to identify, not to describe or show action.
This classification is derived from its components. "Patriot Day" is itself a proper noun, the official title of the observance. The following date, "September 11, 2001," is a noun phrase acting as an appositive, a grammatical element that renames or specifies the preceding noun. The date clarifies and inextricably links the observance to the historical event it commemorates. Combined, they form a more specific and complete proper noun phrase that refers to a singular concept.
Understanding this grammatical function is crucial for structuring the article. As a proper noun phrase, the term can serve as the primary subject of sentences, paragraphs, and the article as a whole. It acts as a central anchor to which verbs, clauses, and descriptive information can be attached. For example, the article can be structured to analyze what this designation is, what it represents, or how it was established, with the noun phrase consistently functioning as the subject of these inquiries.
