The core component of the keyword phrase, "Patriots Day," is a proper noun. While the full phrase "patriots day each year" often functions as an adverbial phrase modifying a verb in a sentence, the central subject and the grammatical foundation for the article's topic is the noun itself.
A detailed grammatical analysis separates the phrase into its constituent parts. "Patriots Day" names a specific, unique holiday, which classifies it as a proper noun. The secondary part, "each year," is an adverbial phrase of time and frequency that specifies when or how often an action related to the holiday occurs. For example, in the sentence, "The city holds a parade on Patriots Day each year," the phrase modifies the verb "holds" by providing temporal context.
Therefore, for the purpose of an article where "Patriots Day" is the main point, the crucial part of speech to identify is the noun. This establishes the holiday as the primary subjecta specific entity with its own history, traditions, and significance. The adverbial aspect ("each year") is a key attribute describing the holiday's annual recurrence but is secondary to the subject's core identity as a noun.
