The Japanese term for "September 11th" is (, kugatsu jichinichi). The primary part of speech for this term is a noun (, meishi). It functions as a proper noun that specifically names a calendar date.
In Japanese grammar, is further classified as a temporal noun or adverbial noun (, jikan meishi). This is a specific sub-category of nouns that refers to a point in time. While it is fundamentally a noun, it has the distinct characteristic of being able to function adverbially within a sentence to indicate when an action takes place, often with the addition of the particle (ni), but sometimes without.
Understanding that is a temporal noun is critical for correct sentence construction. This classification dictates its syntactic role; it can serve as the subject of a sentence (e.g., "September 11th is a day of remembrance"), an object, or an adverbial phrase modifying a verb (e.g., "The event occurred on September 11th"). This dual noun/adverbial function is a key grammatical concept that governs how the date is integrated into Japanese text.
