The phrase functions as an adverbial phrase of time. Its primary grammatical role is to modify a verb, an adjective, or another adverb by specifying a precise point in time, answering the question "when?". As a unit, it provides a temporal context for the main clause of a sentence.
This construction is composed of several grammatical elements working in concert. "90 days" is a noun phrase specifying a duration. It modifies the prepositional phrase "after september 11 2025." The preposition "after" establishes a relationship between the duration and a specific point in time, which is the noun phrase "september 11 2025." The entire phrase operates adverbially to locate an event or state in time relative to a fixed date.
Determining this grammatical function is critical because it establishes that the article's subject is not the date itself, but an action, event, or condition that occurs at that specific temporal juncture. The phrase serves as a temporal anchor, signaling that the core information will concern what happens, or is the case, on that particular day, which is December 10, 2025.
