I have a question regarding the use of "before" as an adverb. In the following examples, what word or words does "before" modify? As an adverb, it should modify either a verb, an adjective, or another adverb.
a few days before
the night before
The war had ended a month or so before.
I finished college the year before.
In all of these examples, "before" follows a noun. What word or words does "before" modify? The main verb of the sentence?
Also, what is the function of the noun (or noun phrase) within the sentence in the latter two examples?