"A month passed" or “A month past”? [closed]

I recently wrote the sentence, "I saw the deadline was a month passed," and have confused myself over whether it should be past or passed.

I believe it is passed—perhaps as an adverbial past participle?—because I am not referring to the past month, specifically, but that a month has passed. Also, if I take out "a month" I am left with, "I saw the deadline was passed" which I believe is more the meaning I seek (even if awkward) than "I saw the deadline was past". I am not confident, though.

Potentially relevant previous questions:

  1. "Past due" or "passed due"
  2. date has already passed OR date has already past? — This question, though, is simply a matter of the poster not knowing the meanings of past and passed, and was closed.

It seems to me that the sentence is incorrect with passed. It would say that the deadline was a month passed, but the deadline does not equate in any obvious way to a month passed. It does seem, however, that one could say that the deadline was a month past, if one considers a month past equivalent to a month ago. Colloquially, that would locate the deadline in time, which is acceptable.

So, the answer to your question is:

"I saw the deadline was a month past."

A few obvious ways to avoid the problem:

  • I saw that the deadline had passed. (not was)

  • I saw that the deadline had passed a month ago.

  • I saw that I was one month past the deadline.

  • I saw that I was past the deadline by a month.

If I try to stay as close as possible to your structure:

  • I saw that the deadline had been one month exceeded.
  • I saw that the deadline had been exceeded by one month.