Yesterday one of my workshop participants managed to expose my ignorance of the grammar of time. (I am of course fully versed in the texture of time.) This gives me a good opportunity to review the basics (CMOS 5.115-5.121).
There are three major tenses (past, present, and future), each of which also has a "perfect" tense "that indicates a comparatively more remote time" (5.115). Yesterday, I failed to distinguish the past tense from the present perfect. If you think about it, you have to grant that it isn't (formally speaking) easy. What is "a comparatively remote present" but the past?
Well, there is actually a good answer to that question. The "comparatively" refers to the major tense and "remote" really just means "before". Future perfect "refers to an act, state or condition that is expected to be completed before some other future act or time" (5.121).
The paper will be submitted at the end of the month. (future)
It will have been rewritten three times. (future perfect)
Past perfect "refers to an act, state or condition that was completed before another specified past time or past action" (5.120).
The paper was submitted at the end of the month. (past)
It had been rewritten three times. (past perfect)
Present perfect works the same way "It denotes an act, state, or condition that is now completed or continues up to this day" (5.119). It is a present tense because the "state of completion" remains in effect (once something is done it stays done—until things come undone).
The paper is being submitted as we speak. (present)
It has been rewritten three times. (present perfect)
Can we say "The paper is being submitted at the end of the month"? Formally, this is just the present tense. The odd thing is that indicates a time in the future. It would obviously mean something like "The paper is being written and will be submitted at the end of the month". So while I think it grammatical incorrect, it may actually be acceptable to say that a paper is being submitted at the end of the month. It means that we are working on it more or less continuously up til then. (I'm willing to hear objections.)
When we say that the paper is being written we are using the "present continuous" tense. The present indicative would run something like, "Smith writes interesting papers" or "The paper presents a complicated issue in simple terms."
Well, that helped me get things straight (past) and will help me to avoid embarrassment in the years to come (future). I hope it has helped you as well (present perfect) and that, when you look back on this post years from now, you will have found it to be helpful (future perfect) in your writing. It helps to write things like this down (present indicative), actually. It is helping right now (present continuous), isn't it? It had not helped simply to ignore one's ignorance of grammar (past perfect).