I actually have a use for this that's not splogging, so please read! I have a tutoring site on which I plan on putting a problem of the day. I would like to post the solution to the problem as a comment at a later time, without having to be a slave to my blog and be in front of my computer. Is there a way to do that, preferably freely?
Posting the answer inside a comment will go un-noticed and get buried. It would also be harder to find. A more elegant solution would be to set the answer inside a custom meta-field (or create a meta-box for it in the editor to handle it), then have the answer reveal itself inside the post after x-amount of days. No, there is not a plugin that I know of that will do this. But it is fairly easy to script into the post logic.
While we are on this subject. It dawned on me that if you could post-date a post, can you post-date comments too?
Do you know of any tutorial? That is the first thing I tried. It simply edits the text of the post date but does not delay the post.
I thought of a better method -- shortcodes. Create a shortcode for your answer with one attribute, the date you want to publish the answer. Look for shortcode tutorials. They are real easy to implement.