When I send an article back to the writer with a rewrite request, he has four days to resubmit. If he doesn't, the article expires but I still get paid for my work on it.
This is from the writer's bio in an expired article: "[Mr. Expired] is a freelance writer and began writing at the age of 18."
Kind of a late start, wouldn't you say. Apparently he hasn't learned how to rewrite yet.