Default Date/Duration when scheduling posts

Hi!
I am creating posts that are scheduled with a future date for publishing, not the create date (I create a post today that will have a published date of, say, next year). They are supposed to expire 1 day after their published date.

I set up the Default Date/Duration to +1 day. When I create the new post, the date in the post-expirator metabox is one day later, which is I guess how it is intended to work.

However, since I change the publish date to a future date, I would like the post expiration to change to +1 day after that day.

Is that possible?

Thanks!

http://wordpress.org/extend/plugins/post-expirator/