Time sensitive posts

Hi,

Question. Is there any plugin that would show posts depending on when customer was register?

This is what i want to do:
I want to release new post to visitor every month, but this will depend on when he joined my blog.
For example,
Mark came today and joined. He sees post named “Month 1”, then after 30 days he sees post “Month 2” and “Month 2″…and then Jim join us, and he only sees “Month 1″…after 30 days he gets access to month 2 and Mark gets access to Month 3…So, at the same time people have access to different posts depending on time of join..

Cheers people!