Automatic scheduling of content per user basis

After a forum search and struggle to find a solution, i am posting my question here…

First a short description of what i need (explanation is below)
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I need a get_post option that shows next post to each logged user 12 hours after the previous has been read by this same logged user… It doesn’t matter, it can be a page or a post… Showing of posts should be totally user specific …
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EXPLANATION:

I would like to put a course on my site that does the following:

I would add 30 posts that are visible to logged in users on the following way.

When an user visits the “course page”, he will only see the first post. After reading it, the second post will be visible after certain amount of time, say 24 hours. And after reading the second post, the third will be available after 12 hours…

That means that the new posts will be available on different times for a different users (that’s why per user basics).

The easiest solution would be a module (haven’t found it), but if not, a simple code with get_posts()… I was checking this one, but haven’t been able to find the right rule…