Thank you for using the Editorial Calendar. This looks like an error in the FAQ. I've just checked in a new version and it will be updated in the next release.
The new version looks like this:
= What users can use the calendar? =
The editorial calendar works differently based on your permissions.
* Administrators and Editors can use every feature available in the calendar.
* Authors can use the calendar to edit, move, and publish their own posts, but other people's posts are read-only.
* Contributors see everyone's posts and move their own posts, but can only save drafts.
* Subscribers can't see the calendar.
You can see how it looks for different usres on our Zack's WordPress Sandbox with the following users:
* edgar the Editor
* alice the Author
* conrad the Contributor
* sam the Subscriber
Each of theses users has the password test.
All of these users are live right now and you can try them out to see how it will work on your blog.
The basic idea is that all users have the same abilities in the calendar that they would without it. Contributors can normally see everyone's posts so we let them see those posts in the calendar too.
What do you think?