SEO Content Machine allows you to manage and post multiple blog posts over a set schedule.
You can post multiple posts at one time directly in the post manager window.
You can also use the slightly more advanced post uploader content task.
Post Manager Window
It is the window located in the Blogs Manager ribbon tab.
The post view grid shows all your currently managed blog posts.
You can select multiple items (holding shift and clicking).
Right click on the grid -> Schedule Post
Schedule Post Settings
You can set a schedule that posts should appear live on the site.
Posts will only be visible to the public according to your set schedule.