Is there a module for showing only posts in some defined date?
This is done with the Views module. Create a new view of content with a display type of 'block', and set it up as an unformatted list of teasers with links, then click 'Continue and edit'.

Add a filter on Content:Posted Day, and choose your conditions like 'is greater than' 'offset' '-10 days'.

You can then set any other views parameters to get what you want.

Save your view and go to admin/structure/block to find your block and place it where you want it.