Minimum stay

I have set a Minimum stay for friday and saturday of 2 nights. When I go through the front end as a non signed in guest, I am able to book either of those nights for only 1 night. 

To do it I went calendar > bulk edit> changed the date changed the days it applies to went to restrictions and selected 2 nights minimum stay and then apply.

How do I do this so guests can only book 2 nights on Friday and Saturday?