@Nacho109
Please note the community for Spanish language is: Community Español
If you want the Christmas time period (CM) to "isolate" for bookings:
You need to create a ruleset with the minimum stay set to 5 nights and also you can set on which days check-in / check-out is allowed . Apply the ruleset to the CM
For the dates before this the CM you need to create a ruleset with the days guests can not check-out (to prevent guest book into the CM with shorter stays).
If your max stay is by default longer then 1 week, you have to limit max. stays also in the period before CM.