@Jean-Marc172
to set it for the entire calendar
go to your listing's calendar
on the top right corner, you will see the "availability settings" link so click on it
go to the pricing and availability tab and scroll down to "restricted check-in / out days"
to set it to a certain period :
go to your listing's calendar
pick up the dates and on the right side of the window scroll down to "rule sets" / ad new rule set / customize check-in and check-out dates