First of all, here's a video explaining the subject:
To make a Quick Change to the Minimum and Maximum stays in the Schedule:
Click on Schedule in the Main Menu,
Click on the offer of your choice on the My Schedule page ,
Click on the Min/Max stay quick modification link
Select the Offer you wish to modify
Select the tariff you wish to modify
Use the mouse to select the period concerned:
Day by day, by clicking on the given days
Week by week, by clicking on the week number
Month by month, by clicking on the cross to the left of each month
You can also combine specific days with several weeks and one or more months
Enter the minimum and maximum stay to be applied
Then click Apply
Note: In the same way as you can make a quick change to the minimum and maximum stay, you can also make a quick change to the prices.