Employees who so wish may, in agreement with their employer, give up part of their rest days in return for an increase in their salary. The agreement between the employee and the employer must be in writing.
A rider to the lump-sum agreement concluded between the employee and the employer determines the rate of the increase applicable to the remuneration for this additional working time, which may not be less than 10%. This amendment is valid for the current year. It cannot be tacitly renewed.