If you must work on September 15th, remember that Article 148 of the Labour Code establishes that since it is a holiday, you must receive a double payment.
According to the Ministry of Labour, employees have the right to tell their employers they will not work on that day, regardless of the activity that they perform.
It doesn’t matter if it is a national or trasnational company, it must grant this holiday for the employees who are working in the country, and any agreement for the enjoyment of the holiday is null.
In addition, if you work overtime that day, the payment will triple.