The rate of social insurance in Spain has been increased by the Spanish Authorities. It is now €344.90 for Director Autonomous ( this is not to be confused with Self-employed autonomous which is a lower rate and which you cannot be registered for in Spain).
Over the course of 12 months this equates to €4138.80. As you only work 11 months of the year the €4138.80 is divided by 11 months which is €375 a month.
The social insurance will now be charged at €375 which covers your month off. This takes effect immediately and will be charged on January hours.