Employees may work on a full-time or part-time basis, whichever is agreed with the employer. There are no particular restrictions in this respect and the choice of the working time scheme is left to the parties to the employment contract.
However, you should bear in mind that full-time or part-time employment affects mutual rights and obligation of the employee and the employer.
First, it is forbidden to discriminate part-time employees or favour full-time employees with respect to entering into or terminating the employment contract, employment terms, promotion or access to professional training.
Second, employers are required to inform their employees about opportunities of full-time or part-time employment.
Third, part-time employment affects the rules of overtime work and paid vacation leave. Eg. the amount of vacation leave of a part-time employee should be calculated in proportion to that employee’s working time, with fractions being rounded up to a full day of leave. Further, basically a part-time employee working longer than stated in their employment contract will not be considered as working overtime provided that the 8-hour-per-day limit has not been exceeded. In this case the employment contract should indicate the number of hours above the contractual working time, exceeding of which earns the part-time employee the right to overtime premium.