Working hours of workers are regulated in a direct or indirect way by numerous sources of law, both domestic, starting from the Constitution of the Republic of 4Croatia and the Labour Act5, as well as international conventions, international treaties and the acquis communautaire of the European Union, which as a full member must be respected by our country. Thus, the Labour Act also implemented Directive 2003/88/EC of the European Parliament and of the Council of 4 November 2003 into the legal system of the Republic of Croatia, which set minimum safety and health requirements for the organization of working hours of workers. The Labour Act as a basic regulation of Croatian labour legislation defines working hours as "the time in which a worker is obliged to perform tasks, i.e. in which he is ready (available) to perform tasks according to the instructions of the employer, at the place where his work is performed or in another place determined by the employer “.6 The employment relationship is based on the employment legislation by concluding employment contracts, whereby it is necessary to know the legal norms of the Labour Act relating to working hours. It is also important to know the difference between full, part-time and part-time work, and above all to know the rights arising from overtime or supplementary work. It is necessary to know how to distinguish between legal institutes of working time schedules and redistribution of working hours. In this research, in accordance with his title topic, the author deals with the labor and legal matter.