Only rarely do decisions of the European Court of Justice (ECJ) attract so much media attention as the ruling of May 14 2019 on the recording of working time. The ECJ has ruled that the Working Time Directive (EU Directive 2003/88) and the EU Charter of Fundamental Rights require an “objective and reliable system” for recording working time. The reason for the decision was a bill on Spanish working time law, which – comparable to the German Working Time Act (§ 16 (2) ArbZG) – provides for an obligation to record overtime hours alone. This is not sufficient for the systematic recording of working times now required by the ECJ. Rather, the total number of working hours needs to be documented.