In an action before the National High Court in Spain, a Spanish trade union sought a judgment declaring Deutsche Bank SAE to be under an obligation to set up a system for recording the time worked each day by its members of staff. According to the union, the obligation to set up such a recording system was derived not only from national law but also from the Charter of Fundamental Rights of the European Union ("the Charter") and the Working Time Directive. The National High Court noted that the interpretation of Spanish law given by the Supreme Court in Spain deprived workers of essential evidence for demonstrating that they had worked in excess of maximum working time limits, such that Spanish law could not ensure the effective compliance with the obligations laid down by the Working Time Directive or the Directive on the health and safety of workers at work. Accordingly, the matter was referred to the CJEU for a preliminary ruling.

The CJEU ruled that, in order to ensure the effectiveness of the rights provided for in the Working Time Directive and the Charter, Member States must require employers to set up an objective, reliable and accessible system enabling the duration of time worked each day by each worker to be measured. It stated that the determination of the number of hours worked each day and each week was essential in order to establish whether the maximum weekly working time (including overtime) and minimum daily and weekly rest periods had been complied with.