With sentence C-55/18 of 14 May 2019, the European Court of Justice was called upon to rule on the appeal filed by a Spanish trade union, which asked it to ascertain whether European community labour law could lead to the obligation for employers to set up a system for logging working hours that allows for the verification of the hours set by the employment contract; for Spanish legislation, this would also include the sending of monthly overtime hours to trade union representatives. In rendering its sentence, the Court of Justice affirmed that the limitation of the maximum duration of working hours is effectively a fundamental right of the worker as also established by European Union legislation, which includes the right to daily and weekly rest periods. Consequently, Member States are required to issue internal regulations that oblige employers to track all employee work hours, so that it is always possible to verify the number of hours of work carried out, their distribution over time and the number of hours worked overtime.