In Federacion de Servicios de Comisiones Obreras v Deutsche Bank SAE Advocate General Pitruzella considered  a referral from the Spanish National Court asking if it is necessary for Member States to make it compulsory for employers to introduce systems to measure the actual duration of the working day and working week.   

The question arose in the context of a group action brought by a federation of trade unions before the Spanish National Court.  They sought a declaration that Deutshe Bank were obliged to set up a system which records the actual number of hours worked daily and makes it possible to check that working times laid down in legislation and collective agreements are properly adhered to.  Rather than recording actual hours worked, Deutsche Bank used an "absences calendar" which permitted the recording of absences for full working days (by reason of holiday or sickness absence or similar).   

The background to the case was that the Employment and Social Security Inspectorates had called upon Deutsche Bank to set up a system to record daily working time, and when they had failed to do so an infringement notice containing a penalty was drawn up.   However , the penalty had not been imposed because the Spanish Supreme Court had concluded that  there was no obligation under Spanish law to record ordinary working time, it was only necessary to keep a record of overtime worked for the purposes of communicating that to union representatives at the end of each month.  

When the unions sought a declaration from the Spanish National Court it expressed some doubt as to whether the Spanish Supreme Court's position was consistent with EU law and made the referral to the ECJ.   

The Advocate General's opinion was that national legislation that does not impose any legal obligation on employers to introduce a system to record daily working time is inconsistent with EU law.  EU law must be interpreted as imposing an obligation on employers  to set up a system for recording actual daily working time for full-timers who have not expressly agreed, individually or collectively, to work overtime.  

In the UK, the Working Time Regulations require employers to keep "adequate records" showing the limits on average working time, night work and the provision of health and safety assessments are being complied with in the case of each worker.  Employers are not however obliged to keep records in relation to daily or weekly rest nor is there a requirement to specifically record all hours of work.   

While the opinion of the Advocate General is not legally binding, the ECJ regularly reach the same conclusion.  If that were to happen here then there will be a question mark over whether the law in the UK is compliant.  The impact of any subsequent decision by the ECJ will depend on what happens with Brexit.