Employees may be asked to work within a system of ‘standby duty’ in which their physical presence at the workplace or another location appointed by the employer is not required (e.g. waiting time at home with the possibility of being called up). On 18 May 2015, the Belgian Supreme Court ruled that when an employee is called up, only the hours, during which actual performances are rendered, will be regarded as working time. On previous occasions, the Supreme Court had ruled that (1) waiting time as such is not working time and that (2) inactive hours during the waiting time do not need to be compensated with the same remuneration as actually performed working hours.