Must Article 17(3)(c)(iii) of Directive 2003/88/EC concerning certain aspects of the organisation of working time be interpreted as enabling Member States to exclude certain categories of firefighters recruited by the public fire services from all the provisions transposing that Directive, including the provision that defines working time and rest periods?Inasmuch as Directive 2003/88 of 4 November 2003 concerning certain aspects of the organisation of working time provides for only minimum requirements, must it be interpreted as not preventing the national legislature from retaining or adopting a less restrictive definition of working time?Taking account of Article 153(5) TFEU and of the objectives of Directive 2003/88 concerning certain aspects of the organisation of working time, must Article 2 of that Directive, in so far as it defines the principal concepts used in the Directive, in particular those of working time and rest periods, be interpreted to the effect that it is not applicable to the concept of working time which serves to determine the remuneration owed in the case of home-based on-call time?Does Directive 2003/88 of 4 November 2003 concerning certain aspects of the organisation of working time prevent home-based on-call time from being regarded as working time when, although the on-call time is undertaken at the home of the worker, the constraints on him during the on-call time (such as the duty to respond to calls from his employer within eight minutes) very significantly restrict the opportunities to undertake other activities?