// In header: <boost/date_time/date_formatting_locales.hpp>
template<typename weekday_type, typename facet_type, typename charT = char> 
class ostream_weekday_formatter {
public:
  // types
  typedef facet_type::month_type      month_type;  
  typedef std::basic_ostream< charT > ostream_type;
  // public static functions
  static void format_weekday(const weekday_type &, ostream_type &, 
                             const facet_type &, bool);
};