// In header: <boost/date_time/date_formatting.hpp>

template<typename date_type, typename format_type, typename charT = char> 
class date_formatter {
public:
  // types
  typedef std::basic_string< charT > string_type;

  // public static functions
  static string_type date_to_string(date_type);
  static std::string date_to_string(date_type);
};