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

template<typename date_type> 
struct acst_dst_trait {
  // types
  typedef date_type::day_of_week_type                day_of_week_type;  
  typedef date_type::month_type                      month_type;        
  typedef date_type::year_type                       year_type;         
  typedef date_time::last_kday_of_month< date_type > start_rule_functor;
  typedef date_time::last_kday_of_month< date_type > end_rule_functor;  

  // public static functions
  static day_of_week_type start_day(year_type);
  static month_type start_month(year_type);
  static day_of_week_type end_day(year_type);
  static month_type end_month(year_type);
  static int dst_start_offset_minutes();
  static int dst_end_offset_minutes();
  static int dst_shift_length_minutes();
  static date_type local_dst_start_day(year_type);
  static date_type local_dst_end_day(year_type);
};