#ifndef DATE_TIME_LOCAL_TIMEZONE_DEFS_HPP__

#define DATE_TIME_LOCAL_TIMEZONE_DEFS_HPP__



/* Copyright (c) 2002,2003 CrystalClear Software, Inc.

 * Use, modification and distribution is subject to the 

 * Boost Software License, Version 1.0. (See accompanying

 * file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)

 * Author: Jeff Garland 

 * $Date: 2008-02-27 15:00:24 -0500 (Wed, 27 Feb 2008) $

 */



#include "boost/date_time/dst_rules.hpp"



namespace boost {

  namespace date_time {



    // Configurations for common dst rules cases:

    // See http://www.wharton.co.uk/Support/sup_dst.htm for more

    // information on how various locales use dst rules



    //! Specification for daylight savings start rules in US

    /*! This class is used to configure dst_calc_engine template typically

        as follows:

        @code

          using namespace boost::gregorian;

          using namespace boost::posix_time;

          typedef us_dst_trait<date> us_dst_traits;

          typedef boost::date_time::dst_calc_engine<date, time_duration, 

                                                    us_dst_traits>  

                                                    us_dst_calc;

          //calculate the 2002 transition day of USA April 7 2002

          date dst_start = us_dst_calc::local_dst_start_day(2002); 



          //calculate the 2002 transition day of USA Oct 27 2002

          date dst_end = us_dst_calc::local_dst_end_day(2002); 

                                                    

          //check if a local time is in dst or not -- posible answers

          //are yes, no, invalid time label, ambiguous

          ptime t(...some time...);  

          if (us_dst::local_is_dst(t.date(), t.time_of_day()) 

              == boost::date_time::is_not_in_dst) 

          {



          }



        @endcode

        This generates a type suitable for the calculation of dst 

        transitions for the United States.  Of course other templates

        can be used for other locales.



    */



     template<class date_type>

     struct us_dst_trait

     {

       typedef typename date_type::day_of_week_type day_of_week_type;

       typedef typename date_type::month_type month_type;

       typedef typename date_type::year_type year_type;

       typedef date_time::nth_kday_of_month<date_type> start_rule_functor;

       typedef date_time::first_kday_of_month<date_type> end_rule_functor;

       typedef date_time::first_kday_of_month<date_type> start_rule_functor_pre2007;

       typedef date_time::last_kday_of_month<date_type> end_rule_functor_pre2007;

       static day_of_week_type start_day(year_type) {return Sunday;}

       static month_type start_month(year_type y) 

       {

         if (y < 2007) return Apr;

         return Mar;

       }

       static day_of_week_type end_day(year_type y) {return Sunday;}

       static month_type end_month(year_type y) 

       {

         if (y < 2007) return Oct;

         return Nov;

       }

       static date_type local_dst_start_day(year_type year)

       {

         if (year < 2007) {

           start_rule_functor_pre2007 start1(start_day(year), 

                                             start_month(year));

           return start1.get_date(year);

         }

         start_rule_functor start(start_rule_functor::second,

                                  start_day(year), 

                                  start_month(year));

         return start.get_date(year);

          

       }

       static date_type local_dst_end_day(year_type year)

       {

         if (year < 2007) {

           end_rule_functor_pre2007 end_rule(end_day(year), 

                                             end_month(year));

           return end_rule.get_date(year);

         }

         end_rule_functor end(end_day(year), 

                              end_month(year));

         return end.get_date(year);      

       }

       static int dst_start_offset_minutes() { return 120;}

       static int dst_end_offset_minutes() { return 120; }

       static int dst_shift_length_minutes() { return 60; }

     };



    //!Rules for daylight savings start in the EU (Last Sun in Mar)

    /*!These amount to the following:

      - Start of dst day is last Sunday in March

      - End day of dst is last Sunday in Oct

      - Going forward switch time is 2:00 am (offset 120 minutes)

      - Going back switch time is 3:00 am (off set 180 minutes)

      - Shift duration is one hour (60 minutes)

    */

    template<class date_type>

    struct eu_dst_trait

    {

      typedef typename date_type::day_of_week_type day_of_week_type;

      typedef typename date_type::month_type month_type;

      typedef typename 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;

      static day_of_week_type start_day(year_type) {return Sunday;}

      static month_type start_month(year_type) {return Mar;}

      static day_of_week_type end_day(year_type) {return Sunday;}

      static month_type end_month(year_type) {return Oct;}

      static int dst_start_offset_minutes() { return 120;}

      static int dst_end_offset_minutes() { return 180; }

      static int dst_shift_length_minutes() { return 60; }

      static date_type local_dst_start_day(year_type year)

      {

        start_rule_functor start(start_day(year), 

                                 start_month(year));

        return start.get_date(year);      

      }

      static date_type local_dst_end_day(year_type year)

      {

        end_rule_functor end(end_day(year), 

                             end_month(year));

        return end.get_date(year);      

      }

    };



    //! Alternative dst traits for some parts of the United Kingdom

    /* Several places in the UK use EU start and end rules for the 

       day, but different local conversion times (eg: forward change at 1:00 

       am local and  backward change at 2:00 am dst instead of 2:00am 

       forward and 3:00am back for the EU).

    */

    template<class date_type>

    struct uk_dst_trait : public eu_dst_trait<date_type>

    {

      static int dst_start_offset_minutes() { return 60;}

      static int dst_end_offset_minutes() { return 120; }

      static int dst_shift_length_minutes() { return 60; }

    };



    //Rules for Adelaide Australia

    template<class date_type>

    struct acst_dst_trait

    {

      typedef typename date_type::day_of_week_type day_of_week_type;

      typedef typename date_type::month_type month_type;

      typedef typename 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;

      static day_of_week_type start_day(year_type) {return Sunday;}

      static month_type start_month(year_type) {return Oct;}

      static day_of_week_type end_day(year_type) {return Sunday;}

      static month_type end_month(year_type) {return Mar;}

      static int dst_start_offset_minutes() { return 120;}

      static int dst_end_offset_minutes() { return 180; }

      static int dst_shift_length_minutes() { return 60; }

      static date_type local_dst_start_day(year_type year)

      {

        start_rule_functor start(start_day(year), 

                                 start_month(year));

        return start.get_date(year);      

      }

      static date_type local_dst_end_day(year_type year)

      {

        end_rule_functor end(end_day(year), 

                             end_month(year));

        return end.get_date(year);      

      }

    };

    

    









} } //namespace boost::date_time





#endif

