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#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
* $Date$
*/
#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) {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
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