392 lines
16 KiB
Plaintext
392 lines
16 KiB
Plaintext
|
#ifndef DATE_TIME_DST_RULES_HPP__
|
||
|
|
#define DATE_TIME_DST_RULES_HPP__
|
||
|
|
|
||
|
|
/* Copyright (c) 2002,2003, 2007 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, Bart Garst
|
||
|
|
* $Date$
|
||
|
|
*/
|
||
|
|
|
||
|
|
/*! @file dst_rules.hpp
|
||
|
|
Contains template class to provide static dst rule calculations
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include "boost/date_time/date_generators.hpp"
|
||
|
|
#include "boost/date_time/period.hpp"
|
||
|
|
#include "boost/date_time/date_defs.hpp"
|
||
|
|
#include <stdexcept>
|
||
|
|
|
||
|
|
namespace boost {
|
||
|
|
namespace date_time {
|
||
|
|
|
||
|
|
enum time_is_dst_result {is_not_in_dst, is_in_dst,
|
||
|
|
ambiguous, invalid_time_label};
|
||
|
|
|
||
|
|
|
||
|
|
//! Dynamic class used to caluclate dst transition information
|
||
|
|
template<class date_type_,
|
||
|
|
class time_duration_type_>
|
||
|
|
class dst_calculator
|
||
|
|
{
|
||
|
|
public:
|
||
|
|
typedef time_duration_type_ time_duration_type;
|
||
|
|
typedef date_type_ date_type;
|
||
|
|
|
||
|
|
//! Check the local time offset when on dst start day
|
||
|
|
/*! On this dst transition, the time label between
|
||
|
|
* the transition boundary and the boudary + the offset
|
||
|
|
* are invalid times. If before the boundary then still
|
||
|
|
* not in dst.
|
||
|
|
*@param time_of_day Time offset in the day for the local time
|
||
|
|
*@param dst_start_offset_minutes Local day offset for start of dst
|
||
|
|
*@param dst_length_minutes Number of minutes to adjust clock forward
|
||
|
|
*@retval status of time label w.r.t. dst
|
||
|
|
*/
|
||
|
|
static time_is_dst_result
|
||
|
|
process_local_dst_start_day(const time_duration_type& time_of_day,
|
||
|
|
unsigned int dst_start_offset_minutes,
|
||
|
|
long dst_length_minutes)
|
||
|
|
{
|
||
|
|
//std::cout << "here" << std::endl;
|
||
|
|
if (time_of_day < time_duration_type(0,dst_start_offset_minutes,0)) {
|
||
|
|
return is_not_in_dst;
|
||
|
|
}
|
||
|
|
long offset = dst_start_offset_minutes + dst_length_minutes;
|
||
|
|
if (time_of_day >= time_duration_type(0,offset,0)) {
|
||
|
|
return is_in_dst;
|
||
|
|
}
|
||
|
|
return invalid_time_label;
|
||
|
|
}
|
||
|
|
|
||
|
|
//! Check the local time offset when on the last day of dst
|
||
|
|
/*! This is the calculation for the DST end day. On that day times
|
||
|
|
* prior to the conversion time - dst_length (1 am in US) are still
|
||
|
|
* in dst. Times between the above and the switch time are
|
||
|
|
* ambiguous. Times after the start_offset are not in dst.
|
||
|
|
*@param time_of_day Time offset in the day for the local time
|
||
|
|
*@param dst_end_offset_minutes Local time of day for end of dst
|
||
|
|
*@retval status of time label w.r.t. dst
|
||
|
|
*/
|
||
|
|
static time_is_dst_result
|
||
|
|
process_local_dst_end_day(const time_duration_type& time_of_day,
|
||
|
|
unsigned int dst_end_offset_minutes,
|
||
|
|
long dst_length_minutes)
|
||
|
|
{
|
||
|
|
//in US this will be 60 so offset in day is 1,0,0
|
||
|
|
int offset = dst_end_offset_minutes-dst_length_minutes;
|
||
|
|
if (time_of_day < time_duration_type(0,offset,0)) {
|
||
|
|
return is_in_dst;
|
||
|
|
}
|
||
|
|
if (time_of_day >= time_duration_type(0,dst_end_offset_minutes,0)) {
|
||
|
|
return is_not_in_dst;
|
||
|
|
}
|
||
|
|
return ambiguous;
|
||
|
|
}
|
||
|
|
|
||
|
|
//! Calculates if the given local time is dst or not
|
||
|
|
/*! Determines if the time is really in DST or not. Also checks for
|
||
|
|
* invalid and ambiguous.
|
||
|
|
* @param current_day The day to check for dst
|
||
|
|
* @param time_of_day Time offset within the day to check
|
||
|
|
* @param dst_start_day Starting day of dst for the given locality
|
||
|
|
* @param dst_start_offset Time offset within day for dst boundary
|
||
|
|
* @param dst_end_day Ending day of dst for the given locality
|
||
|
|
* @param dst_end_offset Time offset within day given in dst for dst boundary
|
||
|
|
* @param dst_length lenght of dst adjusment
|
||
|
|
* @retval The time is either ambiguous, invalid, in dst, or not in dst
|
||
|
|
*/
|
||
|
|
static time_is_dst_result
|
||
|
|
local_is_dst(const date_type& current_day,
|
||
|
|
const time_duration_type& time_of_day,
|
||
|
|
const date_type& dst_start_day,
|
||
|
|
const time_duration_type& dst_start_offset,
|
||
|
|
const date_type& dst_end_day,
|
||
|
|
const time_duration_type& dst_end_offset,
|
||
|
|
const time_duration_type& dst_length_minutes)
|
||
|
|
{
|
||
|
|
unsigned int start_minutes =
|
||
|
|
dst_start_offset.hours() * 60 + dst_start_offset.minutes();
|
||
|
|
unsigned int end_minutes =
|
||
|
|
dst_end_offset.hours() * 60 + dst_end_offset.minutes();
|
||
|
|
long length_minutes =
|
||
|
|
dst_length_minutes.hours() * 60 + dst_length_minutes.minutes();
|
||
|
|
|
||
|
|
return local_is_dst(current_day, time_of_day,
|
||
|
|
dst_start_day, start_minutes,
|
||
|
|
dst_end_day, end_minutes,
|
||
|
|
length_minutes);
|
||
|
|
}
|
||
|
|
|
||
|
|
//! Calculates if the given local time is dst or not
|
||
|
|
/*! Determines if the time is really in DST or not. Also checks for
|
||
|
|
* invalid and ambiguous.
|
||
|
|
* @param current_day The day to check for dst
|
||
|
|
* @param time_of_day Time offset within the day to check
|
||
|
|
* @param dst_start_day Starting day of dst for the given locality
|
||
|
|
* @param dst_start_offset_minutes Offset within day for dst
|
||
|
|
* boundary (eg 120 for US which is 02:00:00)
|
||
|
|
* @param dst_end_day Ending day of dst for the given locality
|
||
|
|
* @param dst_end_offset_minutes Offset within day given in dst for dst
|
||
|
|
* boundary (eg 120 for US which is 02:00:00)
|
||
|
|
* @param dst_length_minutes Length of dst adjusment (eg: 60 for US)
|
||
|
|
* @retval The time is either ambiguous, invalid, in dst, or not in dst
|
||
|
|
*/
|
||
|
|
static time_is_dst_result
|
||
|
|
local_is_dst(const date_type& current_day,
|
||
|
|
const time_duration_type& time_of_day,
|
||
|
|
const date_type& dst_start_day,
|
||
|
|
unsigned int dst_start_offset_minutes,
|
||
|
|
const date_type& dst_end_day,
|
||
|
|
unsigned int dst_end_offset_minutes,
|
||
|
|
long dst_length_minutes)
|
||
|
|
{
|
||
|
|
//in northern hemisphere dst is in the middle of the year
|
||
|
|
if (dst_start_day < dst_end_day) {
|
||
|
|
if ((current_day > dst_start_day) && (current_day < dst_end_day)) {
|
||
|
|
return is_in_dst;
|
||
|
|
}
|
||
|
|
if ((current_day < dst_start_day) || (current_day > dst_end_day)) {
|
||
|
|
return is_not_in_dst;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
else {//southern hemisphere dst is at begining /end of year
|
||
|
|
if ((current_day < dst_start_day) && (current_day > dst_end_day)) {
|
||
|
|
return is_not_in_dst;
|
||
|
|
}
|
||
|
|
if ((current_day > dst_start_day) || (current_day < dst_end_day)) {
|
||
|
|
return is_in_dst;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if (current_day == dst_start_day) {
|
||
|
|
return process_local_dst_start_day(time_of_day,
|
||
|
|
dst_start_offset_minutes,
|
||
|
|
dst_length_minutes);
|
||
|
|
}
|
||
|
|
|
||
|
|
if (current_day == dst_end_day) {
|
||
|
|
return process_local_dst_end_day(time_of_day,
|
||
|
|
dst_end_offset_minutes,
|
||
|
|
dst_length_minutes);
|
||
|
|
}
|
||
|
|
//you should never reach this statement
|
||
|
|
return invalid_time_label;
|
||
|
|
}
|
||
|
|
|
||
|
|
};
|
||
|
|
|
||
|
|
|
||
|
|
//! Compile-time configurable daylight savings time calculation engine
|
||
|
|
/* This template provides the ability to configure a daylight savings
|
||
|
|
* calculation at compile time covering all the cases. Unfortunately
|
||
|
|
* because of the number of dimensions related to daylight savings
|
||
|
|
* calculation the number of parameters is high. In addition, the
|
||
|
|
* start and end transition rules are complex types that specify
|
||
|
|
* an algorithm for calculation of the starting day and ending
|
||
|
|
* day of daylight savings time including the month and day
|
||
|
|
* specifications (eg: last sunday in October).
|
||
|
|
*
|
||
|
|
* @param date_type A type that represents dates, typically gregorian::date
|
||
|
|
* @param time_duration_type Used for the offset in the day calculations
|
||
|
|
* @param dst_traits A set of traits that define the rules of dst
|
||
|
|
* calculation. The dst_trait must include the following:
|
||
|
|
* start_rule_functor - Rule to calculate the starting date of a
|
||
|
|
* dst transition (eg: last_kday_of_month).
|
||
|
|
* start_day - static function that returns month of dst start for
|
||
|
|
* start_rule_functor
|
||
|
|
* start_month -static function that returns day or day of week for
|
||
|
|
* dst start of dst
|
||
|
|
* end_rule_functor - Rule to calculate the end of dst day.
|
||
|
|
* end_day - static fucntion that returns end day for end_rule_functor
|
||
|
|
* end_month - static function that returns end month for end_rule_functor
|
||
|
|
* dst_start_offset_minutes - number of minutes from start of day to transition to dst -- 120 (or 2:00 am) is typical for the U.S. and E.U.
|
||
|
|
* dst_start_offset_minutes - number of minutes from start of day to transition off of dst -- 180 (or 3:00 am) is typical for E.U.
|
||
|
|
* dst_length_minutes - number of minutes that dst shifts clock
|
||
|
|
*/
|
||
|
|
template<class date_type,
|
||
|
|
class time_duration_type,
|
||
|
|
class dst_traits>
|
||
|
|
class dst_calc_engine
|
||
|
|
{
|
||
|
|
public:
|
||
|
|
typedef typename date_type::year_type year_type;
|
||
|
|
typedef typename date_type::calendar_type calendar_type;
|
||
|
|
typedef dst_calculator<date_type, time_duration_type> dstcalc;
|
||
|
|
|
||
|
|
//! Calculates if the given local time is dst or not
|
||
|
|
/*! Determines if the time is really in DST or not. Also checks for
|
||
|
|
* invalid and ambiguous.
|
||
|
|
* @retval The time is either ambiguous, invalid, in dst, or not in dst
|
||
|
|
*/
|
||
|
|
static time_is_dst_result local_is_dst(const date_type& d,
|
||
|
|
const time_duration_type& td)
|
||
|
|
{
|
||
|
|
|
||
|
|
year_type y = d.year();
|
||
|
|
date_type dst_start = local_dst_start_day(y);
|
||
|
|
date_type dst_end = local_dst_end_day(y);
|
||
|
|
return dstcalc::local_is_dst(d,td,
|
||
|
|
dst_start,
|
||
|
|
dst_traits::dst_start_offset_minutes(),
|
||
|
|
dst_end,
|
||
|
|
dst_traits::dst_end_offset_minutes(),
|
||
|
|
dst_traits::dst_shift_length_minutes());
|
||
|
|
|
||
|
|
}
|
||
|
|
|
||
|
|
static bool is_dst_boundary_day(date_type d)
|
||
|
|
{
|
||
|
|
year_type y = d.year();
|
||
|
|
return ((d == local_dst_start_day(y)) ||
|
||
|
|
(d == local_dst_end_day(y)));
|
||
|
|
}
|
||
|
|
|
||
|
|
//! The time of day for the dst transition (eg: typically 01:00:00 or 02:00:00)
|
||
|
|
static time_duration_type dst_offset()
|
||
|
|
{
|
||
|
|
return time_duration_type(0,dst_traits::dst_shift_length_minutes(),0);
|
||
|
|
}
|
||
|
|
|
||
|
|
static date_type local_dst_start_day(year_type year)
|
||
|
|
{
|
||
|
|
return dst_traits::local_dst_start_day(year);
|
||
|
|
}
|
||
|
|
|
||
|
|
static date_type local_dst_end_day(year_type year)
|
||
|
|
{
|
||
|
|
return dst_traits::local_dst_end_day(year);
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
};
|
||
|
|
|
||
|
|
//! Depricated: Class to calculate dst boundaries for US time zones
|
||
|
|
/* Use dst_calc_engine instead.
|
||
|
|
* In 2007 US/Canada DST rules changed
|
||
|
|
* (http://en.wikipedia.org/wiki/Energy_Policy_Act_of_2005#Change_to_daylight_saving_time).
|
||
|
|
*/
|
||
|
|
template<class date_type_,
|
||
|
|
class time_duration_type_,
|
||
|
|
unsigned int dst_start_offset_minutes=120, //from start of day
|
||
|
|
short dst_length_minutes=60> //1 hour == 60 min in US
|
||
|
|
class us_dst_rules
|
||
|
|
{
|
||
|
|
public:
|
||
|
|
typedef time_duration_type_ time_duration_type;
|
||
|
|
typedef date_type_ date_type;
|
||
|
|
typedef typename date_type::year_type year_type;
|
||
|
|
typedef typename date_type::calendar_type calendar_type;
|
||
|
|
typedef date_time::last_kday_of_month<date_type> lkday;
|
||
|
|
typedef date_time::first_kday_of_month<date_type> fkday;
|
||
|
|
typedef date_time::nth_kday_of_month<date_type> nkday;
|
||
|
|
typedef dst_calculator<date_type, time_duration_type> dstcalc;
|
||
|
|
|
||
|
|
//! Calculates if the given local time is dst or not
|
||
|
|
/*! Determines if the time is really in DST or not. Also checks for
|
||
|
|
* invalid and ambiguous.
|
||
|
|
* @retval The time is either ambiguous, invalid, in dst, or not in dst
|
||
|
|
*/
|
||
|
|
static time_is_dst_result local_is_dst(const date_type& d,
|
||
|
|
const time_duration_type& td)
|
||
|
|
{
|
||
|
|
|
||
|
|
year_type y = d.year();
|
||
|
|
date_type dst_start = local_dst_start_day(y);
|
||
|
|
date_type dst_end = local_dst_end_day(y);
|
||
|
|
return dstcalc::local_is_dst(d,td,
|
||
|
|
dst_start,dst_start_offset_minutes,
|
||
|
|
dst_end, dst_start_offset_minutes,
|
||
|
|
dst_length_minutes);
|
||
|
|
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
static bool is_dst_boundary_day(date_type d)
|
||
|
|
{
|
||
|
|
year_type y = d.year();
|
||
|
|
return ((d == local_dst_start_day(y)) ||
|
||
|
|
(d == local_dst_end_day(y)));
|
||
|
|
}
|
||
|
|
|
||
|
|
static date_type local_dst_start_day(year_type year)
|
||
|
|
{
|
||
|
|
if (year >= year_type(2007)) {
|
||
|
|
//second sunday in march
|
||
|
|
nkday ssim(nkday::second, Sunday, gregorian::Mar);
|
||
|
|
return ssim.get_date(year);
|
||
|
|
} else {
|
||
|
|
//first sunday in april
|
||
|
|
fkday fsia(Sunday, gregorian::Apr);
|
||
|
|
return fsia.get_date(year);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
static date_type local_dst_end_day(year_type year)
|
||
|
|
{
|
||
|
|
if (year >= year_type(2007)) {
|
||
|
|
//first sunday in november
|
||
|
|
fkday fsin(Sunday, gregorian::Nov);
|
||
|
|
return fsin.get_date(year);
|
||
|
|
} else {
|
||
|
|
//last sunday in october
|
||
|
|
lkday lsio(Sunday, gregorian::Oct);
|
||
|
|
return lsio.get_date(year);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
static time_duration_type dst_offset()
|
||
|
|
{
|
||
|
|
return time_duration_type(0,dst_length_minutes,0);
|
||
|
|
}
|
||
|
|
|
||
|
|
private:
|
||
|
|
|
||
|
|
|
||
|
|
};
|
||
|
|
|
||
|
|
//! Used for local time adjustments in places that don't use dst
|
||
|
|
template<class date_type_, class time_duration_type_>
|
||
|
|
class null_dst_rules
|
||
|
|
{
|
||
|
|
public:
|
||
|
|
typedef time_duration_type_ time_duration_type;
|
||
|
|
typedef date_type_ date_type;
|
||
|
|
|
||
|
|
|
||
|
|
//! Calculates if the given local time is dst or not
|
||
|
|
/*! @retval Always is_not_in_dst since this is for zones without dst
|
||
|
|
*/
|
||
|
|
static time_is_dst_result local_is_dst(const date_type&,
|
||
|
|
const time_duration_type&)
|
||
|
|
{
|
||
|
|
return is_not_in_dst;
|
||
|
|
}
|
||
|
|
|
||
|
|
//! Calculates if the given utc time is in dst
|
||
|
|
static time_is_dst_result utc_is_dst(const date_type&,
|
||
|
|
const time_duration_type&)
|
||
|
|
{
|
||
|
|
return is_not_in_dst;
|
||
|
|
}
|
||
|
|
|
||
|
|
static bool is_dst_boundary_day(date_type /*d*/)
|
||
|
|
{
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
|
||
|
|
static time_duration_type dst_offset()
|
||
|
|
{
|
||
|
|
return time_duration_type(0,0,0);
|
||
|
|
}
|
||
|
|
|
||
|
|
};
|
||
|
|
|
||
|
|
|
||
|
|
} } //namespace date_time
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
#endif
|