1#ifndef DATE_TIME_LOCAL_TIMEZONE_DEFS_HPP__
2#define DATE_TIME_LOCAL_TIMEZONE_DEFS_HPP__
3
4/* Copyright (c) 2002,2003 CrystalClear Software, Inc.
5 * Use, modification and distribution is subject to the
6 * Boost Software License, Version 1.0. (See accompanying
7 * file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
8 * Author: Jeff Garland
9 * $Date$
10 */
11
12#include "boost/date_time/dst_rules.hpp"
13
14namespace boost {
15 namespace date_time {
16
17 // Configurations for common dst rules cases:
18 // See http://www.wharton.co.uk/Support/sup_dst.htm for more
19 // information on how various locales use dst rules
20
21 //! Specification for daylight savings start rules in US
22 /*! This class is used to configure dst_calc_engine template typically
23 as follows:
24 @code
25 using namespace boost::gregorian;
26 using namespace boost::posix_time;
27 typedef us_dst_trait<date> us_dst_traits;
28 typedef boost::date_time::dst_calc_engine<date, time_duration,
29 us_dst_traits>
30 us_dst_calc;
31 //calculate the 2002 transition day of USA April 7 2002
32 date dst_start = us_dst_calc::local_dst_start_day(2002);
33
34 //calculate the 2002 transition day of USA Oct 27 2002
35 date dst_end = us_dst_calc::local_dst_end_day(2002);
36
37 //check if a local time is in dst or not -- posible answers
38 //are yes, no, invalid time label, ambiguous
39 ptime t(...some time...);
40 if (us_dst::local_is_dst(t.date(), t.time_of_day())
41 == boost::date_time::is_not_in_dst)
42 {
43
44 }
45
46 @endcode
47 This generates a type suitable for the calculation of dst
48 transitions for the United States. Of course other templates
49 can be used for other locales.
50
51 */
52
53 template<class date_type>
54 struct us_dst_trait
55 {
56 typedef typename date_type::day_of_week_type day_of_week_type;
57 typedef typename date_type::month_type month_type;
58 typedef typename date_type::year_type year_type;
59 typedef date_time::nth_kday_of_month<date_type> start_rule_functor;
60 typedef date_time::first_kday_of_month<date_type> end_rule_functor;
61 typedef date_time::first_kday_of_month<date_type> start_rule_functor_pre2007;
62 typedef date_time::last_kday_of_month<date_type> end_rule_functor_pre2007;
63 static day_of_week_type start_day(year_type) {return Sunday;}
64 static month_type start_month(year_type y)
65 {
66 if (y < 2007) return Apr;
67 return Mar;
68 }
69 static day_of_week_type end_day(year_type) {return Sunday;}
70 static month_type end_month(year_type y)
71 {
72 if (y < 2007) return Oct;
73 return Nov;
74 }
75 static date_type local_dst_start_day(year_type year)
76 {
77 if (year < 2007) {
78 start_rule_functor_pre2007 start1(start_day(year),
79 start_month(y: year));
80 return start1.get_date(year);
81 }
82 start_rule_functor start(start_rule_functor::second,
83 start_day(year),
84 start_month(y: year));
85 return start.get_date(year);
86
87 }
88 static date_type local_dst_end_day(year_type year)
89 {
90 if (year < 2007) {
91 end_rule_functor_pre2007 end_rule(end_day(year),
92 end_month(y: year));
93 return end_rule.get_date(year);
94 }
95 end_rule_functor end(end_day(year),
96 end_month(y: year));
97 return end.get_date(year);
98 }
99 static int dst_start_offset_minutes() { return 120;}
100 static int dst_end_offset_minutes() { return 120; }
101 static int dst_shift_length_minutes() { return 60; }
102 };
103
104 //!Rules for daylight savings start in the EU (Last Sun in Mar)
105 /*!These amount to the following:
106 - Start of dst day is last Sunday in March
107 - End day of dst is last Sunday in Oct
108 - Going forward switch time is 2:00 am (offset 120 minutes)
109 - Going back switch time is 3:00 am (off set 180 minutes)
110 - Shift duration is one hour (60 minutes)
111 */
112 template<class date_type>
113 struct eu_dst_trait
114 {
115 typedef typename date_type::day_of_week_type day_of_week_type;
116 typedef typename date_type::month_type month_type;
117 typedef typename date_type::year_type year_type;
118 typedef date_time::last_kday_of_month<date_type> start_rule_functor;
119 typedef date_time::last_kday_of_month<date_type> end_rule_functor;
120 static day_of_week_type start_day(year_type) {return Sunday;}
121 static month_type start_month(year_type) {return Mar;}
122 static day_of_week_type end_day(year_type) {return Sunday;}
123 static month_type end_month(year_type) {return Oct;}
124 static int dst_start_offset_minutes() { return 120;}
125 static int dst_end_offset_minutes() { return 180; }
126 static int dst_shift_length_minutes() { return 60; }
127 static date_type local_dst_start_day(year_type year)
128 {
129 start_rule_functor start(start_day(year),
130 start_month(year));
131 return start.get_date(year);
132 }
133 static date_type local_dst_end_day(year_type year)
134 {
135 end_rule_functor end(end_day(year),
136 end_month(year));
137 return end.get_date(year);
138 }
139 };
140
141 //! Alternative dst traits for some parts of the United Kingdom
142 /* Several places in the UK use EU start and end rules for the
143 day, but different local conversion times (eg: forward change at 1:00
144 am local and backward change at 2:00 am dst instead of 2:00am
145 forward and 3:00am back for the EU).
146 */
147 template<class date_type>
148 struct uk_dst_trait : public eu_dst_trait<date_type>
149 {
150 static int dst_start_offset_minutes() { return 60;}
151 static int dst_end_offset_minutes() { return 120; }
152 static int dst_shift_length_minutes() { return 60; }
153 };
154
155 //Rules for Adelaide Australia
156 template<class date_type>
157 struct acst_dst_trait
158 {
159 typedef typename date_type::day_of_week_type day_of_week_type;
160 typedef typename date_type::month_type month_type;
161 typedef typename date_type::year_type year_type;
162 typedef date_time::last_kday_of_month<date_type> start_rule_functor;
163 typedef date_time::last_kday_of_month<date_type> end_rule_functor;
164 static day_of_week_type start_day(year_type) {return Sunday;}
165 static month_type start_month(year_type) {return Oct;}
166 static day_of_week_type end_day(year_type) {return Sunday;}
167 static month_type end_month(year_type) {return Mar;}
168 static int dst_start_offset_minutes() { return 120;}
169 static int dst_end_offset_minutes() { return 180; }
170 static int dst_shift_length_minutes() { return 60; }
171 static date_type local_dst_start_day(year_type year)
172 {
173 start_rule_functor start(start_day(year),
174 start_month(year));
175 return start.get_date(year);
176 }
177 static date_type local_dst_end_day(year_type year)
178 {
179 end_rule_functor end(end_day(year),
180 end_month(year));
181 return end.get_date(year);
182 }
183 };
184
185
186
187
188
189
190} } //namespace boost::date_time
191
192
193#endif
194

source code of boost/boost/date_time/local_timezone_defs.hpp