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 | |
14 | namespace 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 | |