ceph/src/boost/libs/date_time/xmldoc/ex_simple_time_zone.xml

   1 <?xml version="1.0" encoding="utf-8"?>
   2 <!DOCTYPE library PUBLIC "-//Boost//DTD BoostBook XML V1.0//EN"
   3 "../../../tools/boostbook/dtd/boostbook.dtd">
   4
   5 <!-- Copyright (c) 2001-2005 CrystalClear Software, Inc.
   6      Subject to the Boost Software License, Version 1.0.
   7      (See accompanying file LICENSE_1_0.txt or  http://www.boost.org/LICENSE_1_0.txt)
   8 -->
   9
  10 <section id="date_time.examples.simple_time_zone">
  11   <title>Simple Time Zones</title>
  12
  13   <para>
  14     Example usage of custom_time_zone as well as posix_time_zone.
  15   </para>
  16   <programlisting>
  17     <![CDATA[
  18   /* A simple example for using a custom_time_zone and a posix_time_zone.
  19    */
  20
  21   #include "boost/date_time/local_time/local_time.hpp"
  22   #include <iostream>
  23
  24   int
  25   main()
  26   {
  27     using namespace boost;
  28     using namespace local_time;
  29     using namespace gregorian;
  30     using posix_time::time_duration;
  31
  32     /***** custom_time_zone *****/
  33
  34     // create the dependent objects for a custom_time_zone
  35     time_zone_names tzn("Eastern Standard Time", "EST",
  36                         "Eastern Daylight Time", "EDT");
  37     time_duration utc_offset(-5,0,0);
  38     dst_adjustment_offsets adj_offsets(time_duration(1,0,0),
  39                                        time_duration(2,0,0),
  40                                        time_duration(2,0,0));
  41     // rules for this zone are:
  42     // start on first Sunday of April at 2 am
  43     // end on last Sunday of October at 2 am
  44     // so we use a first_last_dst_rule
  45     first_day_of_the_week_in_month start_rule(Sunday, Apr);
  46     last_day_of_the_week_in_month    end_rule(Sunday, Oct);
  47     shared_ptr<dst_calc_rule> nyc_rules(new first_last_dst_rule(start_rule,
  48                                                                 end_rule));
  49     // create more dependent objects for a non-dst custom_time_zone
  50     time_zone_names tzn2("Mountain Standard Time", "MST",
  51                          "", ""); // no dst means empty dst strings
  52     time_duration utc_offset2(-7,0,0);
  53     dst_adjustment_offsets adj_offsets2(time_duration(0,0,0),
  54                                         time_duration(0,0,0),
  55                                         time_duration(0,0,0));
  56     // no dst means we need a null pointer to the rules
  57     shared_ptr<dst_calc_rule> phx_rules;
  58
  59     // create the custom_time_zones
  60     time_zone_ptr nyc_1(new custom_time_zone(tzn, utc_offset,
  61                                              adj_offsets, nyc_rules));
  62     time_zone_ptr phx_1(new custom_time_zone(tzn2, utc_offset2,
  63                                              adj_offsets2, phx_rules));
  64
  65     /***** posix_time_zone *****/
  66
  67     // create posix_time_zones that are the duplicates of the
  68     // custom_time_zones created above. See posix_time_zone documentation
  69     // for details on full zone names.
  70     std::string nyc_string, phx_string;
  71     nyc_string = "EST-05:00:00EDT+01:00:00,M4.1.0/02:00:00,M10.5.0/02:00:00";
  72     // nyc_string = "EST-05EDT,M4.1.0,M10.5.0"; // shorter when defaults used
  73     phx_string = "MST-07"; // no-dst
  74     time_zone_ptr nyc_2(new posix_time_zone(nyc_string));
  75     time_zone_ptr phx_2(new posix_time_zone(phx_string));
  76
  77
  78     /***** show the sets are equal *****/
  79
  80     std::cout << "The first zone is in daylight savings from:\n "
  81       << nyc_1->dst_local_start_time(2004) << " through "
  82       << nyc_1->dst_local_end_time(2004) << std::endl;
  83
  84     std::cout << "The second zone is in daylight savings from:\n "
  85       << nyc_2->dst_local_start_time(2004) << " through "
  86       << nyc_2->dst_local_end_time(2004) << std::endl;
  87
  88     std::cout << "The third zone (no daylight savings):\n "
  89       << phx_1->std_zone_abbrev() << " and "
  90       << phx_1->base_utc_offset() << std::endl;
  91
  92     std::cout << "The fourth zone (no daylight savings):\n "
  93       << phx_2->std_zone_abbrev() << " and "
  94       << phx_2->base_utc_offset() << std::endl;
  95
  96     return 0;
  97   }
  98     ]]>
  99   </programlisting>
 100 </section>