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- <?xml version="1.0" encoding="utf-8"?>
- <!DOCTYPE library PUBLIC "-//Boost//DTD BoostBook XML V1.0//EN"
- "../../../tools/boostbook/dtd/boostbook.dtd">
- <!-- Copyright (c) 2001-2005 CrystalClear Software, Inc.
- 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)
- -->
- <section id="date_time.examples.simple_time_zone">
- <title>Simple Time Zones</title>
- <para>
- Example usage of custom_time_zone as well as posix_time_zone.
- </para>
- <programlisting>
- <![CDATA[
- /* A simple example for using a custom_time_zone and a posix_time_zone.
- */
- #include "boost/date_time/local_time/local_time.hpp"
- #include <iostream>
- int
- main()
- {
- using namespace boost;
- using namespace local_time;
- using namespace gregorian;
- using posix_time::time_duration;
- /***** custom_time_zone *****/
-
- // create the dependent objects for a custom_time_zone
- time_zone_names tzn("Eastern Standard Time", "EST",
- "Eastern Daylight Time", "EDT");
- time_duration utc_offset(-5,0,0);
- dst_adjustment_offsets adj_offsets(time_duration(1,0,0),
- time_duration(2,0,0),
- time_duration(2,0,0));
- // rules for this zone are:
- // start on first Sunday of April at 2 am
- // end on last Sunday of October at 2 am
- // so we use a first_last_dst_rule
- first_day_of_the_week_in_month start_rule(Sunday, Apr);
- last_day_of_the_week_in_month end_rule(Sunday, Oct);
- shared_ptr<dst_calc_rule> nyc_rules(new first_last_dst_rule(start_rule,
- end_rule));
- // create more dependent objects for a non-dst custom_time_zone
- time_zone_names tzn2("Mountain Standard Time", "MST",
- "", ""); // no dst means empty dst strings
- time_duration utc_offset2(-7,0,0);
- dst_adjustment_offsets adj_offsets2(time_duration(0,0,0),
- time_duration(0,0,0),
- time_duration(0,0,0));
- // no dst means we need a null pointer to the rules
- shared_ptr<dst_calc_rule> phx_rules;
- // create the custom_time_zones
- time_zone_ptr nyc_1(new custom_time_zone(tzn, utc_offset,
- adj_offsets, nyc_rules));
- time_zone_ptr phx_1(new custom_time_zone(tzn2, utc_offset2,
- adj_offsets2, phx_rules));
- /***** posix_time_zone *****/
- // create posix_time_zones that are the duplicates of the
- // custom_time_zones created above. See posix_time_zone documentation
- // for details on full zone names.
- std::string nyc_string, phx_string;
- nyc_string = "EST-05:00:00EDT+01:00:00,M4.1.0/02:00:00,M10.5.0/02:00:00";
- // nyc_string = "EST-05EDT,M4.1.0,M10.5.0"; // shorter when defaults used
- phx_string = "MST-07"; // no-dst
- time_zone_ptr nyc_2(new posix_time_zone(nyc_string));
- time_zone_ptr phx_2(new posix_time_zone(phx_string));
-
- /***** show the sets are equal *****/
- std::cout << "The first zone is in daylight savings from:\n "
- << nyc_1->dst_local_start_time(2004) << " through "
- << nyc_1->dst_local_end_time(2004) << std::endl;
- std::cout << "The second zone is in daylight savings from:\n "
- << nyc_2->dst_local_start_time(2004) << " through "
- << nyc_2->dst_local_end_time(2004) << std::endl;
- std::cout << "The third zone (no daylight savings):\n "
- << phx_1->std_zone_abbrev() << " and "
- << phx_1->base_utc_offset() << std::endl;
- std::cout << "The fourth zone (no daylight savings):\n "
- << phx_2->std_zone_abbrev() << " and "
- << phx_2->base_utc_offset() << std::endl;
- return 0;
- }
- ]]>
- </programlisting>
- </section>
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