<?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.general_usage_examples"> <title>General Usage Examples</title> <para> The following provides some sample usage of dates. See <link linkend="date_time.gregorian">Date Programming</link> for more details. <programlisting><emphasis role="keyword">using namespace</emphasis> boost::gregorian; date weekstart(<emphasis role="number">2002</emphasis>,Feb,<emphasis role="number">1</emphasis>); date weekend = weekstart + week(<emphasis role="number">1</emphasis>); date d2 = d1 + days(<emphasis role="number">5</emphasis>); date today = day_clock::local_day(); if (d2 >= today) {} <emphasis role="comment">//date comparison operators</emphasis> date_period thisWeek(d1,d2); <emphasis role="keyword">if</emphasis> (thisWeek.contains(today)) {}<emphasis role="comment">//do something //iterate and print the week</emphasis> day_iterator itr(weekstart); <emphasis role="keyword">while</emphasis> (itr <= weekend) { std::cout << (*itr) << std::endl; ++itr; } <emphasis role="comment">//input streaming</emphasis> std::stringstream ss(<emphasis role="string">"2004-Jan-1"</emphasis>); ss >> d3; <emphasis role="comment">//date generator functions</emphasis> date d5 = next_weekday(d4, Sunday); <emphasis role="comment">//calculate Sunday following d4 //US labor day is first Monday in Sept</emphasis> nth_day_of_the_week_in_month labor_day(nth_dow::first,Monday, Sep); <emphasis role="comment">//calculate a specific date for 2004 from functor</emphasis> date d6 = labor_day.get_date(<emphasis role="number">2004</emphasis>); </programlisting> The following provides some example code using times. See <link linkend="date_time.posix_time">Time Programming</link> for more details. <programlisting><emphasis role="keyword">using namespace</emphasis> boost::posix_time; date d(<emphasis role="number">2002</emphasis>,Feb,<emphasis role="number">1</emphasis>); <emphasis role="comment">//an arbitrary date</emphasis> ptime t1(d, hours(<emphasis role="number">5</emphasis>)+nanosec(<emphasis role="number">100</emphasis>)); <emphasis role="comment">//date + time of day offset</emphasis> ptime t2 = t1 - minutes(<emphasis role="number">4</emphasis>)+seconds(<emphasis role="number">2</emphasis>); ptime now = second_clock::local_time(); <emphasis role="comment">//use the clock</emphasis> date today = now.date(); <emphasis role="comment">//Get the date part out of the time</emphasis> date tomorrow = today + date_duration(<emphasis role="number">1</emphasis>); ptime tomorrow_start(tomorrow); <emphasis role="comment">//midnight //input streaming</emphasis> std::stringstream ss(<emphasis role="string">"2004-Jan-1 05:21:33.20"</emphasis>); ss >> t2; <emphasis role="comment">//starting at current time iterator adds by one hour</emphasis> time_iterator titr(now,hours(<emphasis role="number">1</emphasis>)); <emphasis role="keyword">for</emphasis> (; titr < tomorrow_start; ++titr) { std::cout << (*titr) << std::endl; } </programlisting> </para> <para> The following provides some example code using times. See <link linkend="date_time.local_time">Local Time Programming</link> for more details. <programlisting> <emphasis role="keyword">using namespace</emphasis> boost::local_time; <emphasis role="comment">//setup some timezones for creating and adjusting times //first time zone uses the time zone file for regional timezone definitions</emphasis> tz_database tz_db; tz_db.load_from_file(<emphasis role="string">"date_time_zonespec.csv"</emphasis>); time_zone_ptr nyc_tz = tz_db.time_zone_from_region(<emphasis role="string">"America/New_York"</emphasis>); <emphasis role="comment">//This timezone uses a posix time zone string definition to create a time zone</emphasis> time_zone_ptr phx_tz(new posix_time_zone(<emphasis role="string">"MST-07:00:00"</emphasis>)); <emphasis role="comment">//local departure time in phoenix is 11 pm on April 2 2005 // Note that New York changes to daylight savings on Apr 3 at 2 am)</emphasis> local_date_time phx_departure(date(<emphasis role="number">2005</emphasis>, Apr, <emphasis role="number">2</emphasis>), hours(<emphasis role="number">23</emphasis>), phx_tz, local_date_time::NOT_DATE_TIME_ON_ERROR); time_duration flight_length = hours(<emphasis role="number">4</emphasis>) + minutes(<emphasis role="number">30</emphasis>); local_date_time phx_arrival = phx_departure + flight_length; <emphasis role="comment">//convert the phx time to a nyz time</emphasis> local_date_time nyc_arrival = phx_arrival.local_time_in(nyc_tz); <emphasis role="comment">//2005-Apr-03 06:30:00 EDT</emphasis> std::cout << nyc_arrival << std::endl; </programlisting> </para> </section>