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<div class="section">
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
<a name="date_time.examples.general_usage_examples"></a>General Usage Examples</h2></div></div></div>
<p>
The following provides some sample usage of dates.
See <a class="link" href="../gregorian.html" title="Gregorian">Date Programming</a>
for more details.
</p>
<pre class="programlisting"><span class="keyword">using namespace</span> boost::gregorian;
date weekstart(<span class="number">2002</span>,Feb,<span class="number">1</span>);
date weekend = weekstart + weeks(<span class="number">1</span>);
date d2 = d1 + days(<span class="number">5</span>);
date today = day_clock::local_day();
if (d2 >= today) {} <span class="comment">//date comparison operators</span>
date_period thisWeek(d1,d2);
<span class="keyword">if</span> (thisWeek.contains(today)) {}<span class="comment">//do something
//iterate and print the week</span>
day_iterator itr(weekstart);
<span class="keyword">while</span> (itr <= weekend) {
std::cout << (*itr) << std::endl;
++itr;
}
<span class="comment">//input streaming</span>
std::stringstream ss(<span class="string">"2004-Jan-1"</span>);
ss >> d3;
<span class="comment">//date generator functions</span>
date d5 = next_weekday(d4, Sunday); <span class="comment">//calculate Sunday following d4
//US labor day is first Monday in Sept</span>
<span class="keyword">typedef</span> nth_day_of_the_week_in_month nth_dow;
nth_dow labor_day(nth_dow::first,Monday, Sep);
<span class="comment">//calculate a specific date for 2004 from functor</span>
date d6 = labor_day.get_date(<span class="number">2004</span>);
</pre>
<p>
The following provides some example code using times.
See <a class="link" href="../posix_time.html" title="Posix Time">Time Programming</a>
for more details.
</p>
<pre class="programlisting"><span class="keyword">using namespace</span> boost::posix_time;
date d(<span class="number">2002</span>,Feb,<span class="number">1</span>); <span class="comment">//an arbitrary date</span>
ptime t1(d, hours(<span class="number">5</span>)+nanosec(<span class="number">100</span>)); <span class="comment">//date + time of day offset</span>
ptime t2 = t1 - minutes(<span class="number">4</span>)+seconds(<span class="number">2</span>);
ptime now = second_clock::local_time(); <span class="comment">//use the clock</span>
date today = now.date(); <span class="comment">//Get the date part out of the time</span>
date tomorrow = today + date_duration(<span class="number">1</span>);
ptime tomorrow_start(tomorrow); <span class="comment">//midnight
//input streaming</span>
std::stringstream ss(<span class="string">"2004-Jan-1 05:21:33.20"</span>);
ss >> t2;
<span class="comment">//starting at current time iterator adds by one hour</span>
time_iterator titr(now,hours(<span class="number">1</span>));
<span class="keyword">for</span> (; titr < tomorrow_start; ++titr) {
std::cout << (*titr) << std::endl;
}
</pre>
<p>
</p>
<p>
The following provides some example code using times.
See <a class="link" href="../local_time.html" title="Local Time">Local Time Programming</a>
for more details.
</p>
<pre class="programlisting">
<span class="keyword">using namespace</span> boost::local_time;
<span class="comment">//setup some timezones for creating and adjusting times
//first time zone uses the time zone file for regional timezone definitions</span>
tz_database tz_db;
tz_db.load_from_file(<span class="string">"date_time_zonespec.csv"</span>);
time_zone_ptr nyc_tz = tz_db.time_zone_from_region(<span class="string">"America/New_York"</span>);
<span class="comment">//This timezone uses a posix time zone string definition to create a time zone</span>
time_zone_ptr phx_tz(new posix_time_zone(<span class="string">"MST-07:00:00"</span>));
<span class="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)</span>
local_date_time phx_departure(date(<span class="number">2005</span>, Apr, <span class="number">2</span>), hours(<span class="number">23</span>), phx_tz,
local_date_time::NOT_DATE_TIME_ON_ERROR);
time_duration flight_length = hours(<span class="number">4</span>) + minutes(<span class="number">30</span>);
local_date_time phx_arrival = phx_departure + flight_length;
<span class="comment">//convert the phx time to a nyz time</span>
local_date_time nyc_arrival = phx_arrival.local_time_in(nyc_tz);
<span class="comment">//2005-Apr-03 06:30:00 EDT</span>
std::cout << nyc_arrival << std::endl;
</pre>
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<td align="right"><div class="copyright-footer">Copyright © 2001-2005 CrystalClear Software, Inc<p>Subject to the Boost Software License, Version 1.0. (See accompanying file
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