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<div class="titlepage"><div><div><h2 class="title" style="clear: both">
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<a name="date_time.examples"></a>Examples</h2></div></div></div>
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<div class="toc"><dl class="toc">
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<dt><span class="section"><a href="examples.html#date_time.examples.dates_as_strings">Dates as Strings</a></span></dt>
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<dt><span class="section"><a href="examples.html#date_time.examples.days_alive">Days Alive</a></span></dt>
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<dt><span class="section"><a href="examples.html#date_time.examples.days_between_new_year">Days Between New Years</a></span></dt>
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<dt><span class="section"><a href="examples.html#date_time.examples.end_of_month_day">Last Day of the Months</a></span></dt>
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<dt><span class="section"><a href="examples.html#date_time.examples.localization">Localization Demonstration</a></span></dt>
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<dt><span class="section"><a href="examples.html#date_time.examples.date_period_calc">Date Period Calculations</a></span></dt>
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<dt><span class="section"><a href="examples.html#date_time.examples.print_holidays">Print Holidays</a></span></dt>
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<dt><span class="section"><a href="examples.html#date_time.examples.print_month">Print Month</a></span></dt>
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<dt><span class="section"><a href="examples.html#date_time.examples.month_add">Month Adding</a></span></dt>
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<dt><span class="section"><a href="examples.html#date_time.examples.time_math">Time Math</a></span></dt>
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<dt><span class="section"><a href="examples.html#date_time.examples.print_hours">Print Hours</a></span></dt>
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<dt><span class="section"><a href="examples.html#date_time.examples.local_utc_conversion">Local to UTC Conversion</a></span></dt>
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<dt><span class="section"><a href="examples.html#date_time.examples.time_periods">Time Periods</a></span></dt>
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<dt><span class="section"><a href="examples.html#date_time.examples.simple_time_zone">Simple Time Zones</a></span></dt>
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<dt><span class="section"><a href="examples.html#date_time.examples.calc_rules">Daylight Savings Calc Rules</a></span></dt>
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<dt><span class="section"><a href="examples.html#date_time.examples.flight">Flight Time Example</a></span></dt>
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<dt><span class="section"><a href="examples.html#date_time.examples.seconds_since_epoch">Seconds Since Epoch</a></span></dt>
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</dl></div>
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<div class="section">
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<div class="titlepage"><div><div><h3 class="title">
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<a name="date_time.examples.dates_as_strings"></a>Dates as Strings</h3></div></div></div>
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<p>
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Various parsing and output of strings.
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</p>
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<pre class="programlisting">
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/* The following is a simple example that shows conversion of dates
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* to and from a std::string.
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*
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* Expected output:
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* 2001-Oct-09
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* 2001-10-09
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* Tuesday October 9, 2001
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* An expected exception is next:
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* Exception: Month number is out of range 1..12
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*/
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#include "boost/date_time/gregorian/gregorian.hpp"
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#include <iostream>
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#include <string>
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int
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main()
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{
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using namespace boost::gregorian;
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try {
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// The following date is in ISO 8601 extended format (CCYY-MM-DD)
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std::string s("2001-10-9"); //2001-October-09
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date d(from_simple_string(s));
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std::cout << to_simple_string(d) << std::endl;
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//Read ISO Standard(CCYYMMDD) and output ISO Extended
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std::string ud("20011009"); //2001-Oct-09
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date d1(from_undelimited_string(ud));
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std::cout << to_iso_extended_string(d1) << std::endl;
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//Output the parts of the date - Tuesday October 9, 2001
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date::ymd_type ymd = d1.year_month_day();
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greg_weekday wd = d1.day_of_week();
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std::cout << wd.as_long_string() << " "
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<< ymd.month.as_long_string() << " "
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<< ymd.day << ", " << ymd.year
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<< std::endl;
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//Let's send in month 25 by accident and create an exception
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std::string bad_date("20012509"); //2001-??-09
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std::cout << "An expected exception is next: " << std::endl;
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date wont_construct(from_undelimited_string(bad_date));
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//use wont_construct so compiler doesn't complain, but you wont get here!
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std::cout << "oh oh, you shouldn't reach this line: "
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<< to_iso_string(wont_construct) << std::endl;
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}
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catch(std::exception& e) {
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std::cout << " Exception: " << e.what() << std::endl;
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}
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return 0;
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}
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</pre>
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</div>
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<div class="section">
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<div class="titlepage"><div><div><h3 class="title">
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<a name="date_time.examples.days_alive"></a>Days Alive</h3></div></div></div>
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<p>
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Calculate the number of days you have been living using durations and dates.
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</p>
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<pre class="programlisting">
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<code class="literal">
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<span class="comment">/* Short example that calculates the number of days since user was born.
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* Demonstrates comparisons of durations, use of the day_clock,
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* and parsing a date from a string.
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*/</span><span class="preprocessor">
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#include</span><span class="string"> "boost/date_time/gregorian/gregorian.hpp"</span><span class="preprocessor">
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#include</span><span class="special"> <</span><span class="identifier">iostream</span><span class="special">></span><span class="keyword">
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int</span><span class="identifier">
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main</span><span class="special">()</span><span class="special">
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{</span><span class="keyword">
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using</span><span class="keyword"> namespace</span><span class="identifier"> boost</span><span class="special">::</span><span class="identifier">gregorian</span><span class="special">;</span><span class="identifier">
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std</span><span class="special">::</span><span class="identifier">string</span><span class="identifier"> s</span><span class="special">;</span><span class="identifier">
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std</span><span class="special">::</span><span class="identifier">cout</span><span class="special"> <<</span><span class="string"> "Enter birth day YYYY-MM-DD (eg: 2002-02-01): "</span><span class="special">;</span><span class="identifier">
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std</span><span class="special">::</span><span class="identifier">cin</span><span class="special"> >></span><span class="identifier"> s</span><span class="special">;</span><span class="keyword">
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try</span><span class="special"> {</span><span class="identifier">
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date</span><span class="identifier"> birthday</span><span class="special">(</span><span class="identifier">from_simple_string</span><span class="special">(</span><span class="identifier">s</span><span class="special">));</span><span class="identifier">
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date</span><span class="identifier"> today</span><span class="special"> =</span><span class="identifier"> day_clock</span><span class="special">::</span><span class="identifier">local_day</span><span class="special">();</span><span class="identifier">
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days</span><span class="identifier"> days_alive</span><span class="special"> =</span><span class="identifier"> today</span><span class="special"> -</span><span class="identifier"> birthday</span><span class="special">;</span><span class="identifier">
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days</span><span class="identifier"> one_day</span><span class="special">(</span><span class="number">1</span><span class="special">);</span><span class="keyword">
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if</span><span class="special"> (</span><span class="identifier">days_alive</span><span class="special"> ==</span><span class="identifier"> one_day</span><span class="special">)</span><span class="special"> {</span><span class="identifier">
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std</span><span class="special">::</span><span class="identifier">cout</span><span class="special"> <<</span><span class="string"> "Born yesterday, very funny"</span><span class="special"> <<</span><span class="identifier"> std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span><span class="special">
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}</span><span class="keyword">
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else</span><span class="keyword"> if</span><span class="special"> (</span><span class="identifier">days_alive</span><span class="special"> <</span><span class="identifier"> days</span><span class="special">(</span><span class="number">0</span><span class="special">))</span><span class="special"> {</span><span class="identifier">
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std</span><span class="special">::</span><span class="identifier">cout</span><span class="special"> <<</span><span class="string"> "Not born yet, hmm: "</span><span class="special"> <<</span><span class="identifier"> days_alive</span><span class="special">.</span><span class="identifier">days</span><span class="special">()</span><span class="special">
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<<</span><span class="string"> " days"</span><span class="special"> <<</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span><span class="special">
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}</span><span class="keyword">
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else</span><span class="special"> {</span><span class="identifier">
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std</span><span class="special">::</span><span class="identifier">cout</span><span class="special"> <<</span><span class="string"> "Days alive: "</span><span class="special"> <<</span><span class="identifier"> days_alive</span><span class="special">.</span><span class="identifier">days</span><span class="special">()</span><span class="special"> <<</span><span class="identifier"> std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span><span class="special">
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||
}</span><span class="special">
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||
|
||
}</span><span class="keyword">
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||
catch</span><span class="special">(...)</span><span class="special"> {</span><span class="identifier">
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||
std</span><span class="special">::</span><span class="identifier">cout</span><span class="special"> <<</span><span class="string"> "Bad date entered: "</span><span class="special"> <<</span><span class="identifier"> s</span><span class="special"> <<</span><span class="identifier"> std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span><span class="special">
|
||
}</span><span class="keyword">
|
||
return</span><span class="number"> 0</span><span class="special">;</span><span class="special">
|
||
}</span>
|
||
</code>
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||
</pre>
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="date_time.examples.days_between_new_year"></a>Days Between New Years</h3></div></div></div>
|
||
<p>
|
||
Calculate the number of days till new years
|
||
</p>
|
||
<pre class="programlisting">
|
||
|
||
/* Provides a simple example of using a date_generator, and simple
|
||
* mathematical operatorations, to calculate the days since
|
||
* New Years day of this year, and days until next New Years day.
|
||
*
|
||
* Expected results:
|
||
* Adding together both durations will produce 366 (365 in a leap year).
|
||
*/
|
||
#include <iostream>
|
||
#include "boost/date_time/gregorian/gregorian.hpp"
|
||
|
||
int
|
||
main()
|
||
{
|
||
|
||
using namespace boost::gregorian;
|
||
|
||
date today = day_clock::local_day();
|
||
partial_date new_years_day(1,Jan);
|
||
//Subtract two dates to get a duration
|
||
days days_since_year_start = today - new_years_day.get_date(today.year());
|
||
std::cout << "Days since Jan 1: " << days_since_year_start.days()
|
||
<< std::endl;
|
||
|
||
days days_until_year_start = new_years_day.get_date(today.year()+1) - today;
|
||
std::cout << "Days until next Jan 1: " << days_until_year_start.days()
|
||
<< std::endl;
|
||
return 0;
|
||
};
|
||
|
||
|
||
</pre>
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="date_time.examples.end_of_month_day"></a>Last Day of the Months</h3></div></div></div>
|
||
<p>
|
||
Example that gets a month and a year from the user and finds the last day of each remaining month of that year.
|
||
</p>
|
||
<pre class="programlisting">
|
||
|
||
/* Simple program that finds the last day of the given month,
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||
* then displays the last day of every month left in the given year.
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||
*/
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||
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#include "boost/date_time/gregorian/gregorian.hpp"
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#include <iostream>
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||
|
||
int
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||
main()
|
||
{
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||
using namespace boost::gregorian;
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||
|
||
greg_year year(1400);
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||
greg_month month(1);
|
||
|
||
// get a month and a year from the user
|
||
try {
|
||
int y, m;
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||
std::cout << " Enter Year(ex: 2002): ";
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||
std::cin >> y;
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||
year = greg_year(y);
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std::cout << " Enter Month(1..12): ";
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std::cin >> m;
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||
month = greg_month(m);
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||
}
|
||
catch(bad_year by) {
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||
std::cout << "Invalid Year Entered: " << by.what() << '\n'
|
||
<< "Using minimum values for month and year." << std::endl;
|
||
}
|
||
catch(bad_month bm) {
|
||
std::cout << "Invalid Month Entered" << bm.what() << '\n'
|
||
<< "Using minimum value for month. " << std::endl;
|
||
}
|
||
|
||
date start_of_next_year(year+1, Jan, 1);
|
||
date d(year, month, 1);
|
||
|
||
// add another month to d until we enter the next year.
|
||
while (d < start_of_next_year){
|
||
std::cout << to_simple_string(d.end_of_month()) << std::endl;
|
||
d += months(1);
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
|
||
</pre>
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="date_time.examples.localization"></a>Localization Demonstration</h3></div></div></div>
|
||
<p>
|
||
The boost::date_time library provides the ability to create customized locale facets. Date ordering, language, seperators, and abbreviations can be customized.
|
||
</p>
|
||
<pre class="programlisting">
|
||
|
||
/* The following shows the creation of a facet for the output of
|
||
* dates in German (please forgive me for any errors in my German --
|
||
* I'm not a native speaker).
|
||
*/
|
||
|
||
#include "boost/date_time/gregorian/gregorian.hpp"
|
||
#include <iostream>
|
||
#include <algorithm>
|
||
|
||
/* Define a series of char arrays for short and long name strings
|
||
* to be associated with German date output (US names will be
|
||
* retrieved from the locale). */
|
||
const char* const de_short_month_names[] =
|
||
{
|
||
"Jan", "Feb", "Mar", "Apr", "Mai", "Jun",
|
||
"Jul", "Aug", "Sep", "Okt", "Nov", "Dez", "NAM"
|
||
};
|
||
const char* const de_long_month_names[] =
|
||
{
|
||
"Januar", "Februar", "Marz", "April", "Mai",
|
||
"Juni", "Juli", "August", "September", "Oktober",
|
||
"November", "Dezember", "NichtDerMonat"
|
||
};
|
||
const char* const de_long_weekday_names[] =
|
||
{
|
||
"Sonntag", "Montag", "Dienstag", "Mittwoch",
|
||
"Donnerstag", "Freitag", "Samstag"
|
||
};
|
||
const char* const de_short_weekday_names[] =
|
||
{
|
||
"Son", "Mon", "Die","Mit", "Don", "Fre", "Sam"
|
||
};
|
||
|
||
|
||
int main()
|
||
{
|
||
using namespace boost::gregorian;
|
||
|
||
// create some gregorian objects to output
|
||
date d1(2002, Oct, 1);
|
||
greg_month m = d1.month();
|
||
greg_weekday wd = d1.day_of_week();
|
||
|
||
// create a facet and a locale for German dates
|
||
date_facet* german_facet = new date_facet();
|
||
std::cout.imbue(std::locale(std::locale::classic(), german_facet));
|
||
|
||
// create the German name collections
|
||
date_facet::input_collection_type short_months, long_months,
|
||
short_weekdays, long_weekdays;
|
||
std::copy(&de_short_month_names[0], &de_short_month_names[11],
|
||
std::back_inserter(short_months));
|
||
std::copy(&de_long_month_names[0], &de_long_month_names[11],
|
||
std::back_inserter(long_months));
|
||
std::copy(&de_short_weekday_names[0], &de_short_weekday_names[6],
|
||
std::back_inserter(short_weekdays));
|
||
std::copy(&de_long_weekday_names[0], &de_long_weekday_names[6],
|
||
std::back_inserter(long_weekdays));
|
||
|
||
// replace the default names with ours
|
||
// NOTE: date_generators and special_values were not replaced as
|
||
// they are not used in this example
|
||
german_facet->short_month_names(short_months);
|
||
german_facet->long_month_names(long_months);
|
||
german_facet->short_weekday_names(short_weekdays);
|
||
german_facet->long_weekday_names(long_weekdays);
|
||
|
||
// output the date in German using short month names
|
||
german_facet->format("%d.%m.%Y");
|
||
std::cout << d1 << std::endl; //01.10.2002
|
||
|
||
german_facet->month_format("%B");
|
||
std::cout << m << std::endl; //Oktober
|
||
|
||
german_facet->weekday_format("%A");
|
||
std::cout << wd << std::endl; //Dienstag
|
||
|
||
|
||
// Output the same gregorian objects using US names
|
||
date_facet* us_facet = new date_facet();
|
||
std::cout.imbue(std::locale(std::locale::classic(), us_facet));
|
||
|
||
us_facet->format("%m/%d/%Y");
|
||
std::cout << d1 << std::endl; // 10/01/2002
|
||
|
||
// English names, iso order (year-month-day), '-' separator
|
||
us_facet->format("%Y-%b-%d");
|
||
std::cout << d1 << std::endl; // 2002-Oct-01
|
||
|
||
return 0;
|
||
|
||
}
|
||
|
||
</pre>
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="date_time.examples.date_period_calc"></a>Date Period Calculations</h3></div></div></div>
|
||
<p>
|
||
Calculates if a date is in an 'irregular' collection of periods using period calculation functions.
|
||
</p>
|
||
<pre class="programlisting">
|
||
|
||
/*
|
||
This example demonstrates a simple use of periods for the calculation
|
||
of date information.
|
||
|
||
The example calculates if a given date is a weekend or holiday
|
||
given an exclusion set. That is, each weekend or holiday is
|
||
entered into the set as a time interval. Then if a given date
|
||
is contained within any of the intervals it is considered to
|
||
be within the exclusion set and hence is a offtime.
|
||
|
||
Output:
|
||
Number Excluded Periods: 5
|
||
20020202/20020203
|
||
20020209/20020210
|
||
20020212/20020212
|
||
20020216/20020217
|
||
In Exclusion Period: 20020216 --> 20020216/20020217
|
||
20020223/20020224
|
||
|
||
*/
|
||
|
||
|
||
#include "boost/date_time/gregorian/gregorian.hpp"
|
||
#include <set>
|
||
#include <algorithm>
|
||
#include <iostream>
|
||
|
||
typedef std::set<boost::gregorian::date_period> date_period_set;
|
||
|
||
//Simple population of the exclusion set
|
||
date_period_set
|
||
generateExclusion()
|
||
{
|
||
using namespace boost::gregorian;
|
||
date_period periods_array[] =
|
||
{ date_period(date(2002,Feb,2), date(2002,Feb,4)),//weekend of 2nd-3rd
|
||
date_period(date(2002,Feb,9), date(2002,Feb,11)),
|
||
date_period(date(2002,Feb,16), date(2002,Feb,18)),
|
||
date_period(date(2002,Feb,23), date(2002,Feb,25)),
|
||
date_period(date(2002,Feb,12), date(2002,Feb,13))//a random holiday 2-12
|
||
};
|
||
const int num_periods = sizeof(periods_array)/sizeof(date_period);
|
||
|
||
date_period_set ps;
|
||
//insert the periods in the set
|
||
std::insert_iterator<date_period_set> itr(ps, ps.begin());
|
||
std::copy(periods_array, periods_array+num_periods, itr );
|
||
return ps;
|
||
|
||
}
|
||
|
||
|
||
int main()
|
||
{
|
||
using namespace boost::gregorian;
|
||
|
||
date_period_set ps = generateExclusion();
|
||
std::cout << "Number Excluded Periods: " << ps.size() << std::endl;
|
||
|
||
date d(2002,Feb,16);
|
||
date_period_set::const_iterator i = ps.begin();
|
||
//print the periods, check for containment
|
||
for (;i != ps.end(); i++) {
|
||
std::cout << to_iso_string(*i) << std::endl;
|
||
//if date is in exclusion period then print it
|
||
if (i->contains(d)) {
|
||
std::cout << "In Exclusion Period: "
|
||
<< to_iso_string(d) << " --> " << to_iso_string(*i)
|
||
<< std::endl;
|
||
}
|
||
}
|
||
|
||
return 0;
|
||
|
||
}
|
||
|
||
|
||
</pre>
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="date_time.examples.print_holidays"></a>Print Holidays</h3></div></div></div>
|
||
<p>
|
||
This is an example of using functors to define a holiday schedule
|
||
</p>
|
||
<pre class="programlisting">
|
||
|
||
|
||
/* Generate a set of dates using a collection of date generators
|
||
* Output looks like:
|
||
* Enter Year: 2002
|
||
* 2002-Jan-01 [Tue]
|
||
* 2002-Jan-21 [Mon]
|
||
* 2002-Feb-12 [Tue]
|
||
* 2002-Jul-04 [Thu]
|
||
* 2002-Sep-02 [Mon]
|
||
* 2002-Nov-28 [Thu]
|
||
* 2002-Dec-25 [Wed]
|
||
* Number Holidays: 7
|
||
*/
|
||
|
||
#include "boost/date_time/gregorian/gregorian.hpp"
|
||
#include <algorithm>
|
||
#include <functional>
|
||
#include <vector>
|
||
#include <iostream>
|
||
#include <set>
|
||
|
||
void
|
||
print_date(boost::gregorian::date d)
|
||
{
|
||
using namespace boost::gregorian;
|
||
#if defined(BOOST_DATE_TIME_NO_LOCALE)
|
||
std::cout << to_simple_string(d) << " [" << d.day_of_week() << "]\n";
|
||
#else
|
||
std::cout << d << " [" << d.day_of_week() << "]\n";
|
||
#endif
|
||
}
|
||
|
||
|
||
int
|
||
main() {
|
||
|
||
std::cout << "Enter Year: ";
|
||
int year;
|
||
std::cin >> year;
|
||
|
||
using namespace boost::gregorian;
|
||
|
||
//define a collection of holidays fixed by month and day
|
||
std::vector<year_based_generator*> holidays;
|
||
holidays.push_back(new partial_date(1,Jan)); //Western New Year
|
||
holidays.push_back(new partial_date(4,Jul)); //US Independence Day
|
||
holidays.push_back(new partial_date(25, Dec));//Christmas day
|
||
|
||
|
||
//define a shorthand for the nth_day_of_the_week_in_month function object
|
||
typedef nth_day_of_the_week_in_month nth_dow;
|
||
|
||
//US labor day
|
||
holidays.push_back(new nth_dow(nth_dow::first, Monday, Sep));
|
||
//MLK Day
|
||
holidays.push_back(new nth_dow(nth_dow::third, Monday, Jan));
|
||
//Pres day
|
||
holidays.push_back(new nth_dow(nth_dow::second, Tuesday, Feb));
|
||
//Thanksgiving
|
||
holidays.push_back(new nth_dow(nth_dow::fourth, Thursday, Nov));
|
||
|
||
typedef std::set<date> date_set;
|
||
date_set all_holidays;
|
||
|
||
for(std::vector<year_based_generator*>::iterator it = holidays.begin();
|
||
it != holidays.end(); ++it)
|
||
{
|
||
all_holidays.insert((*it)->get_date(year));
|
||
}
|
||
|
||
//print the holidays to the screen
|
||
std::for_each(all_holidays.begin(), all_holidays.end(), print_date);
|
||
std::cout << "Number Holidays: " << all_holidays.size() << std::endl;
|
||
|
||
return 0;
|
||
}
|
||
|
||
|
||
</pre>
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="date_time.examples.print_month"></a>Print Month</h3></div></div></div>
|
||
<p>
|
||
Simple utility to print out days of the month with the days of a month. Demontstrates date iteration (date_time::date_itr).
|
||
</p>
|
||
<pre class="programlisting">
|
||
|
||
/* This example prints all the dates in a month. It demonstrates
|
||
* the use of iterators as well as functions of the gregorian_calendar
|
||
*
|
||
* Output:
|
||
* Enter Year: 2002
|
||
* Enter Month(1..12): 2
|
||
* 2002-Feb-01 [Fri]
|
||
* 2002-Feb-02 [Sat]
|
||
* 2002-Feb-03 [Sun]
|
||
* 2002-Feb-04 [Mon]
|
||
* 2002-Feb-05 [Tue]
|
||
* 2002-Feb-06 [Wed]
|
||
* 2002-Feb-07 [Thu]
|
||
*/
|
||
|
||
#include "boost/date_time/gregorian/gregorian.hpp"
|
||
#include <iostream>
|
||
|
||
int
|
||
main()
|
||
{
|
||
std::cout << "Enter Year: ";
|
||
int year, month;
|
||
std::cin >> year;
|
||
std::cout << "Enter Month(1..12): ";
|
||
std::cin >> month;
|
||
|
||
using namespace boost::gregorian;
|
||
try {
|
||
//Use the calendar to get the last day of the month
|
||
int eom_day = gregorian_calendar::end_of_month_day(year,month);
|
||
date endOfMonth(year,month,eom_day);
|
||
|
||
//construct an iterator starting with firt day of the month
|
||
day_iterator ditr(date(year,month,1));
|
||
//loop thru the days and print each one
|
||
for (; ditr <= endOfMonth; ++ditr) {
|
||
#if defined(BOOST_DATE_TIME_NO_LOCALE)
|
||
std::cout << to_simple_string(*ditr) << " ["
|
||
#else
|
||
std::cout << *ditr << " ["
|
||
#endif
|
||
<< ditr->day_of_week() << "]"
|
||
<< std::endl;
|
||
}
|
||
}
|
||
catch(std::exception& e) {
|
||
|
||
std::cout << "Error bad date, check your entry: \n"
|
||
<< " Details: " << e.what() << std::endl;
|
||
}
|
||
return 0;
|
||
}
|
||
|
||
|
||
</pre>
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="date_time.examples.month_add"></a>Month Adding</h3></div></div></div>
|
||
<p>
|
||
Adding a month to a day without the use of iterators.
|
||
</p>
|
||
<pre class="programlisting">
|
||
|
||
/* Simple program that uses the gregorian calendar to progress by exactly
|
||
* one month, irregardless of how many days are in that month.
|
||
*
|
||
* This method can be used as an alternative to iterators
|
||
*/
|
||
|
||
#include "boost/date_time/gregorian/gregorian.hpp"
|
||
#include <iostream>
|
||
|
||
int
|
||
main()
|
||
{
|
||
|
||
using namespace boost::gregorian;
|
||
|
||
date d = day_clock::local_day();
|
||
add_month mf(1);
|
||
date d2 = d + mf.get_offset(d);
|
||
std::cout << "Today is: " << to_simple_string(d) << ".\n"
|
||
<< "One month from today will be: " << to_simple_string(d2)
|
||
<< std::endl;
|
||
|
||
return 0;
|
||
}
|
||
|
||
</pre>
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="date_time.examples.time_math"></a>Time Math</h3></div></div></div>
|
||
<p>
|
||
Various types of calculations with times and time durations.
|
||
</p>
|
||
<pre class="programlisting">
|
||
|
||
/* Some simple examples of constructing and calculating with times
|
||
* Output:
|
||
* 2002-Feb-01 00:00:00 - 2002-Feb-01 05:04:02.001000000 = -5:04:02.001000000
|
||
*/
|
||
|
||
#include "boost/date_time/posix_time/posix_time.hpp"
|
||
#include <iostream>
|
||
|
||
int
|
||
main()
|
||
{
|
||
using namespace boost::posix_time;
|
||
using namespace boost::gregorian;
|
||
|
||
date d(2002,Feb,1); //an arbitrary date
|
||
//construct a time by adding up some durations durations
|
||
ptime t1(d, hours(5)+minutes(4)+seconds(2)+millisec(1));
|
||
//construct a new time by subtracting some times
|
||
ptime t2 = t1 - hours(5)- minutes(4)- seconds(2)- millisec(1);
|
||
//construct a duration by taking the difference between times
|
||
time_duration td = t2 - t1;
|
||
|
||
std::cout << to_simple_string(t2) << " - "
|
||
<< to_simple_string(t1) << " = "
|
||
<< to_simple_string(td) << std::endl;
|
||
|
||
return 0;
|
||
}
|
||
|
||
</pre>
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="date_time.examples.print_hours"></a>Print Hours</h3></div></div></div>
|
||
<p>
|
||
Demonstrate time iteration, clock retrieval, and simple calculation.
|
||
</p>
|
||
<pre class="programlisting">
|
||
|
||
/* Print the remaining hours of the day
|
||
* Uses the clock to get the local time
|
||
* Use an iterator to iterate over the remaining hours
|
||
* Retrieve the date part from a time
|
||
*
|
||
* Expected Output something like:
|
||
*
|
||
* 2002-Mar-08 16:30:59
|
||
* 2002-Mar-08 17:30:59
|
||
* 2002-Mar-08 18:30:59
|
||
* 2002-Mar-08 19:30:59
|
||
* 2002-Mar-08 20:30:59
|
||
* 2002-Mar-08 21:30:59
|
||
* 2002-Mar-08 22:30:59
|
||
* 2002-Mar-08 23:30:59
|
||
* Time left till midnight: 07:29:01
|
||
*/
|
||
|
||
#include "boost/date_time/posix_time/posix_time.hpp"
|
||
#include <iostream>
|
||
|
||
int
|
||
main()
|
||
{
|
||
using namespace boost::posix_time;
|
||
using namespace boost::gregorian;
|
||
|
||
//get the current time from the clock -- one second resolution
|
||
ptime now = second_clock::local_time();
|
||
//Get the date part out of the time
|
||
date today = now.date();
|
||
date tommorrow = today + days(1);
|
||
ptime tommorrow_start(tommorrow); //midnight
|
||
|
||
//iterator adds by one hour
|
||
time_iterator titr(now,hours(1));
|
||
for (; titr < tommorrow_start; ++titr) {
|
||
std::cout << to_simple_string(*titr) << std::endl;
|
||
}
|
||
|
||
time_duration remaining = tommorrow_start - now;
|
||
std::cout << "Time left till midnight: "
|
||
<< to_simple_string(remaining) << std::endl;
|
||
return 0;
|
||
}
|
||
|
||
|
||
</pre>
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="date_time.examples.local_utc_conversion"></a>Local to UTC Conversion</h3></div></div></div>
|
||
<p>
|
||
Demonstrate utc to local and local to utc calculations including dst.
|
||
</p>
|
||
<pre class="programlisting">
|
||
|
||
|
||
/* Demonstrate conversions between a local time and utc
|
||
* Output:
|
||
*
|
||
* UTC <--> New York while DST is NOT active (5 hours)
|
||
* 2001-Dec-31 19:00:00 in New York is 2002-Jan-01 00:00:00 UTC time
|
||
* 2002-Jan-01 00:00:00 UTC is 2001-Dec-31 19:00:00 New York time
|
||
*
|
||
* UTC <--> New York while DST is active (4 hours)
|
||
* 2002-May-31 20:00:00 in New York is 2002-Jun-01 00:00:00 UTC time
|
||
* 2002-Jun-01 00:00:00 UTC is 2002-May-31 20:00:00 New York time
|
||
*
|
||
* UTC <--> Arizona (7 hours)
|
||
* 2002-May-31 17:00:00 in Arizona is 2002-Jun-01 00:00:00 UTC time
|
||
*/
|
||
|
||
#include "boost/date_time/posix_time/posix_time.hpp"
|
||
#include "boost/date_time/local_time_adjustor.hpp"
|
||
#include "boost/date_time/c_local_time_adjustor.hpp"
|
||
#include <iostream>
|
||
|
||
int
|
||
main()
|
||
{
|
||
using namespace boost::posix_time;
|
||
using namespace boost::gregorian;
|
||
|
||
//This local adjustor depends on the machine TZ settings-- highly dangerous!
|
||
typedef boost::date_time::c_local_adjustor<ptime> local_adj;
|
||
ptime t10(date(2002,Jan,1), hours(7));
|
||
ptime t11 = local_adj::utc_to_local(t10);
|
||
std::cout << "UTC <--> Zone base on TZ setting" << std::endl;
|
||
std::cout << to_simple_string(t11) << " in your TZ is "
|
||
<< to_simple_string(t10) << " UTC time "
|
||
<< std::endl;
|
||
time_duration td = t11 - t10;
|
||
std::cout << "A difference of: "
|
||
<< to_simple_string(td) << std::endl;
|
||
|
||
|
||
//eastern timezone is utc-5
|
||
typedef boost::date_time::local_adjustor<ptime, -5, us_dst> us_eastern;
|
||
|
||
ptime t1(date(2001,Dec,31), hours(19)); //5 hours b/f midnight NY time
|
||
|
||
std::cout << "\nUTC <--> New York while DST is NOT active (5 hours)"
|
||
<< std::endl;
|
||
ptime t2 = us_eastern::local_to_utc(t1);
|
||
std::cout << to_simple_string(t1) << " in New York is "
|
||
<< to_simple_string(t2) << " UTC time "
|
||
<< std::endl;
|
||
|
||
ptime t3 = us_eastern::utc_to_local(t2);//back should be the same
|
||
std::cout << to_simple_string(t2) << " UTC is "
|
||
<< to_simple_string(t3) << " New York time "
|
||
<< "\n\n";
|
||
|
||
ptime t4(date(2002,May,31), hours(20)); //4 hours b/f midnight NY time
|
||
std::cout << "UTC <--> New York while DST is active (4 hours)" << std::endl;
|
||
ptime t5 = us_eastern::local_to_utc(t4);
|
||
std::cout << to_simple_string(t4) << " in New York is "
|
||
<< to_simple_string(t5) << " UTC time "
|
||
<< std::endl;
|
||
|
||
ptime t6 = us_eastern::utc_to_local(t5);//back should be the same
|
||
std::cout << to_simple_string(t5) << " UTC is "
|
||
<< to_simple_string(t6) << " New York time "
|
||
<< "\n" << std::endl;
|
||
|
||
|
||
//Arizona timezone is utc-7 with no dst
|
||
typedef boost::date_time::local_adjustor<ptime, -7, no_dst> us_arizona;
|
||
|
||
ptime t7(date(2002,May,31), hours(17));
|
||
std::cout << "UTC <--> Arizona (7 hours)" << std::endl;
|
||
ptime t8 = us_arizona::local_to_utc(t7);
|
||
std::cout << to_simple_string(t7) << " in Arizona is "
|
||
<< to_simple_string(t8) << " UTC time "
|
||
<< std::endl;
|
||
|
||
return 0;
|
||
}
|
||
|
||
|
||
</pre>
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="date_time.examples.time_periods"></a>Time Periods</h3></div></div></div>
|
||
<p>
|
||
Demonstrate some simple uses of time periods.
|
||
</p>
|
||
<pre class="programlisting">
|
||
|
||
|
||
/* Some simple examples of constructing and calculating with times
|
||
* Returns:
|
||
* [2002-Feb-01 00:00:00/2002-Feb-01 23:59:59.999999999]
|
||
* contains 2002-Feb-01 03:00:05
|
||
* [2002-Feb-01 00:00:00/2002-Feb-01 23:59:59.999999999]
|
||
* intersected with
|
||
* [2002-Feb-01 00:00:00/2002-Feb-01 03:00:04.999999999]
|
||
* is
|
||
* [2002-Feb-01 00:00:00/2002-Feb-01 03:00:04.999999999]
|
||
*/
|
||
|
||
#include "boost/date_time/posix_time/posix_time.hpp"
|
||
#include <iostream>
|
||
|
||
using namespace boost::posix_time;
|
||
using namespace boost::gregorian;
|
||
|
||
//Create a simple period class to contain all the times in a day
|
||
class day_period : public time_period
|
||
{
|
||
public:
|
||
day_period(date d) : time_period(ptime(d),//midnight
|
||
ptime(d,hours(24)))
|
||
{}
|
||
|
||
};
|
||
|
||
int
|
||
main()
|
||
{
|
||
|
||
date d(2002,Feb,1); //an arbitrary date
|
||
//a period that represents a day
|
||
day_period dp(d);
|
||
ptime t(d, hours(3)+seconds(5)); //an arbitray time on that day
|
||
if (dp.contains(t)) {
|
||
std::cout << to_simple_string(dp) << " contains "
|
||
<< to_simple_string(t) << std::endl;
|
||
}
|
||
//a period that represents part of the day
|
||
time_period part_of_day(ptime(d, hours(0)), t);
|
||
//intersect the 2 periods and print the results
|
||
if (part_of_day.intersects(dp)) {
|
||
time_period result = part_of_day.intersection(dp);
|
||
std::cout << to_simple_string(dp) << " intersected with\n"
|
||
<< to_simple_string(part_of_day) << " is \n"
|
||
<< to_simple_string(result) << std::endl;
|
||
}
|
||
|
||
|
||
return 0;
|
||
}
|
||
|
||
|
||
</pre>
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="date_time.examples.simple_time_zone"></a>Simple Time Zones</h3></div></div></div>
|
||
<p>
|
||
Example usage of custom_time_zone as well as posix_time_zone.
|
||
</p>
|
||
<pre class="programlisting">
|
||
|
||
/* 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;
|
||
}
|
||
|
||
</pre>
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="date_time.examples.calc_rules"></a>Daylight Savings Calc Rules</h3></div></div></div>
|
||
<p>
|
||
Example of creating various Daylight Savings Calc Rule objects.
|
||
</p>
|
||
<pre class="programlisting">
|
||
|
||
/* A simple example for creating various dst_calc_rule instances
|
||
*/
|
||
|
||
#include "boost/date_time/gregorian/gregorian.hpp"
|
||
#include "boost/date_time/local_time/local_time.hpp"
|
||
#include <iostream>
|
||
|
||
int
|
||
main()
|
||
{
|
||
using namespace boost;
|
||
using namespace local_time;
|
||
using namespace gregorian;
|
||
|
||
/***** create the necessary date_generator objects *****/
|
||
// starting generators
|
||
first_day_of_the_week_in_month fd_start(Sunday, May);
|
||
last_day_of_the_week_in_month ld_start(Sunday, May);
|
||
nth_day_of_the_week_in_month nkd_start(nth_day_of_the_week_in_month::third,
|
||
Sunday, May);
|
||
partial_date pd_start(1, May);
|
||
// ending generators
|
||
first_day_of_the_week_in_month fd_end(Sunday, Oct);
|
||
last_day_of_the_week_in_month ld_end(Sunday, Oct);
|
||
nth_day_of_the_week_in_month nkd_end(nth_day_of_the_week_in_month::third,
|
||
Sunday, Oct);
|
||
partial_date pd_end(31, Oct);
|
||
|
||
/***** create the various dst_calc_rule objects *****/
|
||
dst_calc_rule_ptr pdr(new partial_date_dst_rule(pd_start, pd_end));
|
||
dst_calc_rule_ptr flr(new first_last_dst_rule(fd_start, ld_end));
|
||
dst_calc_rule_ptr llr(new last_last_dst_rule(ld_start, ld_end));
|
||
dst_calc_rule_ptr nlr(new nth_last_dst_rule(nkd_start, ld_end));
|
||
dst_calc_rule_ptr ndr(new nth_day_of_the_week_in_month_dst_rule(nkd_start,
|
||
nkd_end));
|
||
|
||
return 0;
|
||
}
|
||
|
||
|
||
</pre>
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="date_time.examples.flight"></a>Flight Time Example</h3></div></div></div>
|
||
<p>This example shows a program that calculates the arrival time of a plane that flys from Phoenix to New York. During the flight New York shifts into daylight savings time (Phoenix doesn't because Arizona doesn't use dst).</p>
|
||
<pre class="programlisting">
|
||
<code class="literal">
|
||
<span class="preprocessor">#include</span><span class="string"> "boost/date_time/local_time/local_time.hpp"</span><span class="preprocessor">
|
||
#include</span><span class="special"> <</span><span class="identifier">iostream</span><span class="special">></span><span class="comment">
|
||
|
||
/* This example shows a program that calculates the arrival time of a plane
|
||
* that flys from Phoenix to New York. During the flight New York shifts
|
||
* into daylight savings time (Phoenix doesn't because Arizona doesn't use
|
||
* dst).
|
||
*
|
||
*
|
||
*/</span><span class="keyword">
|
||
|
||
int</span><span class="identifier"> main</span><span class="special">()</span><span class="special">
|
||
{</span><span class="keyword">
|
||
using</span><span class="keyword"> namespace</span><span class="identifier"> boost</span><span class="special">::</span><span class="identifier">gregorian</span><span class="special">;</span><span class="keyword">
|
||
using</span><span class="keyword"> namespace</span><span class="identifier"> boost</span><span class="special">::</span><span class="identifier">local_time</span><span class="special">;</span><span class="keyword">
|
||
using</span><span class="keyword"> namespace</span><span class="identifier"> boost</span><span class="special">::</span><span class="identifier">posix_time</span><span class="special">;</span><span class="comment">
|
||
|
||
|
||
//setup some timezones for creating and adjusting local times
|
||
//This user editable file can be found in libs/date_time/data.
|
||
</span><span class="identifier"> tz_database</span><span class="identifier"> tz_db</span><span class="special">;</span><span class="identifier">
|
||
tz_db</span><span class="special">.</span><span class="identifier">load_from_file</span><span class="special">(</span><span class="string">"date_time_zonespec.csv"</span><span class="special">);</span><span class="identifier">
|
||
time_zone_ptr</span><span class="identifier"> nyc_tz</span><span class="special"> =</span><span class="identifier"> tz_db</span><span class="special">.</span><span class="identifier">time_zone_from_region</span><span class="special">(</span><span class="string">"America/New_York"</span><span class="special">);</span><span class="comment">
|
||
//Use a
|
||
</span><span class="identifier"> time_zone_ptr</span><span class="identifier"> phx_tz</span><span class="special">(</span><span class="keyword">new</span><span class="identifier"> posix_time_zone</span><span class="special">(</span><span class="string">"MST-07:00:00"</span><span class="special">));</span><span class="comment">
|
||
|
||
//local departure time in phoenix is 11 pm on april 2 2005
|
||
// (ny changes to dst on apr 3 at 2 am)
|
||
</span><span class="identifier"> local_date_time</span><span class="identifier"> phx_departure</span><span class="special">(</span><span class="identifier">date</span><span class="special">(</span><span class="number">2005</span><span class="special">,</span><span class="identifier"> Apr</span><span class="special">,</span><span class="number"> 2</span><span class="special">),</span><span class="identifier"> hours</span><span class="special">(</span><span class="number">23</span><span class="special">),</span><span class="identifier">
|
||
phx_tz</span><span class="special">,</span><span class="identifier">
|
||
local_date_time</span><span class="special">::</span><span class="identifier">NOT_DATE_TIME_ON_ERROR</span><span class="special">);</span><span class="identifier">
|
||
|
||
time_duration</span><span class="identifier"> flight_length</span><span class="special"> =</span><span class="identifier"> hours</span><span class="special">(</span><span class="number">4</span><span class="special">)</span><span class="special"> +</span><span class="identifier"> minutes</span><span class="special">(</span><span class="number">30</span><span class="special">);</span><span class="identifier">
|
||
local_date_time</span><span class="identifier"> phx_arrival</span><span class="special"> =</span><span class="identifier"> phx_departure</span><span class="special"> +</span><span class="identifier"> flight_length</span><span class="special">;</span><span class="identifier">
|
||
local_date_time</span><span class="identifier"> nyc_arrival</span><span class="special"> =</span><span class="identifier"> phx_arrival</span><span class="special">.</span><span class="identifier">local_time_in</span><span class="special">(</span><span class="identifier">nyc_tz</span><span class="special">);</span><span class="identifier">
|
||
|
||
std</span><span class="special">::</span><span class="identifier">cout</span><span class="special"> <<</span><span class="string"> "departure phx time: "</span><span class="special"> <<</span><span class="identifier"> phx_departure</span><span class="special"> <<</span><span class="identifier"> std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span><span class="identifier">
|
||
std</span><span class="special">::</span><span class="identifier">cout</span><span class="special"> <<</span><span class="string"> "arrival phx time: "</span><span class="special"> <<</span><span class="identifier"> phx_arrival</span><span class="special"> <<</span><span class="identifier"> std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span><span class="identifier">
|
||
std</span><span class="special">::</span><span class="identifier">cout</span><span class="special"> <<</span><span class="string"> "arrival nyc time: "</span><span class="special"> <<</span><span class="identifier"> nyc_arrival</span><span class="special"> <<</span><span class="identifier"> std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span><span class="special">
|
||
|
||
}</span>
|
||
</code>
|
||
</pre>
|
||
</div>
|
||
<div class="section">
|
||
<div class="titlepage"><div><div><h3 class="title">
|
||
<a name="date_time.examples.seconds_since_epoch"></a>Seconds Since Epoch</h3></div></div></div>
|
||
<p>
|
||
Example of calculating seconds elapsed since epoch (1970-Jan-1) using local_date_time.
|
||
</p>
|
||
<pre class="programlisting">
|
||
|
||
/* This example demonstrates the use of the time zone database and
|
||
* local time to calculate the number of seconds since the UTC
|
||
* time_t epoch 1970-01-01 00:00:00. Note that the selected timezone
|
||
* could be any timezone supported in the time zone database file which
|
||
* can be modified and updated as needed by the user.
|
||
*
|
||
* To solve this problem the following steps are required:
|
||
* 1) Get a timezone from the tz database for the local time
|
||
* 2) Construct a local time using the timezone
|
||
* 3) Construct a posix_time::ptime for the time_t epoch time
|
||
* 4) Convert the local_time to utc and subtract the epoch time
|
||
*
|
||
*/
|
||
|
||
#include "boost/date_time/local_time/local_time.hpp"
|
||
#include <iostream>
|
||
|
||
int main()
|
||
{
|
||
using namespace boost::gregorian;
|
||
using namespace boost::local_time;
|
||
using namespace boost::posix_time;
|
||
|
||
tz_database tz_db;
|
||
try {
|
||
tz_db.load_from_file("../data/date_time_zonespec.csv");
|
||
}catch(data_not_accessible dna) {
|
||
std::cerr << "Error with time zone data file: " << dna.what() << std::endl;
|
||
exit(EXIT_FAILURE);
|
||
}catch(bad_field_count bfc) {
|
||
std::cerr << "Error with time zone data file: " << bfc.what() << std::endl;
|
||
exit(EXIT_FAILURE);
|
||
}
|
||
|
||
time_zone_ptr nyc_tz = tz_db.time_zone_from_region("America/New_York");
|
||
date in_date(2004,10,04);
|
||
time_duration td(12,14,32);
|
||
// construct with local time value
|
||
// create not-a-date-time if invalid (eg: in dst transition)
|
||
local_date_time nyc_time(in_date,
|
||
td,
|
||
nyc_tz,
|
||
local_date_time::NOT_DATE_TIME_ON_ERROR);
|
||
|
||
std::cout << nyc_time << std::endl;
|
||
|
||
ptime time_t_epoch(date(1970,1,1));
|
||
std::cout << time_t_epoch << std::endl;
|
||
|
||
// first convert nyc_time to utc via the utc_time()
|
||
// call and subtract the ptime.
|
||
time_duration diff = nyc_time.utc_time() - time_t_epoch;
|
||
|
||
//Expected 1096906472
|
||
std::cout << "Seconds diff: " << diff.total_seconds() << std::endl;
|
||
|
||
}
|
||
|
||
</pre>
|
||
</div>
|
||
</div>
|
||
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
|
||
<td align="left"></td>
|
||
<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
|
||
<code class="filename">LICENSE_1_0.txt</code> or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)</p>
|
||
</div></td>
|
||
</tr></table>
|
||
<hr>
|
||
<div class="spirit-nav">
|
||
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|
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|
||
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