Files
date_time/example/local_time/seconds_since_epoch.cpp
Daniel James c9f634b1d4 Merged revisions 43211,43214-43219,43222-43225,43227-43238,43242,43244-43245,43249-43250,43257-43259,43261,43263,43265,43267-43268,43270-43271,43273,43275-43279,43284-43289,43291,43295,43297-43298,43304-43305,43307,43313,43315,43324,43326-43327,43331,43333,43339-43343,43345,43348,43350,43352-43353,43355-43356,43358,43360,43366-43367,43369-43370,43372-43376,43378-43389,43394,43396-43398,43400-43401,43403-43404,43406-43408,43413-43415,43417-43418,43420,43422-43423 via svnmerge from
https://svn.boost.org/svn/boost/trunk

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  r43417 | danieljames | 2008-02-26 22:04:55 +0000 (Tue, 26 Feb 2008) | 2 lines
  
  Fix a link to Boost.Bimap.
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  r43418 | danieljames | 2008-02-26 22:07:25 +0000 (Tue, 26 Feb 2008) | 2 lines
  
  Change another link that's no longer in the repository to link to the website.
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  r43422 | danieljames | 2008-02-27 18:51:14 +0000 (Wed, 27 Feb 2008) | 1 line
  
  Fix broken copyright urls. Fixes #1573.
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  r43423 | danieljames | 2008-02-27 19:22:01 +0000 (Wed, 27 Feb 2008) | 1 line
  
  Fix incorrect links to copyright of the form 'http:#www.boost.org
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[SVN r43425]
2008-02-27 20:00:24 +00:00

66 lines
2.2 KiB
C++

/* 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;
}
/* Copyright 2005: CrystalClear Software, Inc
* http://www.crystalclearsoftware.com
*
* 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)
*/