c++ - Convert Boost Ptime To EST UTC-5:00 -

i using following code current date time (mountain time)

const boost::posix_time::ptime = boost::posix_time::second_clock::local_time();      //in mountain time = 2013-apr-08 20:44:22 

now using following method conversion

ptime feedconnector::mountainttoeasternconversion(ptime colotime)  {        return boost::date_time::local_adjustor <ptime, -5, us_dst>::utc_to_local(colotime); }  

//this function suppose give me time in newyork (east standard time) , getting

2013-apr-08 16:44:22 

thsi time wrong suggestion going wrong ?

as far understand wrong time means has 1 hour difference expected, i.e. -4 hours instead of expected -5 hours. if yes, problem us_std type pointed last parameter of local_adjustor declaration. if specify no_dst instead of use_dst. code works expatiated , difference -5 hours. following code demonstrates (link online compiled version)

#include <boost/date_time/posix_time/posix_time.hpp> #include <boost/date_time/local_time_adjustor.hpp> #include <iostream>  int main(void) {    const boost::posix_time::ptime = boost::posix_time::second_clock::local_time();    const boost::posix_time::ptime adjusdst = boost::date_time::local_adjustor<boost::posix_time::ptime, -5, boost::posix_time::us_dst>::utc_to_local(now);    const boost::posix_time::ptime adjnodst = boost::date_time::local_adjustor<boost::posix_time::ptime, -5, boost::posix_time::no_dst>::utc_to_local(now);    std::cout << "now: " << << std::endl;    std::cout << "adjusdst: " << adjusdst << std::endl;    std::cout << "adjnodst: " << adjnodst << std::endl;    return 0; }