Boost datetime to formatted output modified from http://bit.ly/2VwaARa http://cpp.sh/6mp4m

boost_datetime_format.cpp

#include "boost/date_time/posix_time/posix_time.hpp"
#include <iostream>
#include <sstream>

std::string FormatTime(boost::posix_time::ptime now)
{
  using namespace boost::posix_time;
  static std::locale loc(std::wcout.getloc(),
                         new wtime_facet(L"%Y%m%d_%H%M%S"));

  std::stringstream wss;
  wss.imbue(loc);
  wss << now;
  return wss.str();
}

int main() {
  using namespace boost::posix_time;
  ptime now = second_clock::universal_time();

  std::string ws(FormatTime(now));
  std::cout << ws << std::endl;
  sleep(2);
  now = second_clock::universal_time();
  ws = FormatTime(now);
  std::cout << ws << std::endl;

}