I've found the Date Time library incredibly useful for dealing with timestamps, but I can't seem to get the output formatted the way I want. I've followed the example for the Date Time IO Tutorial (http://www.boost.org/doc/libs/1_39_0/doc/html/date_time/date_time_io.html#da...) but the output always comes out the same way. I've tried the following code with Visual Studio Express 2008 and g++ 4.2 on Solaris 10. I'm using Boost 1.39.0. Any help appreciated. matthew #include <fstream> #include <functional> #include <iostream> #include <sstream> #include "boost/date_time/gregorian/gregorian.hpp" #include "boost/date_time/posix_time/posix_time.hpp" #include "boost/date_time/local_time/local_time.hpp" using namespace std; int main(int argc, char** argv) { stringstream ss; ifstream in( argv[1] ); string inputFormat = argv[2]; string outputFormat = argv[3]; //I want my own formatting. boost::local_time::local_time_facet* output_facet = new boost::local_time::local_time_facet(); boost::local_time::local_time_input_facet* input_facet = new boost::local_time::local_time_input_facet(); ss.imbue(locale(locale::classic(), output_facet)); ss.imbue(locale(ss.getloc(), input_facet)); output_facet->format( outputFormat.c_str() ); input_facet->format( inputFormat.c_str() ); while ( !in.eof() ) { string s; getline( in, s ); ss<<s; boost::posix_time::ptime p; ss>>p; //This works fine. string s1 = boost::posix_time::to_simple_string(p); cout<<s1<<"\n"; ss.str(""); ss<<p; //I don't get my format. string s2 = ss.str(); cout<<s2<<"\n"; std::ws(in); ss.str(""); } } ----Input File---- 05:01:2007_23:08:02 06:01:2007_23:09:04 07:01:2007_16:32:58 07:01:2007_18:51:42 07:01:2007_19:51:27 ----Output---- 2007-Jan-05 23:08:02 2007-Jan-05 23:08:02 2007-Jan-06 23:09:04 2007-Jan-06 23:09:04 2007-Jan-07 16:32:58 2007-Jan-07 16:32:58 2007-Jan-07 18:51:42 2007-Jan-07 18:51:42 2007-Jan-07 19:51:27 2007-Jan-07 19:51:27