Hello World, I'm doing some experiments to use boost (1.33.1) under Win XP and with MinGW (5.1.3) environment. Boost was compiled with bjam with no particular options. I'm facing some problems on linking with boost_date_time. Here is the simple test program: #include <iostream> #include <string> #include <boost/date_time/posix_time/posix_time.hpp> using namespace std; using namespace boost::posix_time; int main (int argc, char** argv) { char dummy; ptime d1(min_date_time); ptime d2(max_date_time); cout << "min:" << to_simple_string(d1) << endl; cout << "max:" << to_simple_string(d2) << endl; cin.get(dummy); return 0; } Compiling lines are : g++ -DUSE_DATE_TIME_PRE_1_33_FACET_IO -I"E:\dev\boost_1_33_1" -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"main.d" -MT"main.d" -o"main.o" "../main.cpp" g++ -L"E:\dev\boost_1_33_1\stage\lib" -o"TestBOOST.exe" ./main.o -lboost_date_time-mgw-mt-d-1_33_1 I get the error (simplified output) : E:/dev/boost_1_33_1/boost/date_time/gregorian/greg_weekday.hpp: undefined reference to `boost::gregorian::greg_month::as_long_string() const' If I remove the lines with *to_simple_string*, I get no error. From the docs [*] it seems there may be a problem for streams support for some compilers, so I tryed to define USE_DATE_TIME_PRE_1_33_FACET_IO in my project, but with no effect. Does it needs to be done when compiling boost ? Is there any other way to solve my link problem ? (appart not using string output for dates :-) ) Thanks for any help. Franck,e- [*] http://www.boost.org/doc/html/date_time/details.html#date_time.buildinfo