Sorry, I think I sent an empty message just before this one. Please ignore it. There are several test failures for date_time and other Boost libs on sunos5+gcc (see for example http://tinyurl.com/4y6tx) that are due to incomplete wide character support on that platorm. This situation appears to be similar to a number other configurations (e.g. win32+mingw) which have a similar or identical tests marked as expected failures in the test matrix. I think sunos5+gcc should be treated similarly. Here is the relevant section of boost/config/stdlib/libstdcpp3.hpp: #if !defined(_GLIBCPP_USE_WCHAR_T) && !defined(_GLIBCXX_USE_WCHAR_T) # define BOOST_NO_CWCHAR # define BOOST_NO_CWCTYPE # define BOOST_NO_STD_WSTRING # define BOOST_NO_STD_WSTREAMBUF #endif -- Caleb Epstein caleb dot epstein at gmail dot com