Hello, date_time on Windows needs windows.h in order to have the definitions for FILETIME and GetSystemTimeAsFileTime and friends and does not use the same technique as other boost headers : if BOOST_USE_WINDOWS_H is defined include <windows.h> otherwise forward define functions as needed. In date_time is more difficult because it is a header_only library. Please find attached a patch to solve this issue and the test report of the library on the compiler I have at my disposal. I have taken precautions in order to ensure it will work on x64 Windows (please see comments related to the conversion between FILETIME and __int64) and I see no reason it should have changed for other platforms, but only testing will tell. Thank you, -- Emil Mieilica __________ Information from ESET NOD32 Antivirus, version of virus signature database 3506 (20081009) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com