Enabling boost::date_time::posix_time::nanosec().

Hi. Is there a quick way to determine whether one's operating system supports the nanosecond precision clock? Also; I realise that BOOST_DATE_TIME_HAS_NANOSECONDS needs to be defined to use nanosec() method. But; should I be able (if my operating system supports it) to define support for nanosecond time resolution at installation time? I.e. would it suffice to use a bjam commandline parameter defining nanosecond support when building the Boost date_time libraries? Also; how do I configure nanosecond support for subsequent compilation of programs which use Boost and require nanosecond posix_time resolution? Greetings, Andre. [Non-text portions of this message have been removed]