absolute_time() in the TAO's version of OMG's Time Service is unimplemented

The following lines are from ACE_wrappers/TAO/orbsvcs/orbsvcs/Time/TAO_UTO.cpp

// Absolute time = Relative time + Base time.  ?? Find out more about
// the Base Time, UTC and Distributed Time Sync. Algos. [3].

CosTime::UTO_ptr
TAO_UTO::absolute_time (CORBA::Environment &)
    ACE_THROW_SPEC ((CORBA::SystemException))
{
  return 0;
}