pes</span>
  <span class="keyword">typedef</span> <span class="identifier">date_type</span><span class="special">::</span><span class="identifier">duration_type</span> <a name="boost.date_time.date_itr_base.duration_type"></a><span class="identifier">duration_type</span><span class="special">;</span>    
  <span class="keyword">typedef</span> <span class="identifier">date_type</span>                <a name="boost.date_time.date_itr_base.value_type"></a><span class="identifier">value_type</span><span class="