span class="keyword">public</span><span class="special">:</span>
  <span class="comment">// types</span>
  <span class="keyword">typedef</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">posix_time</span><span class="special">::</span><span class="identifier">time_duration</span>                      <a name="boost.local_time.custom_time_zone_base.time_duration_type"></a><span class="identifier">time_duration_type</span><span class="special">;</span>
  <span