>y</span><span class="p">,</span> <span class="n">TimeDelta</span><span class="p">):</span>
            <span class="c1"># positive delta </span>
            <span class="k">if</span> <span class="n">y</span><span class="o">.</span><span class="n">jd</span> <span class="o">&gt;=</span> <span class="mi">0</span><span class="p">:</span>
                <span class="bp">self</span><span class="o">.</span><span class="n">_start_time</span> <span class="o">=</span> <span class="n">x</span>
                <span 