Issue on Loading Collapsed List (Need to be Expanded)

can you please tale a look at this demo and let me know how I can load the list in Expand mode either in CSS or jQuery? I tried to

 $('.tree li:has(ul)').addClass('parent_li').find(' > span').attr('title', 'Expand this branch');

before all of the code but still loading the list collapsed

      $(document).ready(function() {
  
$(function() {
  $('.tree li:has(ul)').addClass('parent_li').find(' > span').attr('title', 'Collapse this branch');
  $('.tree li.parent_li > span').on('click', function(e) {
    var children = $(this).parent('li.parent_li').find(' > ul > li');
    if (children.is(":visible")) {
      children.hide('fast');
      $(this).attr('title', 'Expand this branch').find(' > i').addClass('icon-plus-sign').removeClass('icon-minus-sign');
    } else {
      children.show('fast');
      $(this).attr('title', 'Collapse this branch').find(' > i').addClass('icon-minus-sign').removeClass('icon-plus-sign');
    }
    e.stopPropagation();
  });
});

});

.tree li {
  list-style-type: none;
  margin: 0;
  padding: 10px 5px 0 5px;
  position: relative
}

.tree li::before,
.tree li::after {
  content: '';
  left: -20px;
  position: absolute;
  right: auto;
  z-index: -1;  
}

.tree li::before {
  border-left: 1px solid #999;
  bottom: 25px;
  height: 100%;
  top: -5px;
  width: 2px;

}

.tree li::after {
  border-top: 1px solid #999;
  height: 20px;
  top: 25px;
  width: 25px
}

.tree li span {
  -moz-border-radius: 5px;
  -webkit-border-radius: 5px;

 

}

.tree li.parent_li>span {
  cursor: pointer
}

.tree>ul>li::before,
.tree>ul>li::after {
  border: 0
}

.tree li:last-child::before {
  height: 30px
}

.tree li.parent_li>span:hover,
.tree li.parent_li>span:hover+ul li span {
  background: #eee;
  border: 1px solid #94a0b4;
  color: #000
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="container">
<div class="tree">
  <ul>
    <li>
      <span><i class="fa fa-plus-circle" aria-hidden="true"></i> 2013, Week 2</span>
      <ul>
        <li>
          <span class="btn btn-default"><i class="icon-minus-sign"></i> Monday, January 7: 8.00 hours</span>
          <ul>
            <li>
             <span><i class="icon-time"></i> 8.00</span>
            </li>
          </ul>
        </li>
        <li>
          <span class="btn btn-default"><i class="icon-minus-sign"></i> Tuesday, January 8: 8.00 hours</span>
          <ul>
            <li>
              <span><i class="icon-time"></i> 6.00</span> 
            </li>
            <li>
              <span><i class="icon-time"></i> 2.00</span> 
            </li>
          </ul>
        </li>
        <li>
          <span class="btn btn-default"><i class="icon-minus-sign"></i> Wednesday, January 9: 6.00 hours</span>
          <ul>
            <li>
             <span><i class="icon-time"></i> 3.00</span>
            </li>
            <li>
              <span><i class="icon-time"></i> 3.00</span>
            </li>
          </ul>
        </li>
        <li>
          <span class="btn btn-default"><i class="icon-minus-sign"></i> Wednesday, January 9: 4.00 hours</span>
          <ul>
            <li>
             <span><i class="icon-time"></i> 2.00</span>
            </li>
          </ul>
        </li>
      </ul>
    </li>
  </ul>
</div>

</div>