<div class="form-group ">
<label for="">ラベル</label>
<div class="input-group">
<input type="text" class="form-control pull-right js-datepicker" value="" placeholder="開始日">
<span class="input-group-addon">〜</span>
<input type="text" class="form-control pull-right js-datepicker" value="" placeholder="終了日">
</div><!-- .input-group -->
</div>