float center for below two lines
<label for date from><input datepicker> <label for date to><input datepicker>//line 1
<button>//line 2

<div class="row">
    <div class="col-sm-12 col-md-6">
       <div class="float-right">
           <span>date from</span>
           <input>
       </div>
    </div>
    <div class="col-sm-12 col-md-6">
       <div class="float-left">
           <span>date to</span>
           <input>
       </div>
    </div>
</div>

label from
input
label to
input