Click the calendar image on the right side.
<div class="easyui-panel" style="width:100%;max-width:400px;padding:30px 60px;">
<div style="margin-bottom:20px">
<input class="easyui-datebox" data-options="label:'Select Date:',labelPosition:'top',onSelect:onSelect" style="width:100%;">
</div>
<div style="margin:10px 0">
<span>Selected Date: </span>
<span id="result"></span>
</div>
</div>
<script>
function onSelect(date){
$('#result').text(date)
}
</script>