If i use this then its working.
<td ><div> Timestamp: </div><input type="text" value="" class="datepicker"/></td>
$( ".datepicker" ).datepicker();
This above code is working but this is not working
<td class="datepicker" ><div> Timestamp: </div><input type="text" value=""/></td>
$( ".datepicker input" ).datepicker();
Those are both correct. Do you have some malformed HTML elsewhere on the page? Is a JavaScript error being thrown before .datepicker() is called?