XML File – test.xml
===============
<?xml version=”1.0″ encoding=”UTF-8″?>
<PHPCodez>
<Update>
<Time>26</Time>
</Update>
</PHPCodez>

PHPCode

========

<?php
$xmlFIle    =       “test.xml”;
$xmlString       =  file_get_contents($xmlFIle);
$content=simplexml_load_string($xmlString);
echo $content->Update->Time;
$content->Update->Time = date(“Y-M-d h:i:s”);
$content->asXML($xmlFIle);
?>