How to make it a function to apply it to a PHP variable?

<script>
    jQuery(function($){
        $('#timer').countdown({
            until: new Date("2015-11-04 12:00:00"),
            compact: true
        });
    });
</script>

I need to transform the code above into a function and then apply this function to a PHP variable that is inside a loop. How to do this?

while ( $linha = mysql_fetch_array($query) ) {

     echo $datafinal;           // Y-m-d h:i:s

}