Displaying javascript running clock time for selected timezone

<?php
$timeFormat = $_SESSION["display"]["php_time_format"];

$currentTime_client = parse_date_for_clock($_SESSION["timezone"], $connA);
$currentTime_system = date("F d, Y ".$timeFormat);

if($timeFormat=="h:i:s A"){
    $clockFormat = "12";
}else{
    $clockFormat = "24";
}
?>
<script type="text/javascript">

var serverDate_client;
var serverDate_system;

function getServerDate_client(){
serverDate_client=new Date("<?php echo $currentTime_client;?>");
}
function getServerDate_system(){
serverDate_system=new Date("<?php echo $currentTime_system;?>");
}

function tick(timeFormat,showTimeFor,showTimeDiv){
if(showTimeFor=="client"){
    serverDate=serverDate_client;
}else{
    serverDate=serverDate_system;
}


serverDate.setSeconds(serverDate.getSeconds()+1);
var currentHours = serverDate.getHours();
var ampm="";
if(timeFormat=='12'){
if(currentHours >=12){
    ampm="PM";
}else{
    ampm="AM";
}
currentHours = (currentHours > 12 ) ? currentHours - 12 : currentHours;
currentHours = (currentHours == 0 ) ? 12 : currentHours;

}
if (currentHours<10) currentHours="0"+currentHours;

var min = serverDate.getMinutes();
if (min<10) min="0"+min;
var sec = serverDate.getSeconds();
if (sec<10) sec="0"+sec;
document.getElementById(showTimeDiv).innerHTML = currentHours + ":" + min + ":" + sec+" "+ampm;
}

window.onload=function(){
getServerDate_client();
setInterval("tick('<?php echo $clockFormat;?>','client','client_clock')", 1000);
getServerDate_system();
setInterval("tick('<?php echo $clockFormat;?>','system','system_clock')", 1000);
}
</script>



======== php time function definition used in above script==========
function parse_date($gmtoffset, $connA) {// parse date and time both

        $currdate = date("Y-m-d H:i:s");
        return mysql_fetch_object(mysql_query("SELECT DATE_FORMAT(CONVERT_TZ('$currdate', '".date("P")."', '$gmtoffset'), '".$_SESSION["display"]["mysql_date_format"]." ".$_SESSION["display"]["mysql_time_format"]."') AS display_date", $connA))->display_date;
    }

    function parse_date_only($gmtoffset, $connA) {

        $currdate = date("Y-m-d H:i:s");
        return mysql_fetch_object(mysql_query("SELECT DATE_FORMAT(CONVERT_TZ('$currdate', '".date("P")."', '$gmtoffset'), '".$_SESSION["display"]["mysql_date_format"]."') AS display_date", $connA))->display_date;
    }
    function parse_time_only($gmtoffset, $connA) {

        $currdate = date("Y-m-d H:i:s");
        return mysql_fetch_object(mysql_query("SELECT DATE_FORMAT(CONVERT_TZ('$currdate', '".date("P")."', '$gmtoffset'), '".$_SESSION["display"]["mysql_time_format"]."') AS display_date", $connA))->display_date;
    }

    function parse_date_for_clock($gmtoffset, $connA) {

        $currdate = date("Y-m-d H:i:s");
        $format = "%M %d %Y ".$_SESSION[display][mysql_time_format];
        return mysql_fetch_object(mysql_query("SELECT DATE_FORMAT(CONVERT_TZ('$currdate', '".date("P")."', '$gmtoffset'), '$format') AS display_date", $connA))->display_date;
    }