Javascript倒数与数据库输入

Question

sset($_POST["confirm"])) {
 $check="select * from tbl_donate where receiverId='$username' and status = 'created'";
    $exc=mysqli_query($conn,$check);
    $match=mysqli_fetch_array($exc);

    $cElapseTime=$match['cElapseTime'];
    $timeCreated=$match['timeCreated'];
    $receiverId=$match['receiverId'];
    $senderId=$match['senderId'];
    $pop = $match['proof'];
    $projectId = $match['projectId'];
    $actlAmt = $match['amtRec'];
    //$errMsg = $projectId;
    $now=date("Y-m-d h:i:s");
    $t1 = strtotime($timeCreated);
    $t2 = strtotime($cElapseTime);
    $t3 = strtotime($now);
   $diff = $t2 - $t3;
   $hours = gmdate("H:i:s", $diff);

i want to pass this as a count down to a javascript, and also after the countdown is zero, it should automatically stops the countdown and reload the page and update a column in the database.

i need help on this