显示多个计时器PHP + Javascript

I'm working on having multiple timers run in Javascript with the user data and time remaining pulled from a PHP + MySQL instance

Currently I have the following PHP Code:

<?php
$now = strtotime("now");
$allArrested = $conn->query("SELECT `user_id` FROM `user_jail` WHERE `jail_stop` > '$now'") or die(mysqli_error($conn));
if($allArrested->num_rows > 0){
    while($arrested = $allArrested->fetch_assoc()){
        foreach($arrested as $jailTime){
            $checkTime = $conn->query("SELECT `jail_stop` FROM `user_jail` WHERE `user_id` = '$jailTime'") or die(mysqli_error($conn));
            while($letsTime = $checkTime->fetch_assoc()){
                $x = $letsTime['jail_stop'];
                $letGo = $x - $now;                     
                foreach($arrested as $convict){
                    echo "<div>".usernameById($convict)." for <span class=\"time\">".$letGo."</span></div>";
                }
            }
        }
    }
}
?>

And the following javascript:

<script>
function startTimer(duration, display) {
    var timer = duration, minutes, seconds;
    setInterval(function () {
        minutes = parseInt(timer / 60, 10)
        seconds = parseInt(timer % 60, 10);
        minutes = minutes < 10 ? "0" + minutes : minutes;
        seconds = seconds < 10 ? "0" + seconds : seconds;
        display.textContent = minutes + ":" + seconds;
        if (--timer < 0) {
            timer = 0;
            display.textContent = "";
        }
    }, 1000);
}

window.onload = function () {
    var fiveMinutes = <?php echo $letGo; ?>,
    display = document.querySelector('.time');
    startTimer(fiveMinutes, display);
};
</script>

For testing purposes I have 4 different usernames. Currently only the first one is counting down.

The other 3 users counters remain on 90sec (variable $letGo). Is anyone able to help me with this?