使用javascript倒计时与服务器端时间

Question

我有两个用PHP编写的脚本来获取时间服务器端,另一个是基于日期和时间的JavaScript倒计时.我不确定我做错了什么,但是当我将日期和时间传递给javascript时,它显示0days 0小时和1秒然后到期.无论将来我设定日期和时间有多远,这都会发生.如何将时间正确地传递到此JavaScript代码中？

<?php
$date = 'July 19 2011 05:00:00 PM PDT';
$exp_date = "var end = new Date('". $date ."');";
$todays_date = date("F j Y g:i:s A T");

if ($todays_date < $exp_date) {
?>
<script>
<?php echo $exp_date ;?>

var _second = 1000;
var _minute = _second * 60;
var _hour = _minute * 60;
var _day = _hour *24
var timer;

function showRemaining()
{
    var now = new Date();
    var distance = end - now;
    if (distance < 0 ) {
       clearInterval( timer );
       document.getElementById('countdown').innerHTML = 'EXPIRED!';

       return;
    }
    var days = Math.floor(distance / _day);
    var hours = Math.floor( (distance % _day ) / _hour );
    var minutes = Math.floor( (distance % _hour) / _minute );
    var seconds = Math.floor( (distance % _minute) / _second );

    document.getElementById('countdown').innerHTML = 'Days: ' + days + '<br />';
    document.getElementById('countdown').innerHTML += 'Hours: ' + hours+ '<br />';
    document.getElementById('countdown').innerHTML += 'Minutes: ' + minutes+ '<br />';
    document.getElementById('countdown').innerHTML += 'Seconds: ' + seconds+ '<br />';
}

timer = setInterval(showRemaining, 1000);
</script>
<?php
} else {
    echo "Times Up";
}
?>
<div id="countdown"></div>

Answer 1

您应该向客户端提供当前时间和结束时间,因为它们使用自己的系统时间来反对服务器的时间.

以下是此问题的完整解决方案.

<?php
$date = 'July 20 2011 05:00:00 PM PDT';
$exp_date = strtotime($date);
$now = time();

if ($now < $exp_date) {
?>
<script>
// Count down milliseconds = server_end - server_now = client_end - client_now
var server_end = <?php echo $exp_date; ?> * 1000;
var server_now = <?php echo time(); ?> * 1000;
var client_now = new Date().getTime();
var end = server_end - server_now + client_now; // this is the real end time

var _second = 1000;
var _minute = _second * 60;
var _hour = _minute * 60;
var _day = _hour *24
var timer;

function showRemaining()
{
    var now = new Date();
    var distance = end - now;
    if (distance < 0 ) {
       clearInterval( timer );
       document.getElementById('countdown').innerHTML = 'EXPIRED!';

       return;
    }
    var days = Math.floor(distance / _day);
    var hours = Math.floor( (distance % _day ) / _hour );
    var minutes = Math.floor( (distance % _hour) / _minute );
    var seconds = Math.floor( (distance % _minute) / _second );

    var countdown = document.getElementById('countdown');
    countdown.innerHTML = '';
    if (days) {
        countdown.innerHTML += 'Days: ' + days + '<br />';
    }
    countdown.innerHTML += 'Hours: ' + hours+ '<br />';
    countdown.innerHTML += 'Minutes: ' + minutes+ '<br />';
    countdown.innerHTML += 'Seconds: ' + seconds+ '<br />';
}

timer = setInterval(showRemaining, 1000);
</script>
<?php
} else {
    echo "Times Up";
}
?>
<div id="countdown"></div>