PHP实现显示网站运行时间

PHP代码：

<?php
// 设置时区
date_default_timezone_set('Asia/Shanghai');
/**
* 秒转时间，格式 年 月 日 时 分 秒
* @param int $time
* @return array|boolean
*/
function Sec2Time($time){
    if(is_numeric($time)){
        $value = array(
        "years" => 0, "days" => 0, "hours" => 0,
        "minutes" => 0, "seconds" => 0,);
        if($time >= 31556926){
            $value["years"] = floor($time/31556926);
            $time = ($time%31556926);
        }
        if($time >= 86400){
            $value["days"] = floor($time/86400);
            $time = ($time%86400);
        }
        if($time >= 3600){
            $value["hours"] = floor($time/3600);
            $time = ($time%3600);
        }
        if($time >= 60){
            $value["minutes"] = floor($time/60);
            $time = ($time%60);
        }
        $value["seconds"] = floor($time);
        return (array) $value;
    }else{
        return (bool) FALSE;
    }
}

// 本站创建的时间
$site_create_time = strtotime('2015-07-01 00:00:00');
$time = time() - $site_create_time;
$uptime = Sec2Time($time);
?>

HTML代码：

本站已运行：
<span style="color:red;">
    <?php echo $uptime['years']; ?>年
    <?php echo $uptime['days']; ?>天
    <?php echo $uptime['hours']; ?>小时
    <?php echo $uptime['minutes']; ?>分
    <?php echo $uptime['seconds']; ?>秒
</span>