- <?php  
-     //php的时间是以秒算。js的时间以毫秒算  
-     date_default_timezone_set(‘PRC‘);  
-     //date_default_timezone_set("Asia/Hong_Kong");//地区  
-    
-     $timestr = "2017-3-21 18:50:00";//倒计时时间  
-     $time = strtotime($timestr);//时间戳  
-     $nowtime = time();//当前时间戳  
-    
-     if ($time>=$nowtime){  
-         $overtime = $time-$nowtime; //实际剩下的时间(单位/秒)  
-     }else{  
-         $overtime=0;  
-     }  
- ?>  
- <!DOCTYPE html>  
- <html lang="en">  
- <head>  
-     <meta charset="UTF-8">  
-     <title>Document</title>  
-   
- </head>  
- <body>  
-   
- <script language="JavaScript">  
-     var runtimes = 0;  
-     function GetRTime(){  
-         var nMS = <?php echo $overtime; ?>*1000-runtimes*1000;  
-    
-         if (nMS>=0){  
-             var nD=Math.floor(nMS/(1000*60*60*24))%24;  
-             var nH=Math.floor(nMS/(1000*60*60))%24;  
-             var nM=Math.floor(nMS/(1000*60)) % 60;  
-             var nS=Math.floor(nMS/1000) % 60;  
-             document.getElementById("RemainD").innerHTML=nD;  
-             document.getElementById("RemainH").innerHTML=nH;  
-             document.getElementById("RemainM").innerHTML=nM;  
-             document.getElementById("RemainS").innerHTML=nS;  
-             runtimes++;  
-             if(nD==0){  
-                 //天数0 隐藏天数  
-                 document.getElementById("hideD").style.display="none";  
-                 if(nH==0){  
-                     //数0 隐藏天数  
-                     document.getElementById("hideH").style.display="none";  
-                     if(nM==0){  
-                         document.getElementById("hideM").style.display="none";  
-                         if(nS==0){  
-                             alert("倒计时完毕");  
-                         }  
-                     }  
-                 }  
-             }  
-             setTimeout("GetRTime()",1000);  
-         }  
-     }  
-     window.onload = function() {  
-         GetRTime();  
-     }  
- </script>  
- <h4>开售还有 <span id="hideD"><strong id="RemainD"></strong>天</span> <span id="hideH"><strong id="RemainH"></strong>小时</span><span id="hideM"> <strong id="RemainM"></strong>分钟</span> <span id="hideS"><strong id="RemainS"></strong>秒</span></h4>  
- </body>  
- </html>  
 
php倒计时代码编写详细步骤
原文:http://www.cnblogs.com/kewem98898/p/7667385.html