Javascript倒計時不起作用

Question

每當我重新載入此頁面http://prince27.bplaced.net/Prince27-Website/html/slider_true.html時，倒計時重新開始。我做錯了什麼？

我已將endDate設置爲2012年9月20日，並計算了從現在起& endDate之間的毫秒數。

var today = new Date(); 

var endDate = new Date("20/09/2012"); //set the date you want timer to end 
var diffMs = (280800000); // milliseconds between now & endDate 
var diffDays = Math.round(diffMs/86400000); // days 
var diffHrs = Math.round((diffMs % 86400000)/3600000); // hours 
var diffMins = Math.round(((diffMs % 86400000) % 3600000)/60000); // minutes 
var diffSecs = Math.floor((((diffMs % 86400000) % 3600000) % 60000)/1000); 

完整劇本file

Answer 1

你硬編碼的區別：

var diffMs = (280800000); // milliseconds between now & endDate 

Answer 2

評論你的代碼，你已經爲diffMs硬編碼值，你永遠不使用today

var today = new Date(); 

var endDate = new Date("20/09/2012"); //set the date you want timer to end 
var diffMs = (280800000); // milliseconds between now & endDate