Js 日期加减天数详解编程语言

<SCRIPT language="javascript"> 
function addDate(dd,dadd){ 
var a = new Date(dd) 
a = a.valueOf() 
a = a + dadd * 24 * 60 * 60 * 1000 
a = new Date(a) 
return a; 
} 
 
//抓取现在日期 
 
var now = new Date("2008/03/01"); 
var years = now.getYear()+1; 
var months = now.getMonth()+1; 
var days = now.getDate(); 
var hours = now.getHours(); 
 
//抓取前一天日期 
 
NextNow = addDate(months+"/"+days+"/"+years,-1); 
years = NextNow.getYear(); 
months = NextNow.getMonth()+1; 
days = NextNow.getDate(); 
 
alert("加一年减一天的日期:"+years+"年"+months+"月"+days+"日"); 
 
</SCRIPT>