JavaScript计算日期的函数

注意：Date对象获得的月份是从0开始记的，这个让我耽误了不少时间：

 

function addDays(nd){    var day = new Date();    var newtimems = day.getTime() + (nd * 24 * 60 * 60 * 1000);    day.setTime(newtimems);    var xyear = day.getFullYear();    var xmonth = day.getMonth()+1 < 10? "0"+ (day.getMonth() + 1):""+(day.getMonth() + 1);    var xday = day.getDate() < 10? "0"+day.getDate():""+day.getDate();    return xyear + "-" + xmonth + "-" + xday;}