var bDate = new Date("2015-2-25"),
var nDate = new Date(),
var eDate = new Date(bb.getFullYear(),bb.getMonth(),bb.getDate());
var daycount = (bDate-eDate)/24/60/60/1000;
console.log(daycount);
原文：http://www.cnblogs.com/jiaojiaome/p/4463270.html