计算日期差（用于计算年龄等）

//日期格式化
Date.prototype.Format = function (fmt) {  
        var o = {
            "M+": this.getMonth() + 1, //月份 
            "d+": this.getDate(), //日 
            "h+": this.getHours(), //小时 
            "m+": this.getMinutes(), //分 
            "s+": this.getSeconds(), //秒 
            "q+": Math.floor((this.getMonth() + 3) / 3), //季度 
            "S": this.getMilliseconds() //毫秒 
        };
        if (/(y+)/.test(fmt)) fmt = fmt.replace(RegExp.$1, (this.getFullYear() + "").substr(4 - RegExp.$1.length));
        for (var k in o)
        if (new RegExp("(" + k + ")").test(fmt)) fmt = fmt.replace(RegExp.$1, (RegExp.$1.length == 1) ? (o[k]) : (("00" + o[k]).substr(("" + o[k]).length)));
        return fmt;
    }


//
var myDate = new Date().Format("yyyy-MM-dd");

//计算时间差
function daysBetween(DateOne,DateTwo)  
{   
    var OneMonth = DateOne.substring(5,DateOne.lastIndexOf ('-'));  
    var OneDay = DateOne.substring(DateOne.length,DateOne.lastIndexOf ('-')+1);  
    var OneYear = DateOne.substring(0,DateOne.indexOf ('-'));  

    var TwoMonth = DateTwo.substring(5,DateTwo.lastIndexOf ('-'));  
    var TwoDay = DateTwo.substring(DateTwo.length,DateTwo.lastIndexOf ('-')+1);  
    var TwoYear = DateTwo.substring(0,DateTwo.indexOf ('-'));  
 //Date.parse();需要输入（月/日/年）
 /* 参考https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Date/parse*/
    var cha=((Date.parse(OneMonth+'/'+OneDay+'/'+OneYear)- Date.parse(TwoMonth+'/'+TwoDay+'/'+TwoYear))/86400000);   
    return Math.abs(cha);  
}