时间

//当天
function writeCurrentDate() {
    var now = new Date();
    var year = now.getFullYear(); //得到年份
    var month = now.getMonth();//得到月份
    var date = now.getDate();//得到日期
    var day = now.getDay();//得到周几
    var hour = now.getHours();//得到小时
    var minu = now.getMinutes();//得到分钟
    var sec = now.getSeconds();//得到秒
    var MS = now.getMilliseconds();//获取毫秒
    var week;
    month = month + 1;
    if (month < 10) month = "0" + month;
    if (date < 10) date = "0" + date;
    if (hour < 10) hour = "0" + hour;
    if (minu < 10) minu = "0" + minu;
    if (sec < 10) sec = "0" + sec;
    if(MS < 100){
        MS = "0" + MS
    };
    var arr_week = new Array("星期日", "星期一", "星期二", "星期三", "星期四", "星期五", "星期六");
    week = arr_week[day];
    var time = "";
    //time = year + "-" + month + "-" + date  + " " + hour + ":" + minu + ":" + sec;
    time = year + "-" + month + "-" + date  + " " + '23' + ":" + '59' + ":" + '59';
    //当前日期赋值给当前日期输入框中（jQuery easyUI）

    $("#PicUp_endTime").val(time);
    //设置得到当前日期的函数的执行间隔时间，每1000毫秒刷新一次。
    // var timer = setTimeout("writeCurrentDate()", 1000);
}
//三天前
function threeday(){
    var date = new Date();
    date.setDate(date.getDate() - 3);//获取3天前的日期
    var year = date.getFullYear();
    var month = date.getMonth() + 1;
    if( month <10){
        month = '0' + month;
    }
    var day = date.getDate();
    if( day < 10){
        day = '0' + day;
    }
    var time = year + "-" + month + "-" + day  + " " + '00' + ":" + '00' + ":" + '00';
    $("#PicUp_startTime").val(time);
}

var nowdays = new Date();
var year = nowdays.getFullYear();
var month = nowdays.getMonth();
if(month==0){
    month = 12;
    year = year-1;
 
}
if(month<10){
    month = '0'+month;
}
            
var myDate = new Date(year,month,0);
 
var startDate = year+'-'+month; //上个月第一天
var endDate = year+'-'+month+'-'+myDate.getDate()+' 23:59:00';//上个月最后一天
console.log(endDate)