js acquisition date or dates after 7 days 7 days before

js acquisition date or dates after 7 days 7 days before (the removal of the Internet, record their own use)

function fun_date(num) { 
    var date1 = new Date();
    //今天时间
    var time1 = date1.getFullYear() + "-" + (date1.getMonth() + 1) + "-" + date1.getDate()
    console.log(time1);
    var date2 = new Date(date1);
     date2.setDate(date1.getDate() + num);
     //num是正数表示之后的时间，num负数表示之前的时间，0表示今天
     var time2 = date2.getFullYear() + "-" + (date2.getMonth() + 1) + "-" + date2.getDate(); 
    console.log(time2);
    return time2;
    }
    fun_date(7);
    //2019-6-28
    //2019-7-5

js Gets the specified date of the week

function fun_week(datestr){
    var weekArray = new Array("周日", "周一", "周二", "周三", "周四", "周五", "周六");
    var week = weekArray[new Date(datestr).getDay()];
    console.log(week);
    return week;
}
 fun_week('2019-6-28') //周五