用js获取格式化的当前时间以及n天前的日期时间

//获取当前格式化日期

//获取当前日期
    let date = new Date();
    let year = date.getFullYear();
    let month = date.getMonth()+1;
    let day = date.getDate();
    let hour = date.getHours();
    let minute = date.getMinutes();
    let second = date.getSeconds();
    let nowDate = year + "-" + (month < 10 ? "0" + month : month) + "-" + (day < 10 ? "0" + day : day)+" "+
    (hour < 10 ? "0" + hour : hour)+":"+(minute < 10 ? "0" + minute : minute)+":"+(second < 10 ? "0" + second : second);

//获取N天前日期(此处以30天为例)

//获取30天前得日期
    let lastDate = new Date(date - 1000 * 60 * 60 * 24 * 30);//最后30可以更改为任意天数N，意义：获取N天前的时间
    let lastYear = lastDate.getFullYear();
    let lastMonth = lastDate.getMonth()+1;
    let lastDay = lastDate.getDate();
    let lastHour = lastDate.getHours();
    let lastMinute = lastDate.getMinutes();
    let lastSecond = lastDate.getSeconds();
    let LDate = lastYear + "-" + (lastMonth < 10 ? "0" + lastMonth : lastMonth) + "-"+(lastDay < 10 ? "0" + lastDay : lastDay)+" "+
    (lastHour < 10 ? "0" + lastHour : lastHour)+":"+(lastMinute < 10 ? "0" + lastMinute : lastMinute)+":"+(lastSecond < 10 ? "0" + lastSecond : lastSecond);