获取当前时间（年月日、时分秒、星期）

<p id="demo"></p>

function getDate() {
    var now = new Date();
    // 年月日
    var year = now.getFullYear();
    var month = now.getMonth() + 1;
    month = month < 10 ? "0" + month : month; //变个位数时补个0
    var date = now.getDate();
    date = date < 10 ? "0" + date : date;

    // 时分秒
    var hour = now.getHours();
    hour = hour < 10 ? "0" + hour : hour;
    var minutes = now.getMinutes();
    minutes = minutes < 10 ? "0" + minutes : minutes;
    var sec = now.getSeconds();
    sec = sec < 10 ? "0" + sec : sec;

    // 星期
    var arr_day = ['星期日', '星期一', '星期二', '星期三', '星期四', '星期五', '星期六', ]
    var day = now.getDay(); //返回0~6

    return year + "年" + month + "月" + date + "日" + hour + ":" + minutes + ":" + sec + arr_day[day];
}

document.getElementById("demo").innerHTML = getDate();