原生js获取格式化的时间函数！

function formatDateTime() {
    var date = new Date(); //日期对象
    var now = "";
    now = date.getFullYear() + "-"; //读英文就行了
    now = now + (date.getMonth() + 1) + "-"; //取月的时候取的是当前月-1如果想取当前月+1就可以了
    now = now + date.getDate() + " ";
    now = now + date.getHours() + ":";
    now = now + date.getMinutes() + ":";
    now = now + date.getSeconds() + "";
    return now ;
    // document.getElementById("nowDiv").innerHTML = now; //div的html是now这个字符串
    // setTimeout("show()", 1000); //设置过1000毫秒就是1秒，调用show方法
}

优化，对于小时和分中不足10的情况，前面补 0：

function zh_now2(){
    var date = new Date();
    var year = date.getFullYear();
    var month = date.getMonth();
    var day = date.getDate();
    var hour = date.getHours()<10?"0"+date.getHours():date.getHours();
    var min = date.getMinutes()<10?"0"+date.getMinutes():date.getMinutes();
    var sec = date.getSeconds()<10?"0"+date.getSeconds():date.getSeconds();

    var timeStr = year +"年"+
                  month+"月"+
                  day+"日"+
                  hour+"时"+
                  min+"分"+
                  sec+"秒";
    return timeStr ;
}