我想现在分享我的答案已经很晚了，但我认为这是值得的。

function __getCurrentDateTime(format){
    var dt=new Date(),x,date=[];
    date['d']=dt.getDate();
    date['dd']=dt.getDate()>10?dt.getDate():'0'+dt.getDate();
    date['m']=dt.getMonth()+1;
    date['mm']=(dt.getMonth()+1)>10?(dt.getMonth()+1):'0'+(dt.getMonth()+1);
    date['yyyy']=dt.getFullYear();
    date['yy']=dt.getFullYear().toString().slice(-2);
    date['h']=(dt.getHours()>12?dt.getHours()-12:dt.getHours());
    date['hh']=dt.getHours();
    date['mi']=dt.getMinutes();
    date['mimi']=dt.getMinutes()<10?('0'+dt.getMinutes()):dt.getMinutes();
    date['s']=dt.getSeconds();
    date['ss']=dt.getSeconds()<10?('0'+dt.getSeconds()):dt.getSeconds();
    date['sss']=dt.getMilliseconds();
    date['ampm']=(dt.getHours()>=12?'PM':'AM');
    x=format.toLowerCase();
    x=x.indexOf('dd')!=-1?x.replace(/(dd)/i,date['dd']):x.replace(/(d)/i,date['d']);
    x=x.indexOf('mm')!=-1?x.replace(/(mm)/i,date['mm']):x.replace(/(m)/i,date['m']);
    x=x.indexOf('yyyy')!=-1?x.replace(/(yyyy)/i,date['yyyy']):x.replace(/(yy)/i,date['yy']);
    x=x.indexOf('hh')!=-1?x.replace(/(hh)/i,date['hh']):x.replace(/(h)/i,date['h']);
    x=x.indexOf('mimi')!=-1?x.replace(/(mimi)/i,date['mimi']):x.replace(/(mi)/i,date['mi']);
    if(x.indexOf('sss')!=-1){   x=x.replace(/(sss)/i,date['sss']);  }
    x=x.indexOf('ss')!=-1?x.replace(/(ss)/i,date['ss']):x.replace(/(s)/i,date['s']);
    if(x.indexOf('ampm')!=-1){  x=x.replace(/(ampm)/i,date['ampm']);    }
    return x;
}

console.log(__getCurrentDateTime());  //returns in dd-mm-yyyy HH:MM:SS
console.log(__getCurrentDateTime('dd-mm-yyyy'));    //return in 05-12-2016
console.log(__getCurrentDateTime('dd/mm*yyyy'));    //return in 05/12*2016
console.log(__getCurrentDateTime('hh:mimi:ss'));    //return in 13:05:30

console.log (__getCurrentDateTime (' h mi: ss ampm '));//下午1:5:30返回

getDay()获取星期几。3号是星期三。你需要getDate()，它会返回18。

同样，getMonth()从0开始，你需要加1来得到4(四月)。

演示:http://jsfiddle.net/4zVxp/

dt= new Date();
alert(dt.toISOString().substring(8,10) + "/" + 
dt.toISOString().substring(5,7)+ "/" + 
dt.toISOString().substring(0,4) + " " + 
dt.toTimeString().substring(0,8))

对于真正的mysql样式输出使用下面的函数:2019/02/28 15:33:12

如果你点击下面的“运行代码片段”按钮 它将向您展示一个简单的实时数字时钟示例 演示程序将出现在代码片段的下面。

function getDateTime() { var now = new Date(); var year = now.getFullYear(); var month = now.getMonth()+1; var day = now.getDate(); var hour = now.getHours(); var minute = now.getMinutes(); var second = now.getSeconds(); if(month.toString().length == 1) { month = '0'+month; } if(day.toString().length == 1) { day = '0'+day; } if(hour.toString().length == 1) { hour = '0'+hour; } if(minute.toString().length == 1) { minute = '0'+minute; } if(second.toString().length == 1) { second = '0'+second; } var dateTime = year+'/'+month+'/'+day+' '+hour+':'+minute+':'+second; return dateTime; } // example usage: realtime clock setInterval(function(){ currentTime = getDateTime(); document.getElementById("digital-clock").innerHTML = currentTime; }, 1000); <div id="digital-clock"></div>

看看这个也许会对你有用

<script language="JavaScript">
var dayarray=new Array("Sunday","Monday",
 "Tuesday","Wednesday","Thursday","Friday","Saturday")

var montharray=new Array("January","February","March",
 "April","May","June","July","August","September",
 "October","November","December")

function getthedate(){
var mydate=new Date()
var year=mydate.getYear()
if (year < 1000)
year+=1900
var day=mydate.getDay()
var month=mydate.getMonth()
var daym=mydate.getDate()
if (daym<10)
daym="0"+daym
var hours=mydate.getHours()
var minutes=mydate.getMinutes()
var seconds=mydate.getSeconds()
var dn="AM"
if (hours>=12)
dn="PM"
if (hours>12){
hours=hours-12
}
if (hours==0)
hours=12
if (minutes<=9)
minutes="0"+minutes
if (seconds<=9)
seconds="0"+seconds
//change font size here
var cdate="<small><font color='000000' face='Arial'><b>"+dayarray[day]+", 
    "+montharray[month]+" "+daym+", "+year+" "+hours+":"
 +minutes+":"+seconds+" "+dn
    +"</b></font></small>"
if (document.all)
document.all.clock.innerHTML=cdate
else if (document.getElementById)
document.getElementById("clock").innerHTML=cdate
else
document.write(cdate)
}
 if (!document.all&&!document.getElementById)
  getthedate()
  function goforit(){
  if (document.all||document.getElementById)
 setInterval("getthedate()",1000)
}

 </script>

enter code here

 <span id="clock"></span>

这应该可以达到目的:

function dateToString(date) {
    var month = date.getMonth() + 1;
    var day = date.getDate();
    var dateOfString = (("" + day).length < 2 ? "0" : "") + day + "/";
    dateOfString += (("" + month).length < 2 ? "0" : "") + month + "/";
    dateOfString += date.getFullYear();
    return dateOfString;
}

var currentdate = new Date();
var datetime = "Last Sync: ";
datetime += dateToString(currentdate );
datetime += + currentdate.getHours() + ":"
            + currentdate.getMinutes() + ":"
            + currentdate.getSeconds();