我想我现在很晚分享我的答案，但是我认为这是值得的。

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

D = new Date(Date(00));
M = D.getMonth()+1;
H = D.getHours();
Mi = D.getMinutes();

N = "AM"
if (H >= 12)
N = "PM"
if (H > 12)
{
H = H-12
}

amtOfZeroes = 2;
isNeg = false;

if (M < 0)
{
M = Math.abs(M);
isNeg = true;
}
Mo = Math.round(M) + "";
while(Mo.length < amtOfZeroes)
{

Mo = "0" + Mo; 
}
if (isNeg)
Mo = "-" + Mo;

if (H < 0)
{
H = Math.abs(H);
isNeg = true;
}
Ho = Math.round(H) + "";
while(Ho.length < amtOfZeroes)
{
Ho = "0" + Ho; 
}
if (isNeg)
Ho = "-" + Ho;

if (Mi < 0)
{
Mi = Math.abs(Mi);
isNeg = true;
}
Min = Math.round(Mi) + "";
while(Min.length < amtOfZeroes)
{
Min = "0" + Min; 
}
if (isNeg)
Min = "-" + Min;

T = Ho + ":" + (Min)

Mo + "/" + D.getDate() + "/" + D.getFullYear() + "  " + T + " " + N

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

function display_c(){   
    var refresh = 1000; // Refresh rate in milli seconds    
    mytime = setTimeout('display_ct()', refresh)    
}

function display_ct() {

    var strcount    
    var currentdate = new Date();

    document.getElementById('ct').innerHTML = currentdate.toDateString() + " " + currentdate.getHours() + ":" + currentdate.getMinutes() + ":" + currentdate.getSeconds();

    tt = display_c();   
}


id = 'ct'     // Replace in Your id

onload = "display_ct();"     // Type inside a Body Tag

clock.now   --> 1462248501241
clock.time  --> 11:08 PM
clock.weekday   --> monday
clock.day   --> 2
clock.month --> may
clock.year  --> 2016
clock.since(1462245888784)  --> 44 minutes
clock.until(1462255888784)  --> 2 hours
clock.what.time(1462245888784)  --> 10:24 PM
clock.what.weekday(1461968554458)   --> friday
clock.what.day('14622458887 84')    --> 2
clock.what.month(1461968554458) --> april
clock.what.year('1461968554458')    --> 2016
clock.what.time()   --> 11:11 PM
clock.what.weekday('14619685abcd')  -->     clock.js error : expected unix timestamp as argument
clock.unit.seconds  --> 1000
clock.unit.minutes  --> 60000
clock.unit.hours    --> 3600000
clock.unit.days --> 86400000
clock.unit.weeks    --> 604800000
clock.unit.months   --> 2628002880
clock.unit.years    --> 31536000000

var datetime = new Date().toLocaleString().slice(0,9) +" "+new Date(new Date()).toString().split(' ')[4];
console.log(datetime);

 $(document).ready(function () { 
            var fpsOut = document.getElementById('myTime');
            setInterval(function () {
                var d = new Date(); 
                fpsOut.innerHTML = d;
            }, 1000);
        });

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="myTime"></div>

console.log(formatAMPM());
function formatAMPM() {
  var date = new Date();
  var hours = date.getHours();
  var minutes = date.getMinutes();
  var seconds = date.getSeconds();
  var ampm = hours >= 12 ? 'PM' : 'AM';
  hours = hours % 12;
  hours = hours ? hours : 12; // the hour '0' should be '12'
  minutes = minutes < 10 ? '0'+minutes : minutes;
  return strTime = date.getMonth() + '/' + date.getDay()+'/'+date.getFullYear()+' '+ hours + ':' + minutes +':'+ seconds + " " +ampm;
}

<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>

<p id="DateTimeBox">Click The Button To Show Date And Time</p>
<button onclick="ShowDate();"> Show Date </button>
<script>
  function ShowDate() {
    document.getElementById('DateTimeBox').innerHTML = Date();
  }
</script>