您需要使用getDate()来获取日期部分。getDay()函数返回日期(Sunday = 0, Monday = 1…)，getMonth()返回一个基于0的索引，因此需要将其增加1。

 var currentdate = new Date(); 

 var datetime = "Last Sync: " + currentdate.getDate() + "/"+  (parseInt(currentdate.getMonth())    + 1)
   + "/" + currentdate.getFullYear() + " @ "  
   + currentdate.getHours() + ":"  
   + currentdate.getMinutes() + ":" + currentdate.getSeconds(); 

function UniqueDateTime(format='',language='en-US'){
    //returns a meaningful unique number based on current time, and milliseconds, making it virtually unique
    //e.g : 20170428-115833-547
    //allows personal formatting like more usual :YYYYMMDDHHmmSS, or YYYYMMDD_HH:mm:SS
    var dt = new Date();
    var modele="YYYYMMDD-HHmmSS-mss";
    if (format!==''){
      modele=format;
    }
    modele=modele.replace("YYYY",dt.getFullYear());
    modele=modele.replace("MM",(dt.getMonth()+1).toLocaleString(language, {minimumIntegerDigits: 2, useGrouping:false}));
    modele=modele.replace("DD",dt.getDate().toLocaleString(language, {minimumIntegerDigits: 2, useGrouping:false}));
    modele=modele.replace("HH",dt.getHours().toLocaleString(language, {minimumIntegerDigits: 2, useGrouping:false}));
    modele=modele.replace("mm",dt.getMinutes().toLocaleString(language, {minimumIntegerDigits: 2, useGrouping:false}));
    modele=modele.replace("SS",dt.getSeconds().toLocaleString(language, {minimumIntegerDigits: 2, useGrouping:false}));
    modele=modele.replace("mss",dt.getMilliseconds().toLocaleString(language, {minimumIntegerDigits: 3, useGrouping:false}));
    return modele;
}

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>

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

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

var currentdate = new Date();

    var datetime = "Last Sync: " + currentdate.getDate() + "/"+(currentdate.getMonth()+1) 
    + "/" + currentdate.getFullYear() + " @ " 
    + currentdate.getHours() + ":" 
    + currentdate.getMinutes() + ":" + currentdate.getSeconds();

将. getday()方法更改为. getdate()，并将1添加到month，因为它从0开始计算月份。