这是英国时区的例子。为特定时区设置偏移量。 例如:印度:+05:30，英国:+1

 function realUKTime() {
        // create Date object for current location
        var d = new Date();
        offset ='+1';
       
        // convert to msec
        // subtract local time zone offset
        // get UTC time in msec
        var utc = d.getTime() + (d.getTimezoneOffset() * 60000);

        // create new Date object for different city
        // using supplied offset
        var nd = new Date(utc + (3600000*offset));

        // return time as a string
        var s = nd.getSeconds();
        var i = nd.getMinutes();
        var h = nd.getHours();
        var cDate =  nd.getDate();
        var m =  nd.getUTCMonth();
        var y = nd.getFullYear();

       var newUkTime = nd.toDateString() + " "+ (Number(h)-1)+":"+i+':'+s
        $("#realTime").html(newUkTime);

    }

    setInterval(realUKTime(),1000);

输出::Mon 12月27日2021 12:6:3

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>

<p id="DateTimeBox">点击按钮显示日期和时间 <按钮onclick = " ShowDate ();">显示日期</button> . < >脚本 函数ShowDate() { . getelementbyid(“DateTimeBox”)。innerHTML = Date(); ｝ > < /脚本

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

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;
}

获取当前日期和时间

var now = new Date(); 
  var datetime = now.getFullYear()+'/'+(now.getMonth()+1)+'/'+now.getDate(); 
  datetime += ' '+now.getHours()+':'+now.getMinutes()+':'+now.getSeconds();