Develop Reference

Get System time, localstorage, compare dates and performe an action

I need to get the system time once, then store it on localStorage, then compare this stored value with a further system date and then perform an action if the future date is equal or greater than the one which is stored. I have tried but I am stucked in making the function which gets the system time the first time to run only once so I can get a future date to compare.
This is my code
console.log(formatTime());
function formatTime() {
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.getDay() + "/" + date.getMonth() + "/" + date.getFullYear() + " " + hours + ":" + minutes + ":" + seconds + " " + ampm);
}
document.getElementById("currentdt").innerHTML = strTime;
var strTime1 = formatTime();
var timeString = JSON.stringify(strTime1);
localStorage.setItem("strTime1", timeString);
var timeStringFromLocalStorage = localStorage.getItem("strTime1");
var timeFromLocalStorage = JSON.parse(timeStringFromLocalStorage);
document.getElementById("time").innerHTML = strTime1;
console.log(timeStringFromLocalStorage);
function compare(dateTimeA, dateTimeB) {
var momentA = moment(dateTimeA, "strTime1");
var momentB = moment(dateTimeB, "strTime");
if (momentA > momentB) return 1;
else if (momentA < momentB) return -1;
else return 0;
}
alert(compare("strTime1", "strTime"));

The function below will check if there has been a value set in localStorage. If there is no value set, it will set its first and stop the function.
If there is a value, then it will be turned into a moment instance and compared with the current date. If a difference in days is equal or larger to than specified it will redirect the page.
function redirectWhenOlderThan(days, url) {
const storedValue = localStorage.getItem('first-visit');
const now = moment();
/**
* If nothing is stored yet, then storedValue will be null.
* Here you will set the first localStorage item for the first time.
* Instead of a full date, store the timestamp.
* Then stop the function.
*/
if (storedValue === null) {
localStorage.setItem('first-visit', now.valueOf().toString());
return;
}
/**
* If there is a stored value then it will be a timestamp as a string.
* First parse it into a number before putting it into moment.
* Then check the difference in days between the dates.
*/
const then = moment(Number(storedValue));
const difference = now.diff(then, 'days');
/**
* If the difference is higher or equal to the given days, redirect.
*/
if (difference >= days) {
location.href = url;
}
}
Call the function with amount of days that should have passed since the first visit and the URL to redirect to.
redirectWhenOlderThan(15, 'https://example.com');
I hope this is what you meant.
Sidenote: dive into moment.js if you have the time. It has a lot of features that could spare you some time, like your formatTime() function, it can be written in a single line with moment.
moment().format('DD/MM/YYYY h:mm:ss A');

Now the final code goes like this
function formatTime() {
var date = new Date();
return strTime = date.getDay() + '/' + date.getMonth()+'/'+date.getFullYear();
}
document.getElementById("currentdt").innerHTML = strTime;
function redirectWhenOlderThan(days, url) {
const storedValue = localStorage.getItem('first-visit');
const now = moment();
if (storedValue === null) {
localStorage.setItem('first-visit', now.valueOf().toString());
return;
}
const then = moment(Number(storedValue));
const difference = now.diff(then, 'days');
if (difference >= days) {
location.href = url;
}
else {
window.location.href= 'app/phr.html';
}
}
setTimeout(function () {
redirectWhenOlderThan(1, 'app/licences.html');
}, 3000);

Javascript add hours to time

I have this javascript code which should show the time. It works. I wan't to be able to add extra time though. Lets say that I want to add 1 hour.
<script type="text/javascript">
Date.prototype.addHours = function(h) {
this.setTime(this.getTime() + (h*60*60*1000));
return this;
}
// This function gets the current time and injects it into the DOM
function updateClock() {
// Gets the current time
var now = new Date();
// Get the hours, minutes and seconds from the current time
var hours = now.getHours();
var minutes = now.getMinutes();
var seconds = now.getSeconds();
// Format hours, minutes and seconds
if (hours < 10) {
hours = "0" + hours;
}
if (minutes < 10) {
minutes = "0" + minutes;
}
if (seconds < 10) {
seconds = "0" + seconds;
}
// Gets the element we want to inject the clock into
var elem = document.getElementById('clock');
// Sets the elements inner HTML value to our clock data
elem.innerHTML = hours + ':' + minutes + ':' + seconds;
}
function start(){
setInterval('updateClock()', 200);
}
</script>
The first function calculates the milisecons that I want to add, and the second function is the "live clock". How do I implement the first function into the second one, so I get the working result?

for adding hours, use setHours :
// Gets the current time
var now = new Date();
console.log("actual time:", now);
now.setHours(now.getHours() + 1)
console.log("actual time + 1 hour:", now);
For references: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/setHours

Check out this fiddle.
The constructor Date(milliseconds) of class Date can be used here.
Here is the snippet.
var now = new Date();
alert(now);
var milliseconds = new Date().getTime() + (1 * 60 * 60 * 1000);
var later = new Date(milliseconds);
alert(later);

Check out this
fiddle here
var todayDate = new Date();
alert("After adding ONE hour : "+new Date(todayDate.setHours(todayDate.getHours()+1)) );

javascript date API is near to be completed, the existing methods of it can be use to add another functionality for this API, some says it is tedious but its not.
in order to add a method in a date we will access the prototype of this API,
like this.
Date.prototype.addTime = function(str){
function parse(str){
let arr = (typeof str == 'number')?[str]:str.split(":").map(t=>t.trim());
arr[0] = arr[0] || 0;
arr[1] = arr[1] || 0;
arr[2] = arr[2] || 0;
return arr
}
function arrToMill(arr){
let [h,m,s] = arr;
return (h*60*60*1000) + (m*60*1000) + (s*1000);
}
let date = new Date(this.getTime());
let parsed = parse(str);
date.setTime(date.getTime() + arrToMill(parsed));
return date;
}
getting it rockin.
this function is immutable
let date = new Date();
date.addTime(1);
date.addTime("01:00");`

Display 12-hour and 24-hour time

I want to make a webpage that displays the current time. When the "12-hour format" button is clicked, the time in 12-hour time will display in the div area. When the "24-hour format" button is clicked, the time will show in 24-hour time in the div area. Currently nothing happens when these buttons are clicked. Help!
HTML:
<html>
<head>
<title>Clock</title>
<script type="text/javascript" src="clock.js"></script>
</head>
<body>
<div id="textbox"></div>
<br/>
<button type="radio" onclick="getTwelveHrs()">12 Hour Format</button>
<button type="radio" onclick="getTwentyFourHrs()">24 Hour Format</button>
</body>
</html>
JavaScript:
function getTwelveHours{
if (i < 10) {
i = "0" + i;
}
return i;
}
function startTime() {
var today = new Date();
var h = today.getHours();
var m = today.getMinutes();
var s = today.getSeconds();
m = checkTime(m);
s = checkTime(s);
document.getElementById('textbox').innerHTML = h + ":" + m + ":" + s;
t = setTimeout(function () {
startTime()
}, 500);
}
startTime();
function getTwentyFourHrs() {
var today = new Date();
var h = today.getHours();
var m = today.getMinutes();
var s = today.getSeconds();
m = checkTime(m);
s = checkTime(s);
document.getElementById('textbox').innerHTML = h + ":" + m + ":" + s;
var t = setTimeout(function() {
startTime()
}, 500);
}
function checkTime(i) {
if (i < 10) {
i = "0" + i
};
return i;
}

Why dont you just use a library like Moment.js to do this for you.
http://momentjs.com/docs/
H, HH 24 hour time
h, or hh 12 hour time (use in conjunction with a or A)
so just use this code in JavaScript when using moment.js
the moment() method returns the current date in your specific format. So when you the user clicks the button you can call the following method on each button
moment().format("YYYY-MM-DD HH:mm"); // 24H clock
moment().format("YYYY-MM-DD hh:mm"); // 12H clock
Havn't tested this , but it should work

The 12 hour format can be obtained by using moment js a good library for performing time & date operations.
moment().format('YYYY-MM-DD, hh:mm:ss A')
where Post or ante meridiem (Note the only one of the character a p are also considered valid)
Link for Moment Js :-
https://momentjs.com

Agreed with others, yes issues with that code but for time conversion part - maybe you could do something simple like this using JavaScript built-in functions :
For 12-hr Format :
let formattedTime = new Date().toLocaleTimeString('en-US');
console.log(formattedTime)
For 24-hr Format :
let currentDateTime = new Date();
let formattedTime = currentDateTime.getHours() + ":" + currentDateTime.getMinutes() +":" + currentDateTime.getSeconds();
console.log(formattedTime)

const time = new Date().getHours('en-US',{hour12:false});
const time = new Date().getHours('en-US',{hour12:true});

To be perfectly honest, I'm not entirely sure how you were trying to make this happen, but I think I understand what you wanted to have happen.
Give this a try:
window.onload = function() {
var h, m, s;
document.getElementById('twelveHrs').style.display = 'none';
document.getElementById('twentyFourHrs').style.display = 'none';
getTwelveHrs();
getTwentyFourHrs();
function getTwelveHrs() {
var tag = 'AM';
checkTime();
if(h > 12) {
h -= 12
tag = 'PM';
}
document.getElementById('twelveHrs').innerHTML = h + ':' + m + ':' + s + ' ' + tag;
t = setTimeout(function() {
getTwelveHrs()
}, 1000);
}
function getTwentyFourHrs() {
checkTime();
document.getElementById('twentyFourHrs').innerHTML = h + ':' + m + ':' + s;
var t = setTimeout(function() {
getTwentyFourHrs()
}, 1000);
}
function checkTime() {
var today = new Date();
h = today.getHours();
m = today.getMinutes();
s = today.getSeconds();
if(h < 10)
h = '0' + h;
if(m < 10)
m = '0' + m;
if(s < 10)
s = '0' + s;
return h, m, s;
}
}
function displayTwelveHrs() {
document.getElementById('twentyFourHrs').style.display = 'none';
document.getElementById('twelveHrs').style.display = '';
}
function displayTwentyFourHrs() {
document.getElementById('twelveHrs').style.display = 'none';
document.getElementById('twentyFourHrs').style.display = '';
}
Then replace your HTML with:
<div id="twelveHrs"></div>
<div id="twentyFourHrs"></div>
<br />
<button type="radio" onclick="displayTwelveHrs()">12 Hour Format</button>
<button type="radio" onclick="displayTwentyFourHrs()">24 Hour Format</button>
Basically, when the page loads, it'll start the clocks and hide the corresponding div tags. Then you click a button, it will then display the div you want while hiding the other.
A working JSFiddle can be found at: http://jsfiddle.net/fp3Luwzc/

Since deadline at work is coming and right now is really just around the corner, I have decided to answer this 5 years old question.
Most people recommended using Moment.js library, which is really fine, because in most cases there is no point in reinventing the wheel and trusting a library with 9,897,199 weekly npm downloads is without any doubts a sane choice.
However, since the only answer providing solution based on OP's code seems to have some bugs in it; I would like to humbly propose my solution:
const FORMATS = {
TwelveHours: 12,
TwentyFourHours: 24
}
class Clock {
format = FORMATS.TwentyFourHours;
constructor(clockDivId) {
this.clockDivId = clockDivId;
this.clockInterval = setInterval(() => {
document.getElementById(clockDivId).innerHTML = this.getCurrentTime().format(this.format);
}, 500)
}
getCurrentTime() {
let today = new Date();
return new Time(today.getHours(), today.getMinutes(), today.getSeconds());
}
switchTo12HourFormat() {
this.format = FORMATS.TwelveHours
}
switchTo24HourFormat() {
this.format = FORMATS.TwentyFourHours
}
destroy() {
clearInterval(this.clockInterval);
}
}
class Time {
constructor(hours, minutes, seconds) {
this.hours = hours;
this.minutes = minutes;
this.seconds = seconds;
}
format(type) {
switch (type) {
case FORMATS.TwentyFourHours: {
return this.print(this.hours)
}
case FORMATS.TwelveHours: {
let tag = this.hours >= 12 ? 'p.m' : 'a.m';
let hours = this.hours % 12;
if (hours == 0) {
hours = 12;
}
return this.print(hours) + ' ' + tag;
}
}
}
//private
to2Digits(number) {
return number < 10 ? '0' + number : '' + number;
}
print(hours) {
return this.to2Digits(hours) + ':' + this.to2Digits(this.minutes) + ':' + this.to2Digits(this.seconds);
}
}
let clock = new Clock("clock");
<html>
<head>
<title>Clock</title>
</head>
<body>
<div id="clock"></div>
<br/>
<button onclick="clock.switchTo12HourFormat()">12 Hour Format</button>
<button onclick="clock.switchTo24HourFormat();">24 Hour Format</button>
</body>
</html>
Oh no, oh forking no! I have written "print" instead of "this.print" and I've run it in Google Chrome.
Basically UI got blocked by print dialog and I've lost all the code and had to write it again and now I am going home to enjoy some sleep and maybe, maybe one episode of HIMYM.

Javascript countdown every day

I need to make countdown timer for every day to 21:00. Counting till live stream.
If time is less then 21:00 display the time left and if time is from 21:00-22:00
I would like to display 'streaming right now'. After 22:00 start counting till tomorrow at 21:00.
Any suggestins how to do this?
Here is what I tried so far but it doesn't work well and also if client change the time on his computer the counter will change. I need to fix that on server side so for everyone it will show the same time.
<script type="text/javascript">
$(document).ready(function(){
var curT, tarT, difT;
curT = new Date().getTime()/1000;
tarT = new Date('<?php echo (new DateTime('May 05, 2014'))->add(new DateInterval("P1D"))->format('M d, Y');?>, 21:00:00').getTime()/1000;
init();
function init(){
var d,h,m,s;
difT = tarT - curT;
function updateT(){
s = difT;
d = Math.floor(s/86400);
s -= d * 86400;
h = Math.floor(s/3600);
s -= h * 3600;
m = Math.floor(s/60);
s -= m * 60;
s = Math.floor(s);
}
function tick(){
clearTimeout(timer);
updateT();
displayT();
if(difT>0){
difT--;
timer = setTimeout(tick,1*1000);
} else {
$('.timeleft').html('Aukcija u toku...');
}
}
function displayT(){
var out;
out = h+":"+m+":"+s;
$('.timeleft').html(out);
}
var timer = setTimeout(tick,1*1000);
}
});
</script>

Since you need a combination of both scripts from above, I combined them for you: http://jsfiddle.net/69TAf/
Reads out the real time from GMT Server
Clients timezone doesn't matter
GMT Server is only pinged once at beginning (for better performance)
Added leading zeros so it looks better
Credits to edcs and Miskone!
var date;
var display = document.getElementById('time');
$(document).ready(function() {
getTime('GMT', function(time){
date = new Date(time);
});
});
setInterval(function() {
date = new Date(date.getTime() + 1000);
var currenthours = date.getHours();
var hours;
var minutes;
var seconds;
if (currenthours != 21){
if (currenthours < 21) {
hours = 20 - currenthours;
} else {
hours = 21 + (24 - currenthours);
}
minutes = 60 - date.getMinutes();
seconds = 60 - date.getSeconds();
if (minutes < 10) {
minutes = '0' + minutes;
}
if (seconds < 10) {
seconds = '0' + seconds;
}
display.innerHTML = hours + ':' + minutes + ':' +seconds;
} else {
display.innerHTML = 'LIVE NOW';
}
}, 1000);
function getTime(zone, success) {
var url = 'http://json-time.appspot.com/time.json?tz=' + zone,
ud = 'json' + (+new Date());
window[ud]= function(o){
success && success(new Date(o.datetime));
};
document.getElementsByTagName('head')[0].appendChild((function(){
var s = document.createElement('script');
s.type = 'text/javascript';
s.src = url + '&callback=' + ud;
return s;
})());
}
And html:
<div id='time'></div>
If you don't want to ping an external server for getting the time, you can use this fiddle (not working on jsfiddle, since contains php):
http://jsfiddle.net/qQ6V3/ - I think it's even better this way.

If you need everyone to be counting down from the same time, then you'll need to grab it from a centralised time server. This code does exactly that:
function getTime(zone, success) {
var url = 'http://json-time.appspot.com/time.json?tz=' + zone,
ud = 'json' + (+new Date());
window[ud]= function(o){
success && success(new Date(o.datetime));
};
document.getElementsByTagName('head')[0].appendChild((function(){
var s = document.createElement('script');
s.type = 'text/javascript';
s.src = url + '&callback=' + ud;
return s;
})());
}
getTime('GMT', function(time){
// This is where you do whatever you want with the time:
alert(time);
});
Source
If you use getTime() instead of grabbing the local time from the client then everyone will be in sync.

you can do something like this :
<div id='time'></div>
and the script :
var display = document.getElementById('time');
setInterval(function(){
var date = new Date();
var currenthours = date.getHours();
var hours;
var minutes;
var secondes;
if (currenthours != 21){
if (currenthours < 21)
hours = 20 - currenthours;
else hours = 21 + (24 - currenthours);
minutes = 60 - date.getMinutes();
secondes = 60 - date.getSeconds();
display.innerHTML = hours + ':' + minutes + ':' +secondes;
}
else display.innerHTML = 'LIVE NOW';
},1000);
fiddle: http://jsfiddle.net/KbM8D/

Lots of answers, one more won't hurt. :-)
I think you are best to pass the start and end of streaming to the client as a UNIX UTC time values in seconds. Then the client can turn that into a local date and count down to that. Using a network time server sounds good, but it means that everyone must use the same time server and you are reliant on the server being available.
if you're going to pass a time at all, it might as well be the start and end according to your server. You can even pass the current time from the server and calculate a time offset to apply at the client. Anyhow, the code…
<script>
var countDown = (function() {
var startStream;
var endStream;
var streamingText = 'streaming right now';
var updateElement;
// Pad single digit numbers
function pad(n) {
return (n<10?'0':'') + +n;
}
// Format a time difference as hh:mm:ss
// d0 and d1 are date objects, d0 < d1
function timeDiff(d0, d1) {
var diff = d1 - d0;
return pad(diff/3.6e6|0) + ':' + pad((diff%3.6e6)/6e4|0) + ':' + pad(diff%6e4/1000|0);
}
// start, end are UNIX UTC time values in seconds for the start and end of streaming
return function(elementId, start, end) {
var now = new Date();
var returnValue;
// By default, run again just after next full second
var delay = 1020 - now.getMilliseconds();
// turn start and end times into local Date objects
if (start) startStream = new Date(start*1000);
if (end) endStream = new Date(end*1000);
// If now is after endStream, add 1 day,
// Use UTC to avoid daylight saving adjustments
if (now > endStream) {
endStream.setUTCHours(endStream.getUTCHours() + 24);
startStream.setUTCHours(startStream.getUTCHours() + 24);
}
// Store the element to write the text to
if (elementId) updateElement = document.getElementById(elementId);
// If it's streaming time, return streaming text
if (now >= startStream && now < endStream) {
returnValue = streamingText;
// Run again after streaming end time
delay = endStream - now;
} else {
// Otherwise, count down to startStream
returnValue = timeDiff(now, startStream);
}
// Write the time left or streaming text
updateElement.innerHTML = returnValue;
// Call again when appropriate
setTimeout(countDown, delay);
};
}());
// Testing code
// Create dates for a local time of 21:00 today
var myStart = new Date();
myStart.setHours(21,0,0,0);
var myEnd = new Date()
myEnd.setHours(22,0,0,0);
// Create UNIX time values for same time as UTC
var startUTCTimeValue = myStart/1000|0
var endUTCTimeValue = myEnd/1000|0
// Run when page loads
window.onload = function() {
countDown('foo', startUTCTimeValue, endUTCTimeValue);
}
</script>
<div id="foo"></div>

How to show current time in JavaScript in the format HH:MM:SS?

How do I show the current time in the format HH:MM:SS?

You can use native function Date.toLocaleTimeString():
var d = new Date();
var n = d.toLocaleTimeString();
This will display e.g.:
"11:33:01"
MDN: Date toLocaleTimeString
var d = new Date();
var n = d.toLocaleTimeString();
alert("The time is: \n"+n);

function checkTime(i) {
if (i < 10) {
i = "0" + i;
}
return i;
}
function startTime() {
var today = new Date();
var h = today.getHours();
var m = today.getMinutes();
var s = today.getSeconds();
// add a zero in front of numbers<10
m = checkTime(m);
s = checkTime(s);
document.getElementById('time').innerHTML = h + ":" + m + ":" + s;
t = setTimeout(function() {
startTime()
}, 500);
}
startTime();
<div id="time"></div>
DEMO using javaScript only
Update
Updated Demo
(function () {
function checkTime(i) {
return (i < 10) ? "0" + i : i;
}
function startTime() {
var today = new Date(),
h = checkTime(today.getHours()),
m = checkTime(today.getMinutes()),
s = checkTime(today.getSeconds());
document.getElementById('time').innerHTML = h + ":" + m + ":" + s;
t = setTimeout(function () {
startTime()
}, 500);
}
startTime();
})();

You can do this in Javascript.
var time = new Date();
console.log(time.getHours() + ":" + time.getMinutes() + ":" + time.getSeconds());
At present it returns 15:5:18. Note that if any of the values are less than 10, they will display using only one digit, not two.
Check this in JSFiddle
Updates:
For prefixed 0's try
var time = new Date();
console.log(
("0" + time.getHours()).slice(-2) + ":" +
("0" + time.getMinutes()).slice(-2) + ":" +
("0" + time.getSeconds()).slice(-2));

You can use moment.js to do this.
var now = new moment();
console.log(now.format("HH:mm:ss"));
Outputs:
16:30:03

new Date().toTimeString().slice(0,8)
Note that toLocaleTimeString() might return something like 9:00:00 AM.

Use this way:
var d = new Date();
localtime = d.toLocaleTimeString('en-US', { hour12: false });
Result: 18:56:31

function realtime() {
let time = moment().format('h:mm:ss a');
document.getElementById('time').innerHTML = time;
setInterval(() => {
time = moment().format('h:mm:ss a');
document.getElementById('time').innerHTML = time;
}, 1000)
}
realtime();
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.22.1/moment.min.js"></script>
<div id="time"></div>
A very simple way using moment.js and setInterval.
setInterval(() => {
moment().format('h:mm:ss a');
}, 1000)
Sample output
Using setInterval() set to 1000ms or 1 second, the output will refresh every 1 second.
3:25:50 pm
This is how I use this method on one of my side projects.
setInterval(() => {
this.time = this.shared.time;
}, 1000)
Maybe you're wondering if using setInterval() would cause some performance issues.
Is setInterval CPU intensive?
I don't think setInterval is inherently going to cause you significant performance problems. I suspect the reputation may come from an earlier era, when CPUs were less powerful. ... - lonesomeday
No, setInterval is not CPU intensive in and of itself. If you have a lot of intervals running on very short cycles (or a very complex operation running on a moderately long interval), then that can easily become CPU intensive, depending upon exactly what your intervals are doing and how frequently they are doing it. ... - aroth
But in general, using setInterval really like a lot on your site may slow down things. 20 simultaneously running intervals with more or less heavy work will affect the show. And then again.. you really can mess up any part I guess that is not a problem of setInterval. ... - jAndy

new Date().toLocaleTimeString('it-IT')
The it-IT locale happens to pad the hour if needed and omits PM or AM 01:33:01

Compact clock function:
setInterval(function() {
let d = new Date()
console.log(`${d.getHours()}:${d.getMinutes()}:${d.getSeconds()}`)
}, 1000);

This code will output current time in HH:MM:SS format in console, it takes into account GMT timezones.
var currentTime = Date.now()
var GMT = -(new Date()).getTimezoneOffset()/60;
var totalSeconds = Math.floor(currentTime/1000);
seconds = ('0' + totalSeconds % 60).slice(-2);
var totalMinutes = Math.floor(totalSeconds/60);
minutes = ('0' + totalMinutes % 60).slice(-2);
var totalHours = Math.floor(totalMinutes/60);
hours = ('0' + (totalHours+GMT) % 24).slice(-2);
var timeDisplay = hours + ":" + minutes + ":" + seconds;
console.log(timeDisplay);
//Output is: 11:16:55

This is an example of how to set time in a div(only_time) using javascript.
function date_time() {
var date = new Date();
var am_pm = "AM";
var hour = date.getHours();
if(hour>=12){
am_pm = "PM";
}
if (hour == 0) {
hour = 12;
}
if(hour>12){
hour = hour - 12;
}
if(hour<10){
hour = "0"+hour;
}
var minute = date.getMinutes();
if (minute<10){
minute = "0"+minute;
}
var sec = date.getSeconds();
if(sec<10){
sec = "0"+sec;
}
document.getElementById("time").innerHTML = hour+":"+minute+":"+sec+" "+am_pm;
}
setInterval(date_time,500);
<per>
<div class="date" id="time"></div>
</per>

new Date().toLocaleTimeString()

function realtime() {
let time = moment().format('hh:mm:ss.SS a').replace("m", "");
document.getElementById('time').innerHTML = time;
setInterval(() => {
time = moment().format('hh:mm:ss.SS A');
document.getElementById('time').innerHTML = time;
}, 0)
}
realtime();
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.22.1/moment.min.js"></script>
<div id="time"></div>

Use
Date.toLocaleTimeString()
// Depending on timezone, your results will vary
const event = new Date('August 19, 1975 23:15:30 GMT+00:00');
console.log(event.toLocaleTimeString('en-US'));
// expected output: 1:15:30 AM
console.log(event.toLocaleTimeString('it-IT'));
// expected output: 01:15:30
console.log(event.toLocaleTimeString('ar-EG'));
// expected output: ١٢:١٥:٣٠
Source