Develop Reference

javascript function to accept multiple date formats

Users want to use the following formats to enter dates:-
mm-dd-yyyy OR yyyy-mm-dd OR m-d-yy OR m-d-yyyy OR mm/dd/yyyy OR m/d/yy.
My plan is to capture whatever they enter and convert it to yyyy-mm-dd because that is the format that the date field value must be submitted. They have refused to use a calendar . I have tried the following JS function without any success. Any ideas?
var value = ctrl.getValue();
var date_input = new Date(value);
var day = date_input.getDay();
var month = date_input.getMonth() + 1;
var year = date_input.getFullYear();
var yyyy_MM_dd = year + "-" + month + "-" + day;
return yyyy_MM_dd

Because its wrong to use var day = date_input.getDay();
use it like this
var day = date_input.getDate();
function getDateFormat(value){
var date_input = new Date(value);
var day = date_input.getDate();
var month = date_input.getMonth() + 1;
var year = date_input.getFullYear();
var yyyy_MM_dd = year + "-" + month + "-" + day;
return yyyy_MM_dd;
}
console.log(getDateFormat("2017-12-30"));
console.log(getDateFormat("12-30-2017"));
.getDay is giving you days of weeks
Also be sure to use date format accepted by Date

Get clientside Date and Time format in Javascript

I want is, the formatted string as, MM/DD/YY or DD/MM/YYYY.
Which of these is set by client in his/her system.
How to get it?

var date = new Date();
var day = date.getDay();
var month = date.getMonth();
var year = date.getFullYear();
var final = day + "/" + month + "/" + year;
console.log(final); // "1/11/2015"
http://jsbin.com/zixacacuda/edit?js,console

var dt=new Date('2015-12-12');
var d=dt.getDay();
var m=dt.getMonth();
var y=dt.getFullYear();
var dtformated=d+'/'+m+'/'+y
console.log(dtformated)

var now = new Date().toLocaleDateString();
it willl retrun "12/28/2015 (MM/DD/YYYY)" format.

HTML5 get date string convert to date object

I try to use html5 type="date" and get the string and convert it to Date() in JS.
var dateString = $(this).prev().val();
var date = new Date(dateString);
var day = date.getDay();
var month = date.getMonth();
var year = date.getYear();
finalDate = day + "/" + month + "/" + year;
alert(finalDate);
But the result I got is different than what I've set, I have no idea what's wrong here :
I expect to get 18/05/1991
My demo is here http://jsfiddle.net/yL1q3ygf/

getMonth() returns a number between 0 and 11. You want to use getMonth()+1.
getDay() returns the day of the week, you want to use getDate() instead.

use getUTCDate(); before making it as an object (date).
var d = new Date(dateString);
var n = d.getUTCDate();
then use n in your code. it will work

$(function(){
$('button').click(function(){
var dateString = $(this).prev().val();
var date = new Date(dateString);
var day = date.getDate(); //day is for day of week. use date
var month = date.getMonth() +1; // months are zero based
var year = date.getFullYear(); //use full year for 4 digit year
finalDate = day + "/" + month + "/" + year;
alert(finalDate);
});
});
I updated your jsfiddle script
http://jsfiddle.net/yL1q3ygf/5/

Convert UTC Date to dd/mm/yyyy Format

I am having some difficulties when trying to convert UTC Date format to dd/mm/yyyy in JavaScript:
var launchDate = attributes["launch_date"];
if (isBuffering) {
var date = new Date(launchDate);
var d = new Date(date.toLocaleDateString());
launchDate = ((d.getUTCMonth() + 1) + "/" + (d.getUTCDate() + 1) + "/" + (d.getUTCFullYear()));
}
I tried with this, but it returns me an invalid date. So I changed to this:
var launchDate = attributes["launch_date"];
if (isBuffering) {
var date = new Date(launchDate);
var d = formatDate(new Date(date.toLocaleDateString()));
launchDate = ((d.getUTCMonth() + 1) + "/" + (d.getUTCDate() + 1) + "/" + (d.getUTCFullYear()));
}
However, it still returning me invalid Date. I wonder is there any possible way to change the date format of Fri May 31 2013 17:41:01 GMT+0200 (CEST) to dd/mm/yyyy?
Thanks in advance.

var d = new Date();
var n = d.toLocaleDateString();
This will be more superior in build JS method!

function formatDate(d)
{
date = new Date(d)
var dd = date.getDate();
var mm = date.getMonth()+1;
var yyyy = date.getFullYear();
if(dd<10){dd='0'+dd}
if(mm<10){mm='0'+mm};
return d = dd+'/'+mm+'/'+yyyy
}

Try it:
Date.parseExact(Your_Date, 'dd/MM/yyyy').toString('MM/dd/yyyy');
or
Date.parseExact(Your_Date, 'MM/dd/yyyy').toString('dd/MM/yyyy');

Month is 0 indexed, but day is not. You don't need to add 1 to your day.
Also, you're formatting it for MM/dd/yyyy, not dd/MM/yyyy.
solution:
var launchDate = attributes["launch_date"];
if (isBuffering) {
var date = new Date(launchDate);
var d = formatDate(new Date(date.toLocaleDateString()));
launchDate = ((d.getUTCDate())+ "/" + (d.getUTCMonth() + 1) + "/" + (d.getUTCFullYear()));
}

Get String in YYYYMMDD format from JS date object?

I'm trying to use JS to turn a date object into a string in YYYYMMDD format. Is there an easier way than concatenating Date.getYear(), Date.getMonth(), and Date.getDay()?

Altered piece of code I often use:
Date.prototype.yyyymmdd = function() {
var mm = this.getMonth() + 1; // getMonth() is zero-based
var dd = this.getDate();
return [this.getFullYear(),
(mm>9 ? '' : '0') + mm,
(dd>9 ? '' : '0') + dd
].join('');
};
var date = new Date();
date.yyyymmdd();

I didn't like adding to the prototype. An alternative would be:
var rightNow = new Date();
var res = rightNow.toISOString().slice(0,10).replace(/-/g,"");
<!-- Next line is for code snippet output only -->
document.body.innerHTML += res;

You can use the toISOString function :
var today = new Date();
today.toISOString().substring(0, 10);
It will give you a "yyyy-mm-dd" format.

Moment.js could be your friend
var date = new Date();
var formattedDate = moment(date).format('YYYYMMDD');

new Date('Jun 5 2016').
toLocaleString('en-us', {year: 'numeric', month: '2-digit', day: '2-digit'}).
replace(/(\d+)\/(\d+)\/(\d+)/, '$3-$1-$2');
// => '2016-06-05'

If you don't need a pure JS solution, you can use jQuery UI to do the job like this :
$.datepicker.formatDate('yymmdd', new Date());
I usually don't like to import too much libraries. But jQuery UI is so useful, you will probably use it somewhere else in your project.
Visit http://api.jqueryui.com/datepicker/ for more examples

This is a single line of code that you can use to create a YYYY-MM-DD string of today's date.
var d = new Date().toISOString().slice(0,10);

I don't like modifying native objects, and I think multiplication is clearer than the string padding the accepted solution.
function yyyymmdd(dateIn) {
var yyyy = dateIn.getFullYear();
var mm = dateIn.getMonth() + 1; // getMonth() is zero-based
var dd = dateIn.getDate();
return String(10000 * yyyy + 100 * mm + dd); // Leading zeros for mm and dd
}
var today = new Date();
console.log(yyyymmdd(today));
Fiddle: http://jsfiddle.net/gbdarren/Ew7Y4/

In addition to o-o's answer I'd like to recommend separating logic operations from the return and put them as ternaries in the variables instead.
Also, use concat() to ensure safe concatenation of variables
Date.prototype.yyyymmdd = function() {
var yyyy = this.getFullYear();
var mm = this.getMonth() < 9 ? "0" + (this.getMonth() + 1) : (this.getMonth() + 1); // getMonth() is zero-based
var dd = this.getDate() < 10 ? "0" + this.getDate() : this.getDate();
return "".concat(yyyy).concat(mm).concat(dd);
};
Date.prototype.yyyymmddhhmm = function() {
var yyyymmdd = this.yyyymmdd();
var hh = this.getHours() < 10 ? "0" + this.getHours() : this.getHours();
var min = this.getMinutes() < 10 ? "0" + this.getMinutes() : this.getMinutes();
return "".concat(yyyymmdd).concat(hh).concat(min);
};
Date.prototype.yyyymmddhhmmss = function() {
var yyyymmddhhmm = this.yyyymmddhhmm();
var ss = this.getSeconds() < 10 ? "0" + this.getSeconds() : this.getSeconds();
return "".concat(yyyymmddhhmm).concat(ss);
};
var d = new Date();
document.getElementById("a").innerHTML = d.yyyymmdd();
document.getElementById("b").innerHTML = d.yyyymmddhhmm();
document.getElementById("c").innerHTML = d.yyyymmddhhmmss();
<div>
yyyymmdd: <span id="a"></span>
</div>
<div>
yyyymmddhhmm: <span id="b"></span>
</div>
<div>
yyyymmddhhmmss: <span id="c"></span>
</div>

Local time:
var date = new Date();
date = date.toJSON().slice(0, 10);
UTC time:
var date = new Date().toISOString();
date = date.substring(0, 10);
date will print 2020-06-15 today as i write this.
toISOString() method returns the date with the ISO standard which is YYYY-MM-DDTHH:mm:ss.sssZ
The code takes the first 10 characters that we need for a YYYY-MM-DD format.
If you want format without '-' use:
var date = new Date();
date = date.toJSON().slice(0, 10).split`-`.join``;
In .join`` you can add space, dots or whatever you'd like.

Plain JS (ES5) solution without any possible date jump issues caused by Date.toISOString() printing in UTC:
var now = new Date();
var todayUTC = new Date(Date.UTC(now.getFullYear(), now.getMonth(), now.getDate()));
return todayUTC.toISOString().slice(0, 10).replace(/-/g, '');
This in response to #weberste's comment on #Pierre Guilbert's answer.

// UTC/GMT 0
document.write('UTC/GMT 0: ' + (new Date()).toISOString().slice(0, 19).replace(/[^0-9]/g, "")); // 20150812013509
// Client local time
document.write('<br/>Local time: ' + (new Date(Date.now()-(new Date()).getTimezoneOffset() * 60000)).toISOString().slice(0, 19).replace(/[^0-9]/g, "")); // 20150812113509

Another way is to use toLocaleDateString with a locale that has a big-endian date format standard, such as Sweden, Lithuania, Hungary, South Korea, ...:
date.toLocaleDateString('se')
To remove the delimiters (-) is just a matter of replacing the non-digits:
console.log( new Date().toLocaleDateString('se').replace(/\D/g, '') );
This does not have the potential error you can get with UTC date formats: the UTC date may be one day off compared to the date in the local time zone.

var someDate = new Date();
var dateFormated = someDate.toISOString().substr(0,10);
console.log(dateFormated);

dateformat is a very used package.
How to use:
Download and install dateformat from NPM. Require it in your module:
const dateFormat = require('dateformat');
and then just format your stuff:
const myYYYYmmddDate = dateformat(new Date(), 'yyyy-mm-dd');

Shortest
.toJSON().slice(0,10).split`-`.join``;
let d = new Date();
let s = d.toJSON().slice(0,10).split`-`.join``;
console.log(s);

Working from #o-o's answer this will give you back the string of the date according to a format string. You can easily add a 2 digit year regex for the year & milliseconds and the such if you need them.
Date.prototype.getFromFormat = function(format) {
var yyyy = this.getFullYear().toString();
format = format.replace(/yyyy/g, yyyy)
var mm = (this.getMonth()+1).toString();
format = format.replace(/mm/g, (mm[1]?mm:"0"+mm[0]));
var dd = this.getDate().toString();
format = format.replace(/dd/g, (dd[1]?dd:"0"+dd[0]));
var hh = this.getHours().toString();
format = format.replace(/hh/g, (hh[1]?hh:"0"+hh[0]));
var ii = this.getMinutes().toString();
format = format.replace(/ii/g, (ii[1]?ii:"0"+ii[0]));
var ss = this.getSeconds().toString();
format = format.replace(/ss/g, (ss[1]?ss:"0"+ss[0]));
return format;
};
d = new Date();
var date = d.getFromFormat('yyyy-mm-dd hh:ii:ss');
alert(date);
I don't know how efficient that is however, especially perf wise because it uses a lot of regex. It could probably use some work I do not master pure js.
NB: I've kept the predefined class definition but you might wanna put that in a function or a custom class as per best practices.

A little variation for the accepted answer:
function getDate_yyyymmdd() {
const date = new Date();
const yyyy = date.getFullYear();
const mm = String(date.getMonth() + 1).padStart(2,'0');
const dd = String(date.getDate()).padStart(2,'0');
return `${yyyy}${mm}${dd}`
}
console.log(getDate_yyyymmdd())

This guy here => http://blog.stevenlevithan.com/archives/date-time-format wrote a format() function for the Javascript's Date object, so it can be used with familiar literal formats.
If you need full featured Date formatting in your app's Javascript, use it. Otherwise if what you want to do is a one off, then concatenating getYear(), getMonth(), getDay() is probably easiest.

Little bit simplified version for the most popular answer in this thread https://stackoverflow.com/a/3067896/5437379 :
function toYYYYMMDD(d) {
var yyyy = d.getFullYear().toString();
var mm = (d.getMonth() + 101).toString().slice(-2);
var dd = (d.getDate() + 100).toString().slice(-2);
return yyyy + mm + dd;
}

You can simply use This one line code to get date in year
var date = new Date().getFullYear() + "-" + (parseInt(new Date().getMonth()) + 1) + "-" + new Date().getDate();

How about Day.js?
It's only 2KB, and you can also dayjs().format('YYYY-MM-DD').
https://github.com/iamkun/dayjs

Use padStart:
Date.prototype.yyyymmdd = function() {
return [
this.getFullYear(),
(this.getMonth()+1).toString().padStart(2, '0'), // getMonth() is zero-based
this.getDate().toString().padStart(2, '0')
].join('-');
};

This code is fix to Pierre Guilbert's answer:
(it works even after 10000 years)
YYYYMMDD=new Date().toISOString().slice(0,new Date().toISOString().indexOf("T")).replace(/-/g,"")

Answering another for Simplicity & readability.
Also, editing existing predefined class members with new methods is not encouraged:
function getDateInYYYYMMDD() {
let currentDate = new Date();
// year
let yyyy = '' + currentDate.getFullYear();
// month
let mm = ('0' + (currentDate.getMonth() + 1)); // prepend 0 // +1 is because Jan is 0
mm = mm.substr(mm.length - 2); // take last 2 chars
// day
let dd = ('0' + currentDate.getDate()); // prepend 0
dd = dd.substr(dd.length - 2); // take last 2 chars
return yyyy + "" + mm + "" + dd;
}
var currentDateYYYYMMDD = getDateInYYYYMMDD();
console.log('currentDateYYYYMMDD: ' + currentDateYYYYMMDD);

[day,,month,,year]= Intl.DateTimeFormat(undefined, { year: 'numeric', month: '2-digit', day: '2-digit' }).formatToParts(new Date()),year.value+month.value+day.value
or
new Date().toJSON().slice(0,10).replace(/\/|-/g,'')

From ES6 onwards you can use template strings to make it a little shorter:
var now = new Date();
var todayString = `${now.getFullYear()}-${now.getMonth()}-${now.getDate()}`;
This solution does not zero pad. Look to the other good answers to see how to do that.

I usually use the code below when I need to do this.
var date = new Date($.now());
var dateString = (date.getFullYear() + '-'
+ ('0' + (date.getMonth() + 1)).slice(-2)
+ '-' + ('0' + (date.getDate())).slice(-2));
console.log(dateString); //Will print "2015-09-18" when this comment was written
To explain, .slice(-2) gives us the last two characters of the string.
So no matter what, we can add "0" to the day or month, and just ask for the last two since those are always the two we want.
So if the MyDate.getMonth() returns 9, it will be:
("0" + "9") // Giving us "09"
so adding .slice(-2) on that gives us the last two characters which is:
("0" + "9").slice(-2)
"09"
But if date.getMonth() returns 10, it will be:
("0" + "10") // Giving us "010"
so adding .slice(-2) gives us the last two characters, or:
("0" + "10").slice(-2)
"10"

It seems that mootools provides Date().format(): https://mootools.net/more/docs/1.6.0/Types/Date
I'm not sure if it worth including just for this particular task though.

If you don't mind including an additional (but small) library, Sugar.js provides lots of nice functionality for working with dates in JavaScript.
To format a date, use the format function:
new Date().format("{yyyy}{MM}{dd}")