Day Name from Date in JS

I need to display the name of the day given a date (like "05/23/2014") which I get from a 3rd party.

I've tried using Date, but I only get the date.

What is the correct way to get the name of the day?

Ahum, three years later...

Why nobody uses the methods provided by the standard javascript Date class (except Callum Linington)?

See https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Date/toLocaleDateString

Getting the day name from a date:

function getDayName(dateStr, locale)
{
	var date = new Date(dateStr);
	return date.toLocaleDateString(locale, { weekday: 'long' });		
}

var dateStr = '05/23/2014';
var day = getDayName(dateStr, "nl-NL"); // Gives back 'Vrijdag' which is Dutch for Friday.

Getting all weekdays in an array:

function getWeekDays(locale)
{
	var baseDate = new Date(Date.UTC(2017, 0, 2)); // just a Monday
	var weekDays = [];
	for(i = 0; i < 7; i++)
	{		
		weekDays.push(baseDate.toLocaleDateString(locale, { weekday: 'long' }));
		baseDate.setDate(baseDate.getDate() + 1);		
	}
	return weekDays;
}

var weekDays = getWeekDays('nl-NL'); // Gives back { 'maandag', 'dinsdag', 'woensdag', 'donderdag', 'vrijdag', 'zaterdag', 'zondag'} which are the days of the week in Dutch.

For American dates use 'en-US' as locale.

You could use the Date.getDay() method, which returns 0 for sunday, up to 6 for saturday. So, you could simply create an array with the name for the day names:

var days = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'];
var d = new Date(dateString);
var dayName = days[d.getDay()];

Here dateString is the string you received from the third party API.

Alternatively, if you want the first 3 letters of the day name, you could use the Date object's built-in toString method:

var d = new Date(dateString);
var dayName = d.toString().split(' ')[0];

That will take the first word in the d.toString() output, which will be the 3-letter day name.

use the Date.toLocaleString() method :

new Date(dateString).toLocaleString('en-us', {weekday:'long'})

let weekday = ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'][new Date().getDay()]

To get the day from any given date, just pass the date into a new Date object:

let date = new Date("01/05/2020");
let day = date.toLocaleString('en-us', {weekday: 'long'});
console.log(day);
// expected result = tuesday

To read more, go to mdn-date.prototype.toLocaleString()(https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/toLocaleString)

var days = [
    "Sunday",
    "Monday",
    "...", //etc
    "Saturday"
];

console.log(days[new Date().getDay()]);

Simple, read the Date object in JavaScript manual

To do other things with date, like get a readable string from it, I use:

var d = new Date();
d.toLocaleString();

If you just want time or date use:

d.toLocaleTimeString();
d.toLocaleDateString();

You can parse dates either by doing:

var d = new Date(dateToParse);

or

var d = Date.parse(dateToParse);

let weekday = new Date(dateString).toLocaleString('en-us', {weekday:'long'});
console.log('Weekday',weekday);

Take a look at this :

var event = new Date(Date.UTC(2012, 11, 20, 3, 0, 0));

var options = { weekday: 'long', year: 'numeric', month: 'long', day: 'numeric' };

console.log(event.toLocaleDateString('de-DE', options));
// expected output: Donnerstag, 20. Dezember 2012

console.log(event.toLocaleDateString('ar-EG', options));
// expected output: الخميس، ٢٠ ديسمبر، ٢٠١٢

console.log(event.toLocaleDateString('ko-KR', options));
// expected output: 2012년 12월 20일 목요일

Source : Mozilla Doc

One line solution :

const day = ["sunday","monday","tuesday","wednesday","thursday","friday","saturday"][new Date().getDay()]

Easiest and simplest way:

var days = ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"];
var dayName = days[new Date().getDay()];

Try using this code:

var event = new Date();
var options = { weekday: 'long' };
console.log(event.toLocaleDateString('en-US', options));

this will give you the day name in string format.

I'm not a fan of over-complicated solutions if anyone else comes up with something better, please let us know :)

any-name.js

var today = new Date().toLocaleDateString(undefined, {
	day: '2-digit',
	month: '2-digit',
	year: 'numeric',
	weekday: 'long'
});

any-name.html
<script>
	document.write(today);
</script>

Solution No.1

var today = new Date();

  var day = today.getDay();

  var days = ["Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"];

  var dayname = days[day];

  document.write(dayname);

Solution No.2

	  var today = new Date();

  var day = today.getDay();

  switch(day){
    case 0:
    day = "Sunday";
    break;

    case 1:
    day = "Monday";
    break;

    case 2:
    day ="Tuesday";
    break;

    case 3:
    day = "Wednesday";
    break;

    case 4:
    day = "Thrusday";
    break;

    case 5:
    day = "Friday";
    break;

    case 6:
    day = "Saturday";
    break;
  }


document.write(day);

Shortest one liner

Change the UTC day from 6 to 5 if you want Array to start from Sunday.

const getWeekDays = (locale) => [...Array(7).keys()].map((v)=>new Date(Date.UTC(1970, 0, 6+v)).toLocaleDateString(locale, { weekday: 'long' }));

console.log(getWeekDays('de-DE')); 

One more option is to use the inbuilt function Intl.DateTimeFormat, e.g.:

const getDayName = (dateString) =>
  new Intl.DateTimeFormat('en-Us', { weekday: 'long' }).format(new Date(dateString));

<label for="inp">Enter a date string in the format "MM/DD/YYYY" or "YYYY-MM-DD" and press "OK":</label><br>
<input type="text" id="inp" value="01/31/2021">
<button onclick="alert(getDayName(document.getElementById('inp').value))">OK</button>

var dayName =['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'];
var day = dayName[new Date().getDay()];
console.log(day)

you can use an object

var days = {
   'Mon': 'Monday',
   'etc..': 'etc..',
   'Fri': 'Friday'
}

var date = new Date().toString().split(' ')[0]; //get day abreviation first
console.log(days[date]);

var date = new Date(Date.UTC(2012, 11, 20, 3, 0, 0));

// request a weekday along with a long date
var options = { weekday: 'long', year: 'numeric', month: 'long', day: 'numeric' };
console.log(date.toLocaleDateString('de-DE', options));
// → "Donnerstag, 20. Dezember 2012"

// an application may want to use UTC and make that visible
options.timeZone = 'UTC';
options.timeZoneName = 'short';
console.log(date.toLocaleDateString('en-US', options));
// → "Thursday, December 20, 2012, UTC"

Just use it:

function getWeekDayNames(format = 'short', locale = 'ru') {
  const names = [];
  const date = new Date('2020-05-24');
  let days = 7;

  while (days !== 0) {
    date.setDate(date.getDate() + 1);
    names.push(date.toLocaleDateString(locale, { weekday: format }));
    days--;
  }

  return names;
}

About formats you can read here Documentation DateTimeFormat

Not the best method, use an array instead. This is just an alternative method.

http://www.w3schools.com/jsref/jsref_getday.asp

var date = new Date();
var day = date.getDay();

You should really use google before you post here.

Since other people posted the array method I'll show you an alternative way using a switch statement.

switch(day) {
    case 0:
        day = "Sunday";
        break;
    case 1:
        day = "Monday";
        break;

    ... rest of cases

    default:
        // do something
        break;
}

The above works, however, the array is the better alternative. You may also use if() statements however a switch statement would be much cleaner then several if's.

I solved this problem in this way. Hope that may help you

let dateString = '5/23/2014'  

// converting Date String to Javascript Date Format
let day = new Date(dateString).getDay();
let month = new Date(dateString).getMonth()
let year =  new Date(dateString).getFullYear()
let dayName;

if (day ==0){
    dayName= 'Sunday'
}else if (day == 1){
    dayName= 'Monday'
}else if (day == 2){
    dayName= 'Tuesday'
}else if (day == 3){
    dayName= 'Wednesday'
}else if (day == 4){
    dayName= 'Thursday'
}else if (day ==5){
    dayName= 'Friday'
}else {
    dayName= 'Saturday'
}

console.log(`Day : ${dayName} Month: ${month+1} Year : ${year}`)