Here is the List I found, not exhaustive though.
- https://html-shark.com/HTML/LanguageCodes.htm (Covers a lot)
- http://www.lingoes.net/en/translator/langcode.htm (backup)
EDITED: a more comprehensive list https://gist.github.com/mlconnor/1887156
Answer from Adeyemi Simeon on Stack OverflowMDN Web Docs
developer.mozilla.org › en-US › docs › Web › JavaScript › Reference › Global_Objects › Date › toLocaleDateString
Date.prototype.toLocaleDateString() - JavaScript | MDN
The toLocaleDateString() method of Date instances returns a string with a language-sensitive representation of the date portion of this date in the local timezone. In implementations with Intl.DateTimeFormat API support, this method delegates to Intl.DateTimeFormat.
W3Schools
w3schools.com › jsref › jsref_tolocaledatestring.asp
W3Schools.com
The toLocaleDateString() method returns the date (not the time) of a date object as a string, using locale conventions.
Substack
patrickojeh.substack.com › p › a-guide-to-formatting-dates-with
A Guide to Formatting Dates with toLocaleDateString in ...
January 10, 2025 - In the event you want more control, that’s where specifying locales comes in. ... The first parameter of toLocaleDateString() is the locale string — which would be en-US for American English, en-GB for British English, or ja-JP for Japanese.
Medium
medium.com › geekculture › level-up-your-date-and-time-formatting-skills-in-javascript-866d8b656092
Level Up Your Date and Time Formatting Skills in JavaScript | by Danielle Dias | Geek Culture | Medium
May 26, 2023 - The simplest usage of toLocaleDateString() involves providing just the locale parameter.
Codecademy
codecademy.com › docs › javascript › dates › .tolocaledatestring()
JavaScript | Dates | .toLocaleDateString() | Codecademy
June 2, 2023 - It is translated to a specific language according to an event’s locale and other options. ... Front-end engineers work closely with designers to make websites beautiful, functional, and fast. ... Learn how to use JavaScript — a powerful and flexible programming language for adding website interactivity. Beginner Friendly.Beginner Friendly15 hours15 hours · const myEventDate = new Date('December 31, 2021'); ... When used without any parameters, .toLocaleDateString() returns a string with the month, day, and year options defaulted to numeric.
GeeksforGeeks
geeksforgeeks.org › javascript › javascript-date-tolocaledatestring-method
JavaScript Date toLocaleDateString() Method - GeeksforGeeks
July 11, 2025 - Returns a date as a string value in a specific format that is specified by the locale. Note: The dateObj should be a valid Date object. Example 1: Formatting Date with JavaScript's toLocaleDateString()
MDN Web Docs
developer.mozilla.org › en-US › docs › Web › JavaScript › Reference › Global_Objects › Date › toLocaleString
Date.prototype.toLocaleString() - JavaScript | MDN
October 30, 2025 - // An application may want to use UTC and make that visible options.timeZone = "UTC"; options.timeZoneName = "short"; console.log(date.toLocaleString("en-US", options)); // Example output: "Thursday, December 20, 2012 at UTC" // Sometimes even the US needs 24-hour time console.log(date.toLocaleString("en-US", { hour12: false })); // Example output: "12/19/2012, 19:00:00" // The exact date and time may shift depending on your local time zone. Intl.DateTimeFormat · Date.prototype.toLocaleDateString() Date.prototype.toLocaleTimeString() Date.prototype.toString() Was this page helpful to you?
TutorialsPoint
tutorialspoint.com › javascript › date_tolocaledatestring.htm
JavaScript Date toLocaleDateString() Method
The toLocaleDateString() method returns a string representing the date portion of the given Date object according to the locale-specific conventions and formatting options.
Top answer 1 of 2
6
I'd recommend any JavaScript date library in conjunction with UserContext.dateFormat. As you say, browser locale implementations are pretty brittle. The display on the client should be completely independent of the underlying value and whether or not it was remoted :-)
Edit: or carefully take advantage of the DateUtil object already present (courtesy @TehNrd)
From the comments:
DateUtil.getDateTimeStringFromUserLocale(d); and DateUtil.getDateStringFromUserLocale(d); I'd recommend wrapping them in a try catch as they could change at anytime.
2 of 2
4
Use DateFormat.js to convert date into any user locale format. To get the user locale in apex
UserInfo.getLocale()
Codeproject
reference.codeproject.com › javascript
javascript Date.prototype.toLocaleDateString() - CodeProject Reference
November 5, 2021 - In basic use without specifying a locale, a formatted string in the default locale and with default options is returned. ... var date = new Date(Date.UTC(2012, 11, 12, 3, 0, 0)); // toLocaleDateString() without arguments depends on the implementation, // the default locale, and the default time zone console.log(date.toLocaleDateString()); // → "12/11/2012" if run in en-US locale with time zone America/Los_Angeles
Medium
medium.com › swlh › use-tolocaledatestring-to-format-javascript-dates-2959108ea020
Use toLocaleDateString to Format JavaScript Dates | by John Au-Yeung | The Startup | Medium
April 5, 2020 - The locales and options arguments let applications specify the language that should be used to format the dates and set other options to format dates as we wish. ... const date = new Date(2019,1,1,1,1,1); const options = { weekday: 'long', year: 'numeric', month: 'long', day: 'numeric' }; console.log(date.toLocaleDateString('de-DE', options));
Stack Overflow
stackoverflow.com › questions › 36089937 › date-input-and-tolocaledatestring-using-different-locales
Date input and toLocaleDateString using different locales
Chrome language is set to Canadian, ... thought toLocaleDateString() would pick up Canada as my locale and format the date appropriately. ... locales (Optional). An array of locale strings that contain one or more language or locale tags. If you ...
Reality Ripple
udn.realityripple.com › docs › Web › JavaScript › Reference › Global_Objects › Date › toLocaleDateString
Date.prototype.toLocaleDateString() - JavaScript
In basic use without specifying a locale, a formatted string in the default locale and with default options is returned. var date = new Date(Date.UTC(2012, 11, 12, 3, 0, 0)); // toLocaleDateString() without arguments depends on the implementation, // the default locale, and the default time zone console.log(date.toLocaleDateString()); // → "12/11/2012" if run in en-US locale with time zone America/Los_Angeles
GitHub
github.com › nodejs › node › issues › 45945
ToLocaleDateString inconsistent/wrong output locale to "en-CA" · Issue #45945 · nodejs/node
September 2, 2022 - To get the format YYYY-MM-DD you could return to node 19.0.0 or use 'sv-SE' locale instead
Author crowrvo
Elijah Manor
elijahmanor.com › blog › format-js-dates-and-times
Natively Format JavaScript Dates and Times
July 20, 2020 - const date = new Date() console.log(date.toLocaleDateString('en-US')) // 7/19/2020 const dateOptions = { weekday: 'long', year: 'numeric', month: 'long', day: 'numeric', } console.log(date.toLocaleDateString('en-US', dateOptions)) // Sunday, July 19, 2020 console.log( date.toLocaleDateString('en-US', { month: 'short', day: 'numeric', }) ) // Jul 19 console.log( date.toLocaleDateString('fr-FR', { month: 'long', }) ) // juillet · Occasionally, you just need to output the time portion of a JavaScript Date object. Fortunately, in cases like these, you can use the toLocaleTimeString method. Not only does this method support locale, like the corresponding toLocaleDateString method, but it also supports a timeZone option!
JavaScript in Plain English
javascript.plainenglish.io › javascript-date-object-locale-methods-to-format-the-date-string-5e3be8343db5
JavaScript Date Object: LOCALE Methods to FORMAT the Date String | by Jakub Korch | JavaScript in Plain English
July 20, 2021 - The next method carries the name toLocaleDateString() and it returns a string with a language sensitive representation of the date portion of this date. It can utilize “locales” and “options” just like the previous method.
Day.js
day.js.org › docs › en › display › format
Format · Day.js
Because preferred formatting differs based on locale, there are a few localized format tokens that can be used based on its locale.
CopyProgramming
copyprogramming.com › howto › javascript-tolocaledatestring-locales-list
List of locales for Javascript's toLocaleDateString - Javascript array
March 23, 2023 - Date.prototype.toLocaleString(), Using toLocaleString () In basic use without specifying a locale, a formatted string in the default locale and with default options is returned. const date = new Date(Date.UTC(2012, 11, 12, 3, 0, 0)); // toLocaleString () without arguments depends on the // implementation, the default locale, and the default time zone … · new Date("1983-March-25").toLocaleDateString('fr-CA', { year: 'numeric', month: '2-digit', day: '2-digit' }) '03/25/1983'
Codegrepper
codegrepper.com › code-examples › javascript › tolocaledatestring+locales+list
tolocaledatestring locales list Code Example
May 18, 2020 - const handleDateChange = (args: SchedulerDateChangeEvent) => { setEventDate(args.value.toLocaleDateString()); };