Why is date locale 'en-CA' returning M/d/yyyy instead of yyyy-MM-dd?

Question

I have JavaScript code which displays the current date in en-CA format.

date = new Date();
console.log(date.toLocaleDateString('en-CA'));

Previously the en-CA locale formatted dates as yyyy-MM-dd (2023-02-24). However, as of today these dates suddenly started displaying as M/d/yyyy (2/24/2023) without me making any changes to the code. I've reproduced this issue across two different computers running Chrome, Firefox, and Edge on Windows 10 & 11.

Why did the en-CA locale start formatting dates as M/d/yyyy instead of yyyy-MM-dd?

what browser are you targeting? its working in safari for me — Daniel A. White, Feb 24 '23 at 23:03
@DanielA.White I mention in the question I tested in Chrome, Firefox, and Edge. — Stevoisiak, Feb 24 '23 at 23:04
I tested in Firefox and Node, it behaves as expected. Then I tested in Chrome and it behaves as you described. — Slava Knyazev, Feb 24 '23 at 23:05
@SlavaKnyazev I get the wrong format ; `2/25/2023` on `Chrome`, `Firefox` — Mister Jojo, Feb 24 '23 at 23:09
Because data for various language formats is from the CLDR, which recently changed the format of en-ca from y-MM-dd to M/d/y. Do not use *toLocaleString* if you want reliable formatting. — RobG, Feb 25 '23 at 06:55

score 2 · Accepted Answer · edited Feb 28 '23 at 19:34

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Because a mistake in unicode CLDR component version 42 was rolled out into Chrome, Edge, Firefox and Node 19 in Feb 2023. It is currently expected to be reverted in version 43. Safari seems to have avoided it.

In the case of Chrome, they expect to correct this in the next release 111 whatever the CLDR release cycle is.

edited Feb 28 '23 at 19:34

Stevoisiak

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answered Feb 28 '23 at 17:26

Chris F Carroll

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I can confirm the date format for `en-CA` was reverted in Chrome 111. – Stevoisiak Mar 10 '23 at 21:31
in Android WebView still issue remains. Can anyone also check and confirm. I tried and still returning wrong format in android webview. Device chrome browser is updated to 111. – mitsena Mar 23 '23 at 18:00

Stevoisiak · Answer 2 · 2023-02-24T23:31:58.443

Apparently the en-CA format was changed in Chrome 110 and Firefox 110.

The exact format of .toLocaleDateString('en-CA') is not portable and will break in newer browsers! It recently changed from yyyy-MM-dd to M/d/yyyy in browsers with ICU 72 (Chrome 110 and Firefox 110 beta). Do not make assumptions about specific the specific formatting of locales. Use one of the answers based on .toISOString()

Anders Kaseorg

This is also noted in a GitHub Issue for Node v19.1.0.

Node >= v19.1.0 ships with a newer version of ICU (i18n library), that's why there's a difference.

There's no bug, it's working as expected.

bnoordhuis

score 0 · Answer 3 · answered Mar 17 '23 at 11:15

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In new 111 version of Chrome its rolled out Check it

But its more safety to use native date convert in necesary format

answered Mar 17 '23 at 11:15

Gregory Tomilin

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in Android WebView still issue remains. Can anyone also check and confirm. I tried and still returning wrong format in android webview. Device chrome browser is updated to 111. – mitsena Mar 23 '23 at 17:59

Why is date locale 'en-CA' returning M/d/yyyy instead of yyyy-MM-dd?

3 Answers3

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