+++ This bug was initially created as a clone of Bug #1370859 +++ The date picker element shows the date as mm / dd / yyyy even when the system locale order is dd / mm / yyyy.

The picker follows app's locale, not system locale. See bug 1366134 for details on when we look into OS regional preferences for date patterns.

Hmmm. Bug 1366134 says "we look into regional locale selected by the user and if it matches the language portion" and "That means that if the user has Windows in "en-AU" and Firefox in "en-US" we recognize that both are in English, and use the Windows date pattern." However, I see this bug even with LC_TIME="en_NZ.UTF-8", so this is a separate issue. % locale LANG=en_NZ.UTF-8 LC_CTYPE="en_NZ.UTF-8" LC_NUMERIC="en_NZ.UTF-8" LC_TIME="en_NZ.UTF-8" LC_COLLATE=C LC_MONETARY="en_NZ.UTF-8" LC_MESSAGES=C LC_PAPER="en_NZ.UTF-8" LC_NAME="en_NZ.UTF-8" LC_ADDRESS="en_NZ.UTF-8" LC_TELEPHONE="en_NZ.UTF-8" LC_MEASUREMENT="en_NZ.UTF-8" LC_IDENTIFICATION="en_NZ.UTF-8" LC_ALL=

:karlt - What is your OS?

I'm seeing this on Gentoo Linux. I see the same behavior with LC_ALL=en_AU.UTF-8 or LC_ALL=en_GB.UTF-8.

Thanks! That's very helpful! So, basically this bug depends on bug 1337069. We currently have fairly basic OS language detection in Unix/Linux. The quote you referenced in comment 3 is for Windows. We should do the same for Linux/Unix. I'll keep it open, but expect the progress to be made exclusively in bug 1337069. Workaround is of course to use the Firefox in en-GB instead or en-US until we fix it properly in bug 1337069.

(In reply to Zibi Braniecki [:gandalf][:zibi] from comment #6) > Workaround is of course to use the Firefox in en-GB instead or > en-US [...] I don't know exactly what that means. I tried general.useragent.locale;en-GB but that had no effect. https://addons.mozilla.org/en-US/firefox/language-tools/ references https://addons.mozilla.org/en-US/firefox/addon/english-gb-language-pack/ but that says "This add-on is not compatible with your version of Firefox."

Hi Karl, you need to download en-GB Firefox - https://www.mozilla.org/pl/firefox/nightly/all/ or download en-GB langpack. Anyway, I landed two patches today and yesterday that should fix how we pick date/time based on the POSIX env values. It should automatically fix your case - as in, your date time should now follow en_NZ on en-US Firefox. Can you please verify it against latest nightly?

dd / mm / yyyy as expected now. Thank you!