Hi, none as that is all controlled by your OS and you should check a forum of your flavour of Linux for help/info.

As to the Language pack changing things, please see the Developers site for support/info.

Please let us know if this solved your issue or if need further assistance.

What if you switch from the en-US (U.S. English) build to the en-GB (British English) build? I think that might switch the dates and times to the European style.

I don't know the best way to try that since Linux users have various installation options and configuration issues. If you are installing manually, you can get en-GB from this page:

https://www.mozilla.org/en-GB/firefox/all/

And see: Install Firefox on Linux

Pkshadow said

As to the Language pack changing things, please see the Developers site for support/info.

The Language Pack being those on https://addons.mozilla.org/firefox/language-tools/ and not something else.

thanks for your replies!

i have tried and installed the English (GB) Language Pack and deactivated all others. i have attached a screenshot of this screen.. and also a screenshot of the library window - here you can see that the date format is the MM/DD/YYYY... then i only enabled the german language pack and reopend the Library. again of both screens i have attached a screenshot. in the library window the changes are instantly visible (after reopen it) i also tested the javascript behavior in the developer console: event = new Date(); console.log(event.toLocaleString()); if only the English (GB) Language Pack is active i get " 4/25/2018, 5:47:23 PM" if i activate the German Pack (the English one is also active) i get " 25.4.2018, 17:48:11"

so it seems to me that the system settings are not controlling this directly - its more the language packs.. but somehow if both packs are active German wins - this could come from some system setting...

as Firefox itself is installed via the package management tool (for me that is apt) i don't want to mess with this.... but i searched there and both the english and german language packages are installed there too... (there is no GB one in the available packages - its only on with 'English')

if there is a better place to discuss this pleas let me know.

The attached troubleshooting information shows:

osPrefs: regionalPrefsLocales:["de-DE"]; systemLocales:["de-DE"]; 
localeService: available:["en-GB","en-US"]; requested:["de-DE","en-US"]; regionalPrefs:["en-US","en-GB"]; supported:["en-US","en-GB"]; defaultLocale:"en-US";

See also this pref:

• intl.regional_prefs.use_os_locales

Hi cor-el,

i have made a some test: i changed only the 'region settings' to something unique: 'en_DK' at the OS-Level.

• logout and login (so these settings are really used by the system)
• start Firefox -
• get the same information from the about:support page

"intl": {

   "localeService": {
     "requested": [
       "en-DK",
       "en-US"
     ],
     "available": [
       "en-GB",
       "en-US"
     ],
     "supported": [
       "en-US",
       "en-GB"
     ],
     "regionalPrefs": [
       "en-US",
       "en-GB"
     ],
     "defaultLocale": "en-US"
   },
   "osPrefs": {
     "systemLocales": [
       "en-DK"
     ],
     "regionalPrefsLocales": [
       "de-DE"
     ]
   }

so seems it is really the system that brings this in... i tried and set the system settings another way - this time splitting the 'region' and the formats (like in the second screenshot i attached) this gives

"intl": {
   "localeService": {
     "requested": [
       "en-GB",
       "en-US"
     ],
     "available": [
       "en-GB",
       "en-US"
     ],
     "supported": [
       "en-GB",
       "en-US"
     ],
     "regionalPrefs": [
       "en-GB",
       "en-US"
     ],
     "defaultLocale": "en-US"
   },
   "osPrefs": {
     "systemLocales": [
       "en-GB"
     ],
     "regionalPrefsLocales": [
       "de-DE"
     ]
   }
 },

so its better than before - i now have 24Hours format :-)

then i research on regarding your mentioned config

and found a similar question at mozillaZine this lead me to a [bug report https://bugzilla.mozilla.org/show_bug.cgi?id=1379910] where this is discussed.

so i changed my system configuration back to de_DE as Region settings without detailed settings. than changed the preference intl.regional_prefs.use_os_locales: true to true and restarted the system.

this leads to "intl": {

   "localeService": {
     "requested": [
       "de-DE",
       "en-US"
     ],
     "available": [
       "en-GB",
       "de",
       "en-US"
     ],
     "supported": [
       "de",
       "en-US",
       "en-GB"
     ],
     "regionalPrefs": [
       "de-DE"
     ],
     "defaultLocale": "en-US"
   },
   "osPrefs": {
     "systemLocales": [
       "de-DE"
     ],
     "regionalPrefsLocales": [
       "de-DE"
     ]
   }
 },

this time the format was fine but the user interface language switched back to German too :-(

next i tried again to split - set region to United Kingdom and all Detailed Settings to German. after an restart i got "intl": {

   "localeService": {
     "requested": [
       "en-GB",
       "en-US"
     ],
     "available": [
       "en-GB",
       "de",
       "en-US"
     ],
     "supported": [
       "en-GB",
       "en-US"
     ],
     "regionalPrefs": [
       "de-DE"
     ],
     "defaultLocale": "en-US"
   },
   "osPrefs": {
     "systemLocales": [
       "en-GB"
     ],
     "regionalPrefsLocales": [
       "de-DE"
     ]
   }
 },

and this time it worked!!

thanks for pointing me in the right direction to fix this :-)