To modify a language's locale settings, follow these steps:

1. To check the installed languages and their configurations, select the Settings | Translations | Languages menu option. Clicking on one of the installed languages will open a form with the corresponding settings:
   
2. Edit the language settings. To change the date to the ISO format, change Date Format to %Y-%m-%d, and to change the number format to use a comma as a decimal separator, modify the Decimal Separator and Thousands Separator fields accordingly.