By default, symfony2 can control the extension "en", but to get a different language you need to install the extension php-intl .
The easiest option is to install it with the composer as it provides you with a global variable ... etc.
All of this is explained here by symfony / components / intl .
To install the extension for the composer symfony / components / using_components .
So, after that you should do:
composer require symfony/intl
- EDIT
Ok, sorry, I just checked the solution, and the fact is that if you use the symfony component, you only have access to "en". I have the same problem as you, my php5-intl extension was installed and activated, but the error persisted. For me it was that I continue to write use Symfony\Component\Intl\DateFormatter\IntlDateFormatter; at the top of my file instead of using the main php5 extension.
Thomas Leduc
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