Local translations

How often is the database of translation updated?

Can you better explain your question? What translation are you talking about?

Of the ID editor.

If updating the translations requires some action by the maintainer, it’s possible that it is delayed by the current absence of a maintainer. (Quincy left the post, and there’s no successor for him yet. An interim solution was recently announced, though.)

Is there any way to update as soon as possible the greek database?
There are many new features that should be added to the greek menu!

Sorry man, not only Greek translations wait for the update. You can poke the developers of iD on GitHub.