Waiting time for username availability

I want to know the waiting time to get a username that was changed by a person.

• Example:

the user already with the username "joao" changed his username to "joao1". How long will it take for the username "joao" to be available again for someone to use? This should have already been clarified by the usernames FAQ.

I'm using google translator to translate this into English, sorry for any misunderstanding in reading.