AirPlay works- but can't log on to iTunes

Hi

When i turn ón my Apple TV3 - it says something like "Update date and time" The only Thing i Can do is to push menu to exit. I Can now use the atv3 for AirPlay from eg my iPhone or iPad but i Can not log ón to my iTunes acount from the atv3 - I dont Think the atv3 Can connect to the internet. All my other devices have no trouble connecting to the internet - i have used the atv3 without a cable and with a cable that makes no difference - has someone Got a god advice for me :-)