Square Enix has revealed the launch date for Final Fantasy XIII through an online add campaign that was initially only intended to serve as a teaser.

The publisher is set to put out the Japanese role playing game on December 17 but this date is only for the Japanese market, where the game can be picked up only for the PlayStation 3 home gaming console from Sony. The dates for the rest of the world and for the Xbox 360 version are not being talked about at the moment.

Square Enix was careless enough to include the word “before” on the URL for the teaser site that was intended to popularize an event set to take place in Tokyo, where presumably the release date would be revealed. Intrepid fans simply changed that word to after and they got to this site, which showed December 17 as being the date when Final Fantasy XIII could be found on store shelves. Despite the mishap, Square Enix has not confirmed the date so far, although it is set to do so in less than one day.

Western fans of the long running JRPG series might wonder why the game is arriving early and on the PS3 only in Japan while the rest of the world has to wait an unconfirmed period.

It all has to do with the announcement at this year's E3 that the game was no longer exclusive to the Sony platform but would be also arriving on the Xbox 360. Microsoft's move meant that Square Enix needs to take some time to port the game to the Microsoft platform and to decide how to deliver the content on another support than the Blu-ray.

The game is expected to arrive in the West at the same time on both gaming devices with full localized voices. The date will probably be set a month before June 2010.