The two versions of the Nintendo DS title will feature different locations, creatures, and seasons. Unlike other games in the series, the two versions the latest Pokémon entry will feature different locations. According to Nintendo, Pokémon Black features "a unique metropolitan area called Black City," while Pokémon White will have Poké Trainers explore "a lush, green area named White Forest."
Both versions also include seasonal changes. Select Pokémon will be easier to come across during certain times of year and areas within the game will be become blocked or accessible based on the game world's season. Both Black and White versions launched in Japan in mid-September 2010.
Gotta say, I really, really hate games that require you to wait 3 months to get to something.
Change the system date?