Pokémon Black and White Versions/Features/Seasons

Much like Generation II introduced a system of time, Generation V features a system of seasons. Seasons change every month, thus completing three cycles per year. With it comes aesthetic changes in the region, as well as some changes with the Pokémon found in the wild. It also reflects real life in affecting the time each part of the day is; for example, in winter, night is from 19:00 to 6:59, but in summer it is from 21:00 to 3:59. Additionally, and its evolution  change forms every season. Some areas can only be accessed in certain seasons.