Instructions
Load the Nintendo Wii to the main menu.
Point your Wii Remote at the wrench icon in the lower left-hand corner of the screen. Press "A."
Direct your Remote to "Calendar," the second option on the first page, and press "A."
Motion your Remote towards the arrows surrounding the part of the date you wish to alter. Press "A" to change that part of the date. For example, if it is September, pick the down arrow four times to change the month to December. To qualify as winter, you must set the date between December 21 and March 21.
Point your Remote at "Confirm" and press "A" to save your settings.
Load your saved game in "Animal Crossing." With the date changed, you will see snow begin to fall in the world.