Instructions
Turn on your DS with the "Sims 2" game inserted in your game slot. Select the "Settings" option on the DS main menu.
Select the "Clock" option in the settings menu.
Select the "Date" option in the clock menu. Press the "Up" and "Down" buttons on the screen to change the date to your liking.
Select the "Confirm" option once you have set the date. The DS will restart. Select the "Sims 2" icon in the DS main menu and you will begin playing the game with the changed date.