You can go to the clock-set screen. Press the B (middle) button when no icons are active. The clock screen will appear. Press and keep holding the C (right) button, then press the A (left) button. Now the date should start blinking. This is the clock-set screen. Your Tamagotchi is paused (not growing) while you're at the clock-set screen. Details about the button functions within the clock-set screen can be found on your instruction sheet.