There isn't a Pause function, but generally, if you leave a Tamagotchi at the clock-set screen, it's effectively paused. (However, you may want to experiment with that on your Tamagotchi-iD. Also, I'm not sure whether the backlight turns off at the clock-set screen. If it doesn't, expect a set of batteries to last about 2 days.) Otherwise, maybe try time-shifting (setting the clock so your Tamagotchi-iD sleeps while you're at school.)