Yes, it is normal for Tamagotchi's to sleep 3+ hours.
Though, they should not sleep this much during the
day. If they are, your children have not set the time correctly.
To change the time:
> Press the middle button, it will show the time which has been set.
>
hold the left side button (button a) and the middle button (button
> The date will blink first, if its correct, simply press button b to continue on to the time.
> Use button a, to change the time for hours, and minutes.
> Once the time has been set properly, press button b, to set.
> Press button b again to return to the normal screen of your Tamagotchi.
I hope that is clear enough.
//Haze