The goal is to train Julia when it's time to wake up in the morning. If she wakes up too early and the lite is still a moon, she has been told that she needs to go back to sleep or play quietly until the sun comes up. She's an early riser like her parents.
I think she caught on the first time we tried it. The first night we sat in front of it until it turned blue (big smile). When the light turned blue she exclaimed that it had the letter S all around it...not too bad considering that a Z looks a lot like a S. The next morning, right at the preset time, Stacey heard a faint "Momma" coming from her room. We think she woke up a few minutes before and waited until the sun came on...