Have you ever noticed that a baby who is put to bed at the same time every night, will get very sleepy and start yawning when it nears it's bedtime? It's true......if you make an effort to make sure your baby is in bed at a certain time every night, it's body automatically gives it the urge to go to sleep. A good time frame for any child, will help the child conform to certain schedules and adhere to them.
Babies, and children who are allowed to stay up, late do not conform to certain schedules and rules. Therefore they will be unruly and not want to corporate when told it's time for bed. I have seen young children who have been allowed to wander around late at night, and this only causes them to feel the need to act up.
A nice quiet room with the lights low or completely out, is the best way for a child to sleep and rest well. If you feel the need for some sort of light in the child's room, then use one of the small night lights that you can find a at local department store. The light isn't so bright that it will keep the child awake.