I was forced to train 阿脾 sleep early. My first bun bun was no good - fired after 3 days and my husband works on shift. Every night after dinner, I'll take him inside the room and switch off all the light. Let him drinks milk, sing songs and forced him to sleep, otherwise I cannot sleep. Therefore, we always sleep very well from 9:00pm to 3:00am at the beginning.
Sometimes he cannot sleep after drinking the milk but he'll still stay on bed as the room is dark and I was i.e. nobody plays with him.