They do not go to sleep, in the night time. 

They do not wake up in the day time. Normaly their morning starts with afternoon. 

I do not know why and I do not understand. It is just a bad habit? They acquired this habit from childhood? Or all the young people, the next generation, do not go to sleep in the night and can not wake up on time in the morning? 

They do not go to sleep till 4am or even 5am. It bothers me a lot! It bothers me so much so I can not go to sleep either. I feel frustrated and upset and angery. They do not go to sleep in the night time then they feel sleepy and tired in the day time, the time they supposed to do something meaningful or useful or helpful. But they can not, even can not enjoy some fine time such as sighseeing when we ae out for vacations.

Do I spoil them? Should I just let it go, let them do whatever they want and whenever they want it? The most annoyin thing is I am not sure if I am spoiling them.

Sleeping, or not sleeping,  makes me confused, angary and upset. It ruins our family fine time, ruins our so called vacation time, ruins our moods, eventually our life itself.

What is going on, the world!