Your child is growing up and so is his thought process. He will now start to understand a lot of things intellectually. Along with other things, you will start noticing that your child is now developing a clear sense of time. He will now start to identify whether it is day or night.
What you need to know
Your child may not fully understand the concept of time but will start associating it with things that he does everyday in the same order. When you ask him to get up, have a bath, have breakfast and get ready for school, he knows that it is morning. In the same way when you ask him to come for dinner, he knows it is night time. When he has milk and goes to play he knows that it is evening. He also starts understanding that tomorrow means the next day and also after night, morning will dawn.
Try sticking to daily routines to strengthen these concepts. Routines will give him a sense of security and will help him develop self-discipline. You don’t have to be too strict with establishing a time frame for your kid but set up a routine that works in your child’s interest.