My baby isn't a baby anymore

When does it hit you that your child isn't a baby anymore?

We had our moment a few days ago. It was going to be a cool day so I dress her up in a long sleeved shirt, jeans and her new big girl shoes. (hard soled shoes) I look down and see this 

and it made me realize that she isn't a baby anymore. She is a little girl! Make time slow down! When people say that time flies when you have children, they were not kidding.

When did you have this realization with your children?