A girl in one of my classes looked up at her teacher and asked, "But my birthday is in two months and how do I even know if I'm growing or not?! Is it in my sleep, or right now?"
I remember that anxiety well. There is your deadline, right there waiting for you to be one year older and there is nothing you can do about it. You have no idea how to help yourself grow. The ridiculous grown-up answer is always, 'eat your carrots', or some such nonsense, but you know they have to say that because they are grown ups. I remember that worry of, what happens if one year goes by and you haven't grown? How do you know if your getting older? What if just your body grows and not your mind?
I wanted to hug the little one who asked. There are so many deadlines awaiting her I want to tell her not to worry about this one. But then, if she is like me, she would probably worry about all those unknown deadlines off in the future.
So my dear, there is nothing you can do. You just have to sit back, enjoy childhood, and let the years go by.