Answer:
The more you look at me The less you see.
What is seen in the middle of March and April that cannot be seen at the beginning or end of either month?
I turn around once. What is out will not get in. I turn around again. What is in will not get out.
You get embarrassed when you stand on me when everybody is watching. Women don't like to talk about the number they see on me. Everyone stands on me when nobody is around
In your fire you hear me scream creaking and whining yet I am dead before you lay me in your hearth.
No matter how little or how much you use me, you change me every month.