The letter E
I'm not known of my existence I'm not in the sky what am I
What is the beginning of eternity, The end of time and space, The beginning of every end, And the end of every race?
You have me today, Tomorrow you’ll have more; As your time passes, I’m not easy to store; I don’t take up space, But I’m only in one place; I am what you saw, But not what you see. What am I?