Answer:
You find me behind the stars; or in a sixth seventh or third. It takes something round a computer and me to make pie. I am bigger than anything you can think of.
I have a head and a tail but my eyes can never see my tail.
I sit in a corner while travelling around the world.
Every dawn begins with me. At dusk I'll be the first you see and daybreak couldn't come without. What midday centers all about. Daises grow from me I'm told. And when I come I end all code but in the sun I won't be found. Yet still each day I'll be around.
I save lives on the ground and in the air. What am I?
It flows out of the soil, It burns you if it boils, And holds us in its coils, More valuable than gold, As black as it is old.