Answer:
A hole in a pole, though I fill a hole in white. I'm used more by the day, and less by the night.
Flat as a leaf, round as a ring. Has two eyes, can't see a thing.
I'm sometimes white and always wrong. I can break a heart and hurt the strong. I can build love or tear it down. I can make a smile or bring a frown.
Iron roof, glass walls, burns and burns and never falls.
What can you fold but not crease?
My days are numbered.