Answer:
If you break me, I'll not stop working. If you can touch me, my work is done. What am I?
I'm sometimes white but most often I'm black. I take you there but never bring you back.
I am whole but incomplete. I have no eyes yet I see. You can see and see right through me. My largest part is one fourth of what I once was.
I am all around, yet to me you are half blind. Sunlight makes me invisible and difficult to find. What am I?
I spend the day at the window go to the table for meals and hide at night.
What is always coming but never arrives?