Answer:
I am a span of time you can always see through I am also the timepiece with the most pieces. What am I?
Who makes it, has no need of it. Who buys it, has no use for it. Who uses it can neither see nor feel it. What is it?
What do you throw out to use and take in when you're done?
What flies around all day but never goes anywhere?
It's equally comfortable in an orchestra and a geometry textbook. What is it?
What is always coming but never arrives?