Course, medium, and fine; marking the passage of time; I wear, polish, and grind.

I'm known for my secrets, though I might not exist, The wealthy and mighty are often on my list. My title suggests light, but darkness I claim. What am I, a subject of rumor and fame?

Though hazy I may be, the weather isn’t me. Through story I may be told, and I am dear to the old.

With fire and hammer, I shape the unyielding, turning metal to blade and horseshoe gleaming. Though I don no armor, I forge the knight's shield, crafting tools for battles in every field.

I have no mouth, yet I tell the truth. I can be hidden, but never lost. I am weightless, yet I carry the past. Those who seek me shape the future at last. What am I?