Weekly What? Week 6

Hello! Finals have been a real killer, but they are finally winding down (no pun intended). I thought up this riddle this evening and figured I would let you take a stab at it! It was not what I intended for this week’s “Weekly What?”, but it will do. Solve this riddle! Who is “You?”

Caught betwixt sunlight, starlight;
The beauty quietly awaits.
A glimmering, shimmering sight;
Always, too soon, you abate.

The end of one, another long turn.
Moonlight spins a tale.
Dreams drift hazily in nocturnes
As you, across empyreal, sail.

Once departed, Dawn of night,
Sleep sings, softly lulls.
Return on morning’s eventide:
You, most beautiful of all.