The moon starts the cycle as the days unfold
With fire begins Tuesday's birth.
Wednesday's waters, so stagnant and cold
They eat Thursday's trees 'till they're covered in mold
And Friday is covered in glitter and gold
While Saturday puts them to earth.
Then Sunday arrives as the week's realised,
And lights the way to its rebirth.
Had trouble remembering which day was which in Japanese, so I wrote this as a backup to my memory.
Every day in Japanese has its own element in it, Monday = moon, Tuesday = fire, etc.