Aderation :

Saturnalian :

Bissextile :

Lunation :

Occiput :

Assign to a thing
Value in cha–ching.

Of revelry unchecked :
Eat, drink, sex .

Of a leap day fix
For annual hour + six .

Time of moonglow
Ere fall of shadow .

Succinctly said,
Astern of the head .