My wife observed last night that our young cats are very active at twilight. No surprise there, said I. Neither diurnal nor nocturnal in their hunting habits, housecats are a crepuscular species of critter. The word derives from the Latin crepuscula, twilight. But there is morning twilight and evening twilight. And so critters crepuscular are either matinal or vespertine or both. Matins are prayers said in the morning while vespers are prayers said in the evening. Cats, however, prey rather than pray. When not on the prowl or in play they sleep, having been made in the image and likeness of Sloth.
There is also an interesting etymological connection between Hesperus (Hesperos), the Evening Star, and vespers. Hesperos/Hesperus became the Latin Vesperus. Eosphoros/Phosphoros became the Latin Luciferus, Lucifer, light-bearer, from L. lux, lucis, light. Interesting that the Bearer of Light in his later career became the Prince of Darkness.
Eosphoros and Hesperos in their later careers went from being gods to being mere Fregean senses, mere modes of representation, Darstellungsweisen, and conduits of reference.
Here a cool cat name of Thelonious Sphere Monk bangs out "Crepuscule with Nellie." Was he on the prowl with her, or just hanging out in the gloaming?