Acronycal

Meaning: happening at sunset; an astronomical term referring to stars which rise at sunset.

Usefulness: 1 (Mainly in poetic senses, although it could also be used to describe one's martini, depending on how early or late sunset is.)

Logofascination: 1 (Besides my being mildly infatuated with star-words at the moment, it's worth pointing out that the slightly odd-looking spelling is due to its etymological parentage. It's not from chronos, as in time, but from acro- and nycti-, or night-rising. Its opposite - rising at dawn - is cosmical.)

In the wild: in a lovely list of time-related words over at Gleeful.

Degrees: 2

Connections: acronycal - sunset

Which is used in: G&P, Third Book, XXVI: How Panurge consulteth with Friar John of the Funnels. Back on the subject of Panurge's potential marriage, Friar John tells him to get on with it:

As I say marry, so do I understand that thou shouldst fall to work as speedily as may be; yea, my meaning is that thou oughtest to be so quick and forward therein, as on this same very day, before sunset, to cause proclaim thy banns of matrimony, and make provision of bedsteads. By the blood of a hog's-pudding, till when wouldst thou delay the acting of a husband's part? Dost thou not know, and is it not daily told unto thee, that the end of the world approacheth? 

 "Make provision of bedsteads" will be my advice to newly-engaged couples henceforth.