An anecdotal aside: Many years ago, in the courtyard of an ancient monastery in Greece (I can't remember where), I was shown a Byzantine sundial with the hours, of course, written as a succession of Greek letters. An old monk pointed out to me that the hours from 11 AM to 2 PM were Z, H, Θ, and I, which spelled ζῆθι (ΖΗΘΙ in caps), meaning "live!" an alternative to the ancient imperative ζῆ. He meant that those were the hours that belonged to you, when you could relax from work, eat, and perhaps have a bit of a nap.
P.S. Thanks, nickel, for the polytonic! It works slick!