Kenko, Tsurezure Gusa
212 (tr. G.B. Sansom):
The autumn moon is of loveliness without end. Nobody is more pitiable than a man who cannot see the difference, and thinks the moon is the same at all time.Online Etymology Dictionary
s.v. moonlight (v.)
"hold a second job, especially at night," 1957 (implied in moonlighting), from moonlighter (1954), from the notion of working by the light of the moon.Chicago Sunday Tribune
(July 18, 1957):
There is a new word in the vocabulary of labor statistics and employment — moonlighting. The moonlighter, unlike the moonshiner, is not conducting some illicit trade under the faint lunar beams. He is a respectable citizen, a thrifty citizen bent on achieving the better things of life — a guy who holds two jobs.
I wouldn't call myself a respectable citizen, but I'll be moonlighting for the next few weeks or possibly months, and so I won't have the leisure to blog every day during that time.