Mostly Harmless (1992)

The fifth Hitchhiker's Guide book by Douglas Adams. It's easy to get disheartened when your planet has been blown up and the woman you love has vanished due to a misunderstanding about space/time. Instead, Arthur Dent makes the terrible mistake of starting to enjoy life a bit, and immediately all hell breaks loose. (Goodreads)

Watches

Arthur Dent's moonphase watch: A gift from his stepfather, the mechanical moonphase keeps ticking through years of being stranded on a backwater planet.

Source text: Exact wording has not yet been verified from an accessible copy; an edition-level passage is still needed.