Just a photo of a sundial from the deCordova Sculpture Park. The interesting thing about the Latin is that, assuming revertit is a present tense, it has to be from reverto instead of revertor. Students could be challenged to compose other suitable texts for a sundial. Or to find other Latin examples to share.
How sundials (and other ancient time-telling tools, like water-clocks) work are also a nice scientific/cultural topic.