I’m sure you’re joking, but finding the position of the sun is (or was) important for navigation too. Vikings used to use crystals to locate the sun when it was cloudy

https://en.wikipedia.org/wiki/Sunstone_(medieval)

There is a willow grows aslant a brook, That shows his hoar leaves in the glassy stream. There with fantastic garlands did she come Of crow-flowers, nettles, daisies, and long purples That liberal shepherds give a grosser name, But our cold maids do dead men’s fingers call them

At least she didn’t pull a boner.