My husband organized a sundial with seashells on the lawn where we live in tents.
You can see the dial where the hours are indicated by the number of seashells. Here in the middle stands a stick from which a shadow falls on the corresponding figure and shows the hour. It is clear that such a clock works only when the sun is shining.
Honestly, I don't know how he set this time, but it works for sure! We checked with a mobile phone. Once upon a time people did not need time after sunset because they went to sleep in the dark and got up with the sun.
Thank you for your visit!