A nocturnal, also known as a star dial, is an analog computer used for telling the time using the relative positions of stars in the night sky.
- Pointer stars of Ursa Major
- Kochab of Ursa Minor
- Shedar of Cassiopeia
- Spot one of the reference stars and align the relevant constellation on the inner ring with the current date on the outer ring.
- Sight the North star (Polaris) trough the center hole
- With the handle pointing down, align the Pointer with the chosen reference star
- The Pointer now intersects the current time on the inner ring!
NB - The customizer app seems to return an error while rendering the more complex components (Inner and Outer Rings), I'm looking into this problem but for now I have uploaded STLs for the 'Spiral' style nocturnal, and you can still customize by downloading the OpenSCAD file.