Learn how to create and use sundials and astrolabes

Shadows is a free software developped by François Blateyron and aimed at designing sundials and astrolabes. It can be used by everyone without any required technical skills. Shadows will calculate, draw and print the drawing according to the user's preferences. Shadows is used by thousands of users around the world. Discover the world of sundials on this web site through educational pages and photo galleries.

Shadows software

The Shadows software is acclaimed around the world for its ease of use and its power. Create your first sundial customized for your place.

Discover Shadows »


Learn how to read time on a sundial; discover the different types of sundials and browse through the gallery of sundial photographs.

Discover sundials »


An astrolabe is a great astronomical calculator and at the same time a magnificient piece of craft art, usually seen in museums.

Discover astrolabes »

Shadows software

Shadows is a software package for calculating and drawing sundials and astrolabes. Its base version is free and can be downloaded in a couple of minutes. Shadows Expert and Shadows Pro bring powerful advanced and professional features. They require a paid license.


Discover sundials with a series of educational pages. Learn how to read time on a sundial and to use the equation of time to correct solar time. Watch photographs of sundials of France and other places.

Learn how to read time on a sundial »   Photographs of sundials »  


An astrolabe is an astronomical calculator in the shape of a disk in brass with mobile elements and engraved scales. Put your hands on various types of astrolabes and discover how to use them.

Understand how astrolabes work »   The planispheric astrolabe »  

Subscribe to our mailing list

* indicates required

Sundial - Cadran solaire - Sonnenuhr - Reloj de sol - Cuadrante solar - Meridiana - Orologio solare - Relógio de sol - Quadrante solar - Zonnewijzer - Zegar słoneczny - Sluneční hodiny - солнечные часы - слънчев часовник