Sundial: Living Astro Clock

Connect I/O

About this app

Sundial turns your screen into a beautiful astronomical clock. It uses your location to calculate where the sun actually is in the sky, then casts shadows exactly the way a real sundial would: in the correct direction, at the correct length, and with the correct colour.

SET IT AS YOUR SCREENSAVER
On Android TV and Google TV, Sundial registers as a system screensaver. Go to Settings > Device Preferences > Screen saver, select Sundial, and your TV will display a beautiful, ever-changing clock whenever it goes idle. It also works as a screensaver on Android phones, tablets, and Chromebooks.

REAL SOLAR POSITION, NOT AN APPROXIMATION
Sundial computes the sun’s azimuth and altitude for your exact coordinates using the NOAA/Meeus astronomical algorithm. It’s the same math used by solar tracking systems. Shadows point in the astronomically correct direction for your location, date, and time of day.

SHADOWS THAT BEHAVE LIKE A REAL SUNDIAL
These are not standard drop shadows. The shadow is cast opposite the sun, just like a gnomon on a sundial. When the sun is low on the horizon, shadows stretch long and warm. At midday, they shorten and cool. Soft, multi-layered penumbra edges give them a graduated, natural falloff, not a hard cutout.

WORKS WITHOUT LOCATION TOO
If you prefer not to grant location access, Sundial falls back to a time-based arc that still produces beautiful shadow and colour transitions throughout the day.

FEATURES
• System screensaver (DreamService) on all Android devices
• Location-aware solar tracking with NOAA/Meeus algorithm
• Sundial-accurate shadow direction and length
• Altitude-driven shadow colour temperature
• Smooth day/night palette blending
• Volumetric highlights and ambient occlusion on the numeral
• Minute indicator orbiting the hour
• Time simulation slider to preview 24 hours of changes
• Runs on Android TV, Google TV, phones, tablets, and Chromebooks

What’s new

- Available as a Screensaver option on Android & Google TV