Long before there were digital watches, there was the sundial–a device that tells the time of day by the position of the sun in the sky. They're harder to read than our modern means of time telling, until now. Etsy shop Mojoptix has created a 3D-printed version of the sundial that displays the actual digits as it moves with the sun.
Aptly called the Digital Sundial, it's a plastic wand with a series of holes that are cut into it. To figure out the precise dot placement, Motoptix had to calculate the angle of the sun as it travels across the sky, which allows the device to "digitally" show the approximate time. It's an extremely impressive improvement on the sundial, but the product does have its limitations: it only displays times from 10AM to 4PM in 20-minute increments.
You can purchase your own Digital Sundial through Etsy, which comes as a kit that you assemble. Alternatively, you can download the design files and print the clock at home. If you're interested in how Motoptix created the ingenious product, watch him explain it the video, below.
The unassembled kit.