The joke of a wrist-worn sundial is probably as old as the sundial. But this has not deterred MaxCo. - we laugh in the face of old jokes.

The MaxCo. Wrist Sundial has a case hewn from living granite, which conceals an intricate and sophisticated mechanism. Engraved on the face are the usual twelve Roman numerals.

The periphery of the dial contains light sensors which can ascertain the current direction of the sun, relative to the wearer's wrist. The act of raising one's forearm and rotating the wrist slightly towards the face, is detected by a set of motion sensors, triggering two events. First, a miniature bronze gnomon springs up out of the face of the watch. Second, the entire face of the watch rotates to bring the correct point under the gnomon's shadow, indicating the correct time to within five or ten minutes.

In the event that the sun is not visible, the watch relies instead on the strongest artificial light source. In the event that there are no artificial light sources, it doesn't matter because you won't be able to see the watch.
-- MaxwellBuchanan, Aug 01 2015

Fred Flintstones version https://www.google....-w&biw=1000&bih=644
This is the prior art. [popbottle, Aug 01 2015]

<does old-style facepalm [metacarpals to forehead]>
<gets old-fashioned poke in the eye>
-- lurch, Aug 01 2015


I'll wait for the model with the lighted dial for night time.
-- cudgel, Aug 01 2015


This would of course be useless in wales, as apart from the fact that artificial sources of illumination are unknown there, the area is reknowned as The Place Upon Which The Sun Does Not Shine. And that's not just due to the ever-present lowering rainclouds, either.

Getting it to display a time and date 5000 years before the present will also be tricky.
-- 8th of 7, Aug 01 2015


If the sky was cloudy, then the light sensors could use the polarisation of the diffuse light from the sky to orient the device. I would also like a second outer bezel showing civil time, i.e. which rotated independently to indicate equation-of-time and time-zone and daylight-saving-time offset.
-- pocmloc, Aug 02 2015



random, halfbakery