Reinventing obsolete devices seems quite popular now, enter the “Bulbdial” concept –

I think we can all agree that sundials pretty much suck. They only have an hour hand, they don’t work at night or indoors, their accuracy changes with the seasons, and if you happen to live in the Southern hemisphere they run backwards. And yet, we all would love to be able to tell the time by looking at shadows, right?
The Bulbdial Clock has no hands — just one pole in the center of the clock, and three light sources of varying heights which revolve around the pole casting shadows. In the model illustrated above, the light sources are each attached to a ring which rotates around the pole. The innermost ring rotates once per minute, casting a “second hand” shadow. The middle ring rotates once per hour, and casts the “minute hand” shadow. And the outer ring rotates once every 12 hours, casting the “little hand” shadow.

It appears this design would necessitate indoor usage. Seems quite do-able with microccontroller + LEDs. – Bulbdial on Ironic Sans

Make 1171
DIY Sundial for your garden

Sundial for the 22nd Century

Life Clock2
Life Clock