I like sun clocks but the sun only seldom shows up in my office (in fact, never). That's why I build up an electronic version with LED lights. The heart is a ATmega8 controller with a quartz oscillator. Despite that I never soldered such a circuit before, the result is acceptable.
Some steps are documented with a camera. Enjoy.
The ISP is an ATeval board. Cheap but powerful and easy to use.
The clock is still running.