I created this clock from three ammeters. One tells the hour, one tells minutes, and one tells seconds. There are several ways you can make the clock work: either a specifically designed PIC controller with other electrical components or a Real Time Clock chip and an Arduino Nano circuit board. I am happy to share Arduino code if you would like it to make your clock work. Or you can do what I did and have fun learning Arduino as you build the clock.
There are three holes on the back of the clock box. This was originally intended to allow you to change the time when the clock was going to be controlled by the PIC controller available from http://alan-parekh.com/projects/multimeter-clock-simpson-260/ (the finished clock was actually much simpler than what you can do here.) Feel free to ask questions and I will try to answer when I can. This was a very satisfying project to complete!
Video of the clock in action: http://youtu.be/PNT_aoCKn48