The brain in this clock is PIC16F84A,The time will be displayed when the 'show' pushbutton is pressed. The digits of the time are displayed in BCD on the four LEDs. Tens of hours is displayed followed by hours, tens of minutes and then minutes.
Step 1: Parts
2.Crystal 32.768khz(you may find in ordinary clocks)
3.Four leds any color
4. Resistors 4x270 ohm
5. Ceramic cap 2x33 Pf
6. Push Buttons 3 peaces
Step 2: Programming and Wireing
The schematic and wiring you can see here they are very simple to understand.
Step 3: Finish Clock
Also I have upload a gif image too see how can you make too look the clock.
Here is my links: