Box Clock Screensaver 

Box Clock Screensaver will put an animated mechanical clock on your desktop.

You can set this screensaver to start after your computer has been idle for a while. It will display a square mechanical clock showing you the real time, including a second indicator. This program will also show an abstract animation in the background, to improve the clock´s appearance.

The screen savers are programs that avoid a problem that affected the monitors in the past. When the same image was displayed for long periods, the phosphor coating in the inner zone of the monitor where the image was shown darkened and showed a ghost image on the screen.

Through the Windows´ Screen Saver Options you can choose how much time will the computer wait until launching the screen saver, and if you want it to display the logon screen on resume. The "Settings" button will let you access the program´s options, where you can choose the quality that you want to use when showing the screen saver (between six possible values), and whether you want it to loop.