One more clock...

There are too many computer boxes where I work, we keep them just in case we need to send them back to get them fixed. Let's face the reality, most of the time they are out of warranty when they decide to die... Then, I took one of them.

Easy to do:

You just need a mechanism that you can get from any old clock, or you can buy it online on a website like this one, it's even cheaper to buy a cheap clock from Ikea or a dollar store and get the mechanism out of it.
You just have to make a hole with a pencil in the box, that's it. It's just an expensive clock if you have to buy the laptop...