We build every computer with a tiny electronic watch inside of them that can keep time. It works the same way as electronic watches do. It’s not perfectly accurate, but it works very, very well on its own, and then if you really need to you can also use the internet to synch it up with external references.
The tech used for electronic timekeeping is called the [quartz crystal oscillator](https://en.wikipedia.org/wiki/Crystal_oscillator). Basically, it works because quartz crystals change their shape when electric currents are applied to them. If you make the amount of electric current applied to the quartz crystal dependent on the crystal’s shape, then you can make a circuit that oscillates back and forth in a really-regular way, and then count those oscillations to do timekeeping.
Latest Answers