How does a device like a phone or tablet accurately keep track of time?

Question

For context, let us consider something that would be disconnected from a network to prevent syncing with the internet.

In: Technology

Answer 1

A small quartz tuning fork is placed inside of the device. This fork, powered by electricity, creates a vibrating signal. This signal can then be literally counted, and if you know how many counts make a second then keeping time is trivial.