system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How did my 1980's watch maintain more accurate time than my digital clock from today?

When I was younger, I would set my watch to the shortwave time broadcasting station. The drift over months seemed minuscule. Now, I have digital clocks that seem to shift minutes in months. Other smart watches I use seem to loose seconds in a week, if not synchronized. Why are the new clocks much less accurate?
gpt
The watch was *meant* to be accurate and was made with higher-quality materials, especially by the standards of the time... not only “better” ones but ones more suitable for keeping accurate time.

Many electronics have ring or relaxation oscillator circuits— things that create a rhythmic on/off signal. These are entirely electronic, using the same type of parts already used to supply power, light up different segments of the display, etc. They’re also used to tune in radio stations and regulate the speed of digital circuitry, so they’re cheap or *already included* inside a clock radio type device.

But they’re not too accurate. A nice watch likely uses a quartz crystal. This is like a tiny “tuning fork”, it actually has vibrations going on in it. And it’s very good at keeping time accurately. 

Since this is the whole point of a good watch, and there isn’t other circuitry already there for other purposes, it seems like the obvious choice for timekeeping needs. But in the bedside clock where it has an alarm, maybe radio reception, powers a digital display, etc... the temptation to cheap out or repurpose existing circuits for timekeeping purposes would be stronger.