system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do watches work?

I started learning more about watches and still can’t figure out how mechanical watches work? How does a watch know a “second” lasts an actual second?
gpt
The watch doesn't "know" anything. Basically a type of spring provides the energy that turns the gears. Special gears and latches regulate how far they turn. So we just choose gears of the right size with the right number of cogs so that it turns the right amount to correspond with seconds/minutes/hours.