system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If a civilization relied on the sun to tell time, what did they do on a very cloudy day?
gpt
Until the modern age(locomotive trains, and telegraphs), knowing precisely what time it was, was not very important. Only when communication and travel  between groups of people in different places became the norm, did accurate timekeeping matter.