system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How did the entire planet manage to agree to live on the same 24 hour clock?

I feel like maybe cause every civilization used the sun as a time keeper? I just want to know for sure.
gpt
People (France) tried to introduce metric time and metric days, but it didn't last.

60 seconds in a minute and 60 minutes in an hour started with one of the oldest civilization - Sumer. 

Later, ancient Egyptians divided the day into two 12hour parts.