system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How did countries of the world come about deciding on a universal measurement for time?

I know there is a slight when considering “military” time, but every one agrees that there are 24 hrs in a day. How did we all come to agreement on this fact?
gpt
Europeans used it and conquered the rest of the world and converted everyone else.  Formally, of course there have been international standard organizations that codified everything eventually, but those came long after the practicalness of European mass expansion across the globe spreading their time systems, calendars, and much more to every corner of the earth.

If China conquered the world instead, we would be using their system, which is different.

Our current time system is a descendant of ancient Egyptian and Babylonian time systems which was changed and altered in various  cultures to get to what we have now.