system
Given the following post, respond as if you're commenting on Reddit:
human
Has there ever been an attempt to create a SI unit of time?

I know seconds, minutes, milliseconds, etc. are SI units now, but has there ever been an attempt to create one more like grams and liters? That is, grounded in some naturalistic value and scaled only by powers of ten?
gpt
The second is based on something physical - it's defined as "the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom".

It may seem somewhat arbitrary, because it isn't based on anything fundamental to the universe, but it's no more so than, for example, the kilogram - which is the mass of a cylinder of platinum and iridium held in a vault in Paris.  The meter is actually defined in terms of the second, and doesn't have it's own reference point.