2019年12月21日(土) 17:06 Bo Persson via Std-Proposals <std-proposals@lists.isocpp.org>:

What is the use case for a wider range? The current civil calendar has
"only" been in use for about 500 years.

So what does it mean to have a date 100.000 years into the future? It
will surely be incorrect anyway becase of some political decisions made
before we get there (if we ever do...).

I think we should have consistent valid range.
Normally,  min() and max() function means valid range. However, system_clock::time_point::max() is invalid.
If you right, why valid range is not 500 years? What's the mean time_point::max(), min()?

I need how to know valid range.