This is valid (if somewhat obscure) notation for decimal dates in particular, see e.g. https://en.wikipedia.org/wiki/Long_Now_Foundation
> the foundation uses 5-digit dates to address the Year 10,000 problem
That just sets you up for the year 100,000 problem. The objectively better idea is to just parse years as regular integers, something that I'm confident people will figure out in the remaining 8 millennia until the problem actually hits.
The Long Now Foundation uses five-digit dates, the extra zero is to solve the deca-millennium bug which will come into effect in about 8,000 years.
but the truth is more subtle, love it or hate it the five digits are part of a campaign to encourage people to think about humans in timescales a tad longer than a few decades at most.
I think the campaign does opposite of what it says. Using 5 digits limits your dates to dates to a maximum of year 99999. While not giving a fuck, using the digits needed to represent a year, works for all years. No one is clamping their years to 4 digits when they say '2024', they are just using the necessary digits needed for that year
given the choice between trying to demonstrate intelligence, and trying to demonstrate viciousness, i prefer the former. i guess your preference is different
(As of A.D. MMXXIV)
Five digits don't even make sense in practical anthropic terms, since we're obviously headed for a shitload of trouble long before the hundreds digit next wraps.