It seems like it’d get increasingly impractical as the years go on to hundreds of thousands and millions of years to write them out that way, but then…I guess technically one may already do this with the preceding years, so future’s fair game for it?
I don’t see why not. 5 digits isn’t too bad, and the issue wouldn’t come up again for another 90,000 years after that. Besides, we’ll probably extinct ourselves through climate change, nuclear war, and/or AI long before then anyways.