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?
Beyond maybe needing some sort of space calendar if we ever actually get off this rock in a way that matters, why not? An extra digit isnt all that big of a hassle.
If we’re no longer on earth, days and years will be based on whatever orbit we’re following. So I guess the counter would start from zero.