Wouldn’t it be accurate for that as well? Unless we change to base 10 time units or something. Then we all have a lot of work to do.
But if it’s just about starting over from 0 being the AI apocalypse or something, I’m sure it’ll be more manageable, and the fix could hopefully be done on a cave wall using a flint spear tip.
Or set 0 to be the Big Bang and make the type unsigned. Do it the same time we convert all temperature readings to Kelvin.
And count Planck time instead of seconds.. it's not as impossible as it may sound. You'll need more than 128 bits but less than 256 bits even if the epoch is the Big Bang (I can't recall exactly how many bits are needed, but I did the math once, some years ago). And it'll be compatible with alien or future time systems too, in case what we call a second (currently defined by caesium-133 periods) changes.