If you want one-second resolution, sure. If you want nanoseconds a 64-bit signed integer only gets you 292 years. With 128-bit integers you can get a range of over 5 billion years at zeptosecond (10^-21 second) resolution, which should be good enough for anyone. Because who doesn’t need to precisely distinguish times one zeptosecond apart five billion years from now‽
Good point. You’d need at least 215 bits to represent all measurably distinct times (in multiples of the Planck time, approximately 10^-43 seconds) out to the projected heat death of the universe at 100 trillion (10^14) years. That should be sufficient for even the most detailed and lengthy simulation.