Our current time system has multiple bases - base 60 for seconds and minutes, base 24 for hours, base 7 for weeks, base 12 for months - and that’s an approximation, of course.

What if we just told time in seconds?

  • 100 seconds = 1.67 minutes
  • 1000 seconds = 1 kilosecond = 16.7 minutes
  • 10000 seconds = 10 kiloseconds = 2.78 hours
  • 100000 seconds = 100 kiloseconds = 1.16 days
  • 1000000 seconds = 1 megasecond = 1.65 weeks
  • 10000000 seconds = 10 megaseconds = 3.81 months
  • 100000000 seconds = 100 megaseconds = 3.17 years
  • 1000000000 seconds = 1 gigasecond = 31.7 years

Or, if we want to approximate our current time references, here’s what we’d say

  • 1 hour is close to 4 kiloseconds
  • 1 day is close to 100 kiloseconds
  • 1 week is close to 1 megasecond
  • 1 month is close to 3 megaseconds
  • 1 year is close to 32 megaseconds
  • 1 century is close to 3 gigaseconds

And it’s certainly a lot easier to compare kiloseconds to megaseconds than it is to compare hours to weeks.

Once we go into space for real and start living in orbit or on other planets, “day” means something very relative, and so does “year”. So we will have to give up parochial time spans and go to something useful, and it could be as simple as SI prefixes combined with seconds.

Credit to Vernor Vinge for being the first person I saw writing about this, in A Deepness In The Sky (1999).

And now that I search, amusingly Wikipedia has pages for megasecond and gigasecond, where someone has listed various time durations in fractions of these values.

I hadn’t thought about it, but Gigaseconds covers human history, since the next biggest step up, terasecond, is talking about timeframes in units of 31,588 years. And teraseconds covers the range up through 32 million years, which is a respectable amount of time.

And the universe is less than half an exasecond old.