Given an age in seconds, calculate how old someone would be on:
- Earth: orbital period 365.25 Earth days, or 31557600 seconds
- Mercury: orbital period 0.2408467 Earth years
- Venus: orbital period 0.61519726 Earth years
- Mars: orbital period 1.8808158 Earth years
- Jupiter: orbital period 11.862615 Earth years
- Saturn: orbital period 29.447498 Earth years
- Uranus: orbital period 84.016846 Earth years
- Neptune: orbital period 164.79132 Earth years
So if you were told someone were 1,000,000,000 seconds old, you should be able to say that they're 31 Earth-years old.
If you're wondering why Pluto didn't make the cut, go watch this youtube video.