Even our sense of time comes from them. The time it takes the Earth to spin on its axis; the Earth to go once around the Sun. On Jupiter, you’d be celebrating your first birthday. It’s hard to feel we matter out here, isn’t it? The distances are so vast—it’s hard to believe that we can make a difference.
This is actually how it’s handled in the science fiction universes. Star Wars for example uses Corusant time as the standard across the galaxy.
Belters in the expanse are bitter at their colonial ancestors for dictating how they measure time and space