How is one hour in space equal to 7 years on earth?

The first planet they land on is close to a supermassive black hole, dubbed Gargantuan, whose gravitational pull causes massive waves on the planet that toss their spacecraft about. Its proximity to the black hole also causes an extreme time dilation, where one hour on the distant planet equals 7 years on Earth.

One hour is too long in space? Do they wear the same watch like what we wear?

There’s only one “official space watch” in the world, and it’s the Fortis Cosmonauts Chronograph. This Swiss-made tool watch cleared all tests by Russia’s space agency ROSKOSMOS over the course of 6 months, and in 1994 was awarded an exclusive 25-year contract as the agency’s official space watch.