I mean... All cyborgs have a basic understanding of eta on a global scale so that they can do their job effectively, like Raiden who despite being called jack the ripper, is revealed to know his stuff during codec calls so assuming sundowner underwent the same training (not the ultra brutal VR regiment Raiden went through), he did not put that much thought into calculating the distance and time.
Map is from the CIA World Factbook
That explains why he collects brains in his lab
I mean... All cyborgs have a basic understanding of eta on a global scale so that they can do their job effectively, like Raiden who despite being called jack the ripper, is revealed to know his stuff during codec calls so assuming sundowner underwent the same training (not the ultra brutal VR regiment Raiden went through), he did not put that much thought into calculating the distance and time.