To what extent is light level effected by latitude?
The farther away from the equator you go you never get the sun directly overhead; until at the poles it's always on the horizon. I'm not sure how that would affect plants in a greenhouse on Antarctica, since plants tend to grow towards the light.
---------- Post added at 08:28 PM ---------- Previous post was at 08:22 PM ----------
As I think about this, I wonder if it would be a good idea to redefine the SI second to be a multiple of both the Martian and the Terrestrial solar days.
Mars is the only planet we may live on that has a day similar to Earth; so it makes sense to standardize time for those two planets and forget about the rest.
We could call the new second by a new name, maybe, to reduce confusion with the current SI second.