I was 100% thinking of use by humans living on other worlds. Pretty sure Mars will use seconds and hours. Handling dates will awkward whatever they decide on.

I was 100% thinking of use by humans living on other worlds. Pretty sure Mars will use seconds and hours. Handling dates will awkward whatever they decide on. Currently, a Mars days is called "sol", FWIW. If we find other species out there I won't speculate on how they think about time.