Dear etaoin: I hope this is not coals to Newcastle: here is a paragraph about timekeeping on Mars:
In seeking a martian time standard and calendar system, we should be driven by the
practical needs of those who will, in the not too distant future, be working and living in
the Martian environment. It will no doubt be some time before an extremely accurate
local standard is available there. Calendar constructs based on terrestrial analogy are
useful since they can be easily understood by all and they may incorporate
psychologically valid ideas (e.g., circadian rhythms). Consequently, the same terms may
be used to refer to somewhat similar constructs in the martian and terrestrial contexts. To
avoid confusion, we will adopt the practice of referring to the martian analogy of a
terrestrial quantity by using the prefix areo- (from the Greek Ares for Mars). For
example, the martian equivalent of a day has long been referred to as a sol (a more
precise definition is given below). If Martians were to make use of an interval of 7 sols,
corresponding to a terrestrial week of 7 days, we would refer to this unit of time as an
areoweek.