On 17 Feb 2016 at 6:53, Greg Chalik wrote:

> Synchronise planetary orbits also?

No, this is why you have to distinguish between "local" (planetary)
time and "standard" ("universal") time in a society that encompasses
more than one planet.

The Mars Landers have already established the "sol" as the local
solar day on Mars. I'm of the opinion we should generalize that to
all planet that we'll be spending enough time on the surface of to
care about the local day.

You *need* to call it something different to avoid confusion. 30 days
is a lot different than 30 sols.

A Martian sol is 24 hours 39 minutes 35.244 seconds, or 1.03... days.

So 30 sols is a bit under 31 days (30.8)

For planets with bigger differences between their sol and a day,
things get out of synch a lot faster.

Likewise, you don't want to divide the sol into hours, minutes and
seconds, as that can result in dangerous confusion as well. Some
authors have used div(s), others dura(s), and I suggested peri(s) in
several previous discussions of this sort of thing.

How many should be in a sol depends on the length of the sol. some
numbers make it easier than others to divide up the sol for various
purposes without involving ugly fractions. Or you can just go
decimal, and deal with the fractions.

There needs to be a generic term for "local year" as well. Something
that won't get confused with "year" or "annum".

Months aren't a big problem since they vary in length on Earth anyway
(though they don't in the Imperial calendar. even so the Imperium
doesn't really make much use of them).

Weeks? Who knows? a complicating factor with them is that most
religions have a 7 day week cycle built into them. and even on Mars,
trying to use a 7 sol cycle instead would quickly get them out of
synch with Earth.
--
Leonard Erickson (aka shadow)
shadow at shadowgard dot com