[ymolodtsov]

On the Moon or even Mars it's a bit irrelevant because you're not following the Sun anyway.

But let's talk sci-fi: what if there is a habitable colony where the day is 26h30m. What do you actually do?

[all2]

In some of the scifi books I've read there's local time and there is 'sol' or 'earth' time, where 'sol' or 'earth' time is the absolute time, and the local time slides by the absolute time.

So... not time 'zones', per se, but time 'frames'.

[perilunar]

I think that once a large number of people are living off-Earth, we should just use Unix time to coordinate and for all technical work.

Planets can use a local solar time and calendar. Habitats in free space could just move to Unix time and use a 100 kilosecond day.

[ymolodtsov]

Yes, but what do you use in life? What's on your watch?

[perilunar]

Ideally, whatever time is used locally, UTC, and Unix time.

[kps]

I get to sleep in. When do we leave?

But seriously, the ‘second’ becomes a purely technical unit, and you have some other suitable local units.