I see no reason to migrate from GMT. Ultimately, there's only one time - now. And it's now everywhere. For those in requirement of a little more measuring accuracy, atomic clocks do indeed seem suitable - What doesn't is the concept of "time zones". Unless you're travelling immense speeds between places, or having a differential like the inner and outer of a galactic spiral, offset for velocity isn't likely to be much of a concern and sync to an Earth-orbit Atomic clock via quantum entanglement to me sounds the best way to "standardise time" across infrastructure. I think there's a reason why people stopped counting fingers like that at or round about the end of the Roman empire - and it'd certainly not make any sense to anyone educated in the metric system. Sure, week/month/year - even days, really - have pretty much no significance outside of Earth. Seasons even less so. Having no observable carcadian rhythm I would readily adapt to any given pattern. However, humans have evolved this over tens of thousands of years and as such might represent a particular issue with regards to dealing with. Any "evolution" to cope with this adjustment isn't likely to be a rapid thing. In order to minimise for impact this is sensible to maintain to "Earth format", I've noticed humans don't seem to work too well 72hrs into a day for example. Sticking to Earth format also establishes ties to heritige, something that may become important later.

For now, the UTC is fine. As for long term: Isn't referencing other object in space not as optimised as they are changing non-stop? I think it's important to keep the definition of second, consider how many formula, equations, definition etc are based on it, changing it without a proper reason is just a waste of time and effort. As for minute, hour and day, if there's not a major reason to change it, we should leave it as is, consider how is it easily divisible and how they are connected to us. (If you count the joint of your finger using your thumb, there are a total of 12 joints excluding the thumb). However, for week, month and year, there's not really much reason to keep using the same. There isn't really much reason to have 7 days a week in modern day other than it is just an old tradition that no one want to break. As for months, although it is related to earth's season and such, I agree that once we leave earth, it is no longer important. As for **Onegin** stated that: >But they are in your genes and your brain. Humans experience both monthly and annual biological rythms, which makes years and months make sense. Animals exposed to deviations in outer ryhtms, even annual ones, experience erratic behavior and age faster. We are already going to be subject to a lot of strange stimuli up there, so I would suggest to keep things traditional. I actually doubt that once space travel become a norm, this will still be a case, consider us human evolved on earth to suit ourselves on earth, I *think* once we no longer inhabited on earth, we may start to evolved away from those rhythms. Though I'm not an expert of the subject, so I can't say for sure.