How to coordinate the clock when dual-booting with Windows

Peter Silva peter at
Sun Dec 10 17:00:38 UTC 2017

If you don't know your timezone, then you don't know what time it is.
This relative/absolute dichotomy is a red-herring, because time isn't
only used within one frame of reference.
Time is very often use to co-ordinate things among people who aren't
in the same frame of reference.   It's just like timezones, only worse
with Einstein because now time doesn't even run at the same speed.
How do you schedule a meeting between someone on earth and someone
orbiting at a speed where relativity is an issue?

You need a means to map the various relative times to the standard
one, and then communicate in the standard time reference.   This isn't
at all academic.  All (LEO) navigation satellites are built to
account the fact that the atomic clocks on board are running slower
relative to the earth because of their relative velocity to their
users. All navigation systems use UTC because anything else would be
totally insane.

On Sun, Dec 10, 2017 at 11:38 AM, Xen <list at> wrote:
> Colin Law schreef op 10-12-2017 17:11:
>> I understand the original question now, the solution to MS's garbage
>> (though that might just be my view) system is tell Ubuntu to do the same,
>> using timedatectl as suggested by Xen. I gather there are windows registry
>> mods one can do to change the way Windows does it, though there is debate
>> about the reliability of that.
> Well personally I think the issue is whether you will use relative or
> absolute coordination.
> We humans like to think we are the centre of the universe and that
> Greenwhich is that.
> And then we try to use absolute coordinates.
> I think if we ever became part of a space-faring society we'd realize that
> relative referencing is a lot more stable ;-).
> (Or if we understood Einstein better :p).
> IPv4 NAT is a form of relative, IPv6 without NAT is a form of absolute.
> If you use relative referencing your system can easily be integrated into a
> bigger system, if you use absolute, it can't, but needs translations at ever
> border.
> Not only does it need translations at every border, you also now need
> multiple addressing systems at the same time, or absolute at border addresses.
> It's a bit like using relative symlinks versus absolute ones.
> Absolute ones break immediately and require chroots to keep functioning.
> The "chroot" is equivalent to the "@border" address.
> So the Linux people say: use UTC with timezone.
> What if you don't know your timezone?
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