[time-nuts] GMT vs. UTC

[Magnus Danielson]

From: "Poul-Henning Kamp" <phk at phk.freebsd.dk>
Subject: Re: [time-nuts] GMT vs. UTC 
Date: Tue, 21 Nov 2006 17:53:10 +0000
Message-ID: <2598.1164131590 at critter.freebsd.dk>

> In message <20061121.184838.-432831398.cfmd at bredband.net>, Magnus Danielson wri
> tes:
> 
> >One has to understand the reason for my question, which stems back into the
> >legalities of things. Can we state a time event in GMT and relate that back to
> >our "non-political timescales" of TAI and UTC (UTC has politics around it for
> >sure, but those are on the leapsecond aspect) which we methods for transporting
> >and realizing, and then say with certainty that this time is _known_ in a legal
> >sense. Especially, can we do this in some other country than GB?
> 
> Well, if Sweden defines their time to be GMT+1h and the british parliament
> changes GMT, then in a theoretical world, Sweden changes along.

Indeed. Fortunatly Sweden has defined itself in UTC.

> In a practical world, people write GMT when they mean UTC half the time
> and therefore Sweden would not follow GB.

Yes, but the trouble is when you try to check the traceability in law, then you
can end up in the wrong end of things. This is why I both want to know the
actual definition of GMT and want to have people stop using it incorrectly
where it actually has an incorrect meaning. Dreams, dreams...

> Since UTC is a UN controlled standard, it is a much safer reference.

I agree. 

Then again, UN is a very political place. :P

Cheers,
Magnus