On Mon, Sep 26, 2011 at 4:13 PM, Clive D.W. Feather <clive@davros.org> wrote:
Tobias Conradi said:
No, the law here says legal time is GMT, but most official time signals are UTC. There have been a few unsuccessful attempts to deal with the mismatch between de jure and de facto UK time, e.g. http://www.publications.parliament.uk/pa/ld199798/ldhansrd/vo970611/text/706...
So there is one flavor of GMT that is UTC and there is legal GMT which is something different.
Yes and no. Which part you refer to by "no"?
2011i/tzdata equates GMT for 2011 with UTC.
In effect, yes. It takes the view that the difference is too small to matter *in this context*. I personally would rather not guess what view it has, but stick to what it does.
So if country A says its legal time is an hour ahead of GMT and B says they are an hour ahead of UTC, those are technically different statements.
To my understanding the statement of country A is ambiguous. Whether there is approximation in tzdata depends on how one interprets the the statement of country A.
No. The statement of country A is *not* ambigous (except at the millisecond level as mentioned above). Since there are different types of GMT it is. There is the legal GMT which is ambiguous in itself and the BBC-GMT.
The statements are technically and de jure different. Yes, the first is ambiguous.
Whether country A actually meant UTC when it wrote GMT is a separate question that you'd have to ask country A.
This has nothing to do with ITU-R TF.460-6.
But the proposed amendment to it would mean that "too small to matter in this context" will cease to be true eventually. GMT is not mentioned in the document http://www.itu.int/dms_pubrec/itu-r/rec/tf/R-REC-TF.460-6-200202-I!!PDF-E.pd...
Also, since there is a time span when GMT was legally defined different from UTC, I think an ITU document cannot change that retroactively. In the linked document I also see no change of definition of UTC. -- Tobias Conradi Rheinsberger Str. 18 10115 Berlin Germany http://tobiasconradi.com